Check the prices now. The XH-1 is a great deal, better in fact than the XT-3.

The front element of lens will likely be the same in order to capture the same level of light available. For crop sensors, the lenses get smaller, but not much comparing to full frame sensor bodies. If image stability is incorporated, the lens becomes larger but not by much. However, Canon and Nikon employed is diffractive optics that reduce the size and weight, but at the expense of cost! Nikon makes a 300 mm f/4 P lens that costs over $2K and Canon offers one 400 mm f/4 DO IS that costs $6K.

Mirrorless bodies require more battery power of the EVFs. A single Fuji battery pack provides about 300 shots, whereas DSLRs provide more than 1,000 with the optical viewfinders.

So it is all about trade-off. It is unlikely there will be significant size reduction. Even Sony stopped advertising "smaller and lighter". Their lenses are similar size as Canon and Nikon.

You are drinking coolaid. The other poster is correct, a big heavy lens supports the camera, not the other way around.

No professional in the world death grips a camera without supporting the lens.

Google it.

For very large lenses, yes, the lens supports the camera, but there is a whole list of intermediate lenses that are not big enough to support the camera, but still pretty large (16-55 f2.8, 90mm f2, etc).
At some point, the 5~10% difference in size with the X-T2 is not really significant, given the larger grip and additional size for the manual control.
At least it gives people a choice.

And a D500 it ain't

thats true the d500 isn't as compelling a camera, and is large and unweildy as dslrs tend to be

@cosinaphile: The D500 is more compelling and associated with sport and wildlife shooters.
You would tame it with a 400 f/2.8 on a monopod, in no time at all. :=) if you need too.

If it's not a value proposition for you at that price, there are lots of other $2000 options available to you, including a M4/3 camera that costs $100 more. No one is twisting anyone's arm to buy this camera.

"I like Fuji OOC colors but the price is beyond absurd"

Yes expensive, but when I count in that in each and every shot with Sony I have to "optimize" the ok-ish, but not great color and yet struggle to get near the stunning color a Fuji outputs (in Jpeg and Raw) effortlessly in each and every shot, it is not expensive. Because getting ready pictures in only a few clicks as opposed to intense editing is a huge time saver. After 10.000 shots and more it starts to save you weeks of lifetime.

A comment about price being "beyond absurd" invariably means the writer:
1. Cannot afford it.
2. owns a different brand .
3. Does not understand or care about marketing, product placement
4. Thinks the comment is clever, especially if it relates to Leica or, to a lesser degree, anything related to medium format.

Wait until Sony announces the a7000. I bet it will be over $2000.

That's because it has a key "buzzword"....MIRRORLESS.
That's like when the smartphone prices go up because they
have the key words "colorful, thin & stylish".

Get them when their cheap now, before the XH-2 comes out at a higher price.
No, never mind.

You said Fuji's bigger size is a con, but there are many photographers who find the Sony to be cramped. Whether that is enough to sway them to an "only APSC" LOL is subjective and debatable. I predict Sony now puts out a larger A7 body and then Sony fans will call the larger size option a great thing.

Fuji X-H1 packs better body (weather resistant), better IBIS, better lenses, better ergonomic, better display, better EVF. ..

For many, theses features are more important als 1 stop better noise control.

So X-H1 may be better for some... out of the pure specs

The future is your phone.
The traditional camera, whether m43, APS-C, Full Frame or Medium Format, is just a niche product.

@Marksphoto
The X-H1 is neither smaller nor lighter when you compare it to the current FF 3rd gen A7 and equivalent Sony lenses.
Fuji has many things going for it but not does not deliver the same performance at a smaller size and lower weight. It can only be one of it.

The size and eight of the x-h1 is generally better than Sony when paired with G master glass and Fuji glass is amazing. Don’t look at the camera itself. Look at the combo. The x-H1 is also built like a tank.

Sony's GM glass has been oversized, overpriced and generally underwhelming. In contrast, their new 85mm F/1.8 FE is probably the best glass in their entire range, Zony Seiss lenses included, and appropriately priced to boot.

But yes, Fujifilm does have a better range of lenses than Sony, in general. That's a compliment.

@noflashplease
"In contrast, their new 85mm F/1.8 FE is probably the best glass in their entire range"
- There are actually two 85mms in the Sony range which are better.

@noflashplease
GM lenses support at least 50mp+. That's why they are big and expansive. APSC doesn't even have high megapixel sensor like 42mp.

@pro photo 2011
There are the Batis 21mm f2.8 and 25mm f2.0, Loxia 21mm (soon also 25mm) and 28mm f2.

@Marksphoto
Superior IQ in what terms? The new Fuji cameras have:

- higher resolution
- better ISO performance
- higher dynamic range

They are superior sensors by every metric. Maybe you are used to a specific look to the 5D2 files but this is highly subjective.

@Marksphoto
I have tested systems from the 4 big players (Fuji X-T2, Canon 5D4, Nikon D850, Sony A7R3) for at least 2 weeks and up to a year depending on the model. I bet this is a more diverse experience than you ever had.

I know that Canon color science has changed but white balance is only an issue in JPEG and video. Only if you are a fool who fails to even do the most basic post processing work this is an issue.

If the future is full frame then they will have to figure out how to make smaller lenses.

Yep. Fuji underexposes by 2/3 stop, which is why everyone thinks Fuji cheats ISO. But when comparing, instead of pushing the exposure people raise the ISO to try match the non-Fuji exposure.

Oh, yes, I had almost forgotten that crap about "cheating on the ISO." Sigh....

Yep...thats why they dont blow highlights like FF Sony

Sorry guys but you guys seem confused. Cheating ISO and different metering behavior aren't the same thing. Different metering is when the camera, given the same scene, metering mode and lens's aperture, tells different shutter speed or ISO dependent on which mode you're on. While in Max's video the Fuji's footage is clearly darker while using the same setting as the Sony's, that's cheating. That being said, this weird decision of Fuji won't do any favor for Fuji's users except making them feel good about their cameras. The Fuji might look as good or better than another camera at the same ISO by number but in fact, gives only half of the exposure value that the other camera does. And speaking of exposure value, the other camera might just need to lower its ISO by half to get much less noise while still maintain the same ev as the Fuji

tests vbeasr out that fuji not only has a different iso structure and mandate , but alsao tends to.... compared to others...underexpose at 0 +_- by about 2\3 stop

result ,? less blown highlights

The game is called "unobtrusive photography", and now he can do it without wrapping his camera in a catcher's mitt.

He should get a Ricoh GR then. Better tool for this. Still the same game..

An obtuse argument if there ever was one. I own both brands and love them both, but to say a Ricoh GR is a professional camera compared to a XT-2 or XH-1 is stretching it by a large margin. Thanks unless if you think taking all your photos within a 2M distance is possible in a film studio.

The man loves the camera for his job. It is a good thing. Why would you disagree with any of it?

i agree , i found the tone and conclusions of the written review dismissive and a bit off the mark .... this camera is a pro camera without compromise for those who earn their living with a camera ... it is the most capable , stills and video camera fuji has ever produced , there is no stills centric fuji camera that outdoes it

i find it large , but for many the handling will be improved in a pro setting

When someone here says product XYZ is "overpriced," it means:
1. He can't afford it.
2. He owns a competing product.
3. He really does not understand marketing, product placement, demand.
4. Trolling.
Leica especially brings out the economic experts.

Or perhaps when someone says XYZ is overpriced, it really is overpriced.

Well, Leica is overpriced, for its image quality and performance

Again with that "amount of light?!"

FF sensor receives EXACTLY THE SAME AMOUNT OF LIGHT over the APS-C sized part of it.

No, F4.2 on FF does NOT put more light on sensor than on APS-C (looking at the same area).

Stop confusing people.

What are you talking about of course a FF sensor receives more light. Larger bucket. Same light per unit area but more light, more light by all means of more light.

Exactly, so exposure is the same. There is not more light per sq mm on FF than there is on APS-C, therefore FF sensors do not get better signal noise ratio because of the size of the sensor itself.

Did you even read what I wrote? I said "over the aps-c sized part of FF."

We're on the same page then.

FF sensors gather more total light than S35, just not per square area. A 1" cut out of a FF chip have identical light per square area. (See 7DII chip cut-off of the 5DSR's)

FF sensors perform better in lowlight

-Due to the total more light gathering, keeping everything else constant. Including Resolution (=larger photosites)

-Even when resolution isn't constant: meaning a larger number on FF that scales to the sensor size (7DII 20MP VS 5DS 50MP), the FF one does better in lowlight due to simple oversampling/NR cabapility. 1:1? No they're identical.

-And last but not all there seems to be faster glass for FF than any other format (in equivalent terms). I mean why can't all the manufacturers make fast FF primes and slap a Focal Reducer at the end of the optical formula?

-There's faster pace of technological progress and focus on the FF size sector compared to any smaller or larger sizes.

Guess what, you can buy the xt2 or xe3 then. Problem solved.

xmeda: drugs are bad for you...mkay?

Um no. Great camera but it struggles to match Sony apsc so pretending it comes close to Sony and nikon ff is just not true.

"Dynamic range is also good: a little behind the very best of its APS-C peers."

Nice fanboy comment @xmeda

Pro chose ergonomics, reliability, service, lens selection. Amateur can go for spec only. How many pro bought the A9? Xh1 is designed for pro.

Thermidor while I am a fan of Canon Panny and Sony cameras, I am not a fan of heat disspation due the diminutive size factor of panasonic and Sony MILC when used in video, the increased size may be to avoid overheat issues which plague small form MILC.

@DarnGoodPhotos

I'm not asking for the level of stabilization of the X-H1 to be replicated across their existing lines. The X-H1 will be its own flagship, and I respect that. I'm just saying people would really like some form of IBIS onto smaller bodies. Even if it's a 3-axis stabilization, or up to 2-3 stops as compared with 5.5, it's still more than good enough for most of us.

@Vanitas Photo

Agree on that aspect. I have a Pro 2, and it gets hot even for stills shooting, so I can't imagine myself shooting 4k on it much. But at the same time, most casual users aren't doing serious video work, so heat isn't as much of a problem as shakiness, which is why some form of IBIS would help them.

Heat on Sony cameras is a non issue with their most current offerings (A9 & A7)

A6500 ibis is the worst in the business.

I've never heard Dpreview speaking of a "significant disadvantage" of APS-C versus FF. I know the theory of that one stop advantage. Did never sound too significant to me.

But the full frame of 2017/8 will outperform the Fuji of 2017/8 for image quality. The question is , do you need this extra image quality and can you appreciate it? In fact , the truth is, except for special cases, apsc delivers enough image quality (and especially when used with good fast prime lenses) into a smaller package vs full frame. And for special cases / professional use, medium format enables more than full frame. apsc is not Fuji, other brands also offer apsc and they are a lot cheaper than Fuji. Fuji pricing for apsc is rather aggressive, based on the fact that the masses will never print large and mostly use internet sharing, Fuji has said that apsc is as good as full frame, this is not true but commerically speaking their strategy works very well because more users will buy it and will never see the difference between aspc and ff at small enlargement. As Ansel Adams said, the best format is the largest you can carry with you.

Lamely disingenuous.

It's perfectly natural to compare a camera with similarly priced competitors in a summary.

As for one stop not making a difference... I have based buying decisions based on one camera being half a stop better than another. When scrabbling about to get usable files from indoor events it very much pays for itself. And I'm talking about real difference, not cooked raw files and 'waxy' skin tones.

Giving X-H1 86% SILVER where as X-T2 is 86 GOLD doesn't make any sense whatsoever. X-H1 does everything that X-T2 can but also delivers lot's of new in terms of video. DPREVIEW sorry but this is a joke.

It's not illogical, if you understand what the scores and ratings mean: https://m.dpreview.com/articles/4416254604/camera-scores-ratings-explained

you got me curious,so i read dprs on the scoring logic[.thanks for posting that bill.] from the article: [as regards gold\silver awards]

"These awards are meant to be hard to achieve. If a new model raises the expected performance level for a class of camera, then that's the one you need to match to get a Gold. In other words, simply doing as well as a camera that got a Gold in the past may not be sufficient."

now having read that , &considering the xt2 which got gold . I see the h model as having every bit of goodness,IQ wise, & in terms of performance
but the h is the camera that finally makes fuji respectable for video
, that in itself is a major achievement & a sign of,not only growth,& added breadth to this models abilities,but also:
1} overcoming the last hurdle to mirrorless handling ,big grip[for DSLR users]
2} providing IBIS [a profound advance for fuji bodies ]
while the batteries the same, a config. [with added grip] for longer power.

gold, not silver, was callled for.

The idea was to highlight some of the strengths of X-H1. I have a Sony A9, so fully understand what you mean -- and I have the Sony 28mm, 50mm macro and 85 lenses. (I am not looking for weatherproofing, but the sturdiness of a camera like X-H1 stands out, compared to Sony FF variety..)

But, staying on the topic at hand, i.e. Fuji X-H1, This DPR review officially concludes rather harshly and confusingly -- by the editors, that is --

"Not so good for": "Anyone looking for the perfect tool for one specific job".

And so I had to point out some things that really stand out, like the Shutter quietness, not to mention the simplicity of Fuji user interface, though some would disagree with me :-)

Ebrahim, do you think the price of the camera is only based on sensor size?
wouldn't the mechanical side, EVF etc. factor into pricing... All this items are not free and they cost more than the sensor itself.
the XH1 build quality is better than the A7_III build
why don't you say the same about 5D4, 1DX, D5 etc... they're more expensive than A7III and on spec sheet, A7III looks like a bargain compared to these.

Fox: yes of course with any investment into a Fuji lens line up, the XH1 is definitely the way to go.

Vignes: no it's not just sensor size, but it IS a big part of it. And the A7III is not just better in sensor size, even if it was APS-C it would be a hell of a strong competitor to the XH1, but no, it has the best 24mp 35mm sensor ever made. That's something. Image quality. And your claim on build quality, I am not buying it unless I see it tested. They look the same size and overall built to me. And yes it's a huge bargain against the 5DIV (the 1DX/D5 are too different to be mentioned)

XF10-24F4=$1000 | FE16-35F6.1 (doesn't exist, but there is $1250 F4 version equivalent to XF10-24F2.5)
XF16-55F2.8=$1200 | FE24-70F4=$1100 (which is equivalent to 16-55F2.5) and FE24-105F4=$1300 (which is equivalent to XF16-70F2.5)
XF50-140F2.8=$1600 | FE70-200F4=$1400 (which is equivalent to XF50-140F2.5)
and so on ...
And you can check the size and weight, there is no advantage in crop optics.

Ecka. I think you forgot to add "...if you use Fuji's largest lenses."

However, if you use their smaller bodies, primes, and zooms there is an advantage to mirrorless APSC.

I find funny the price comparison between Sony and Fuji lenses based on aperture equivalence. For instance take the Fuji 10-24 f4, should it really be f2.8 to match the FE 16-35 f4 ??? it's an ultra wide angle lens, aperture will matter mostly for exposure and there, when I compare my X-T20 and A7 II at ISO 6400 I don't see any advantage on the FF side (but I can feel the 300g more). Ok, A7r II and later cameras do have one stop advantage in ISO sensitivity but at what cost?

Comparing the 16-55mm 2.8 to FE 24-70 f4 can't be just about price or weight, given the bad review of the FE lens... However I agree when it comes to longer lenses like the 50-140mm f2.8, I bought a cheap Canon 70-200mm instead that works very well on the A7 II.
Finally, I agree with some comments above: Fuji has cheap primes that are sharp wide open. Let's take the Fuji 50mm f2 for instance, is there an equivalent that is that sharp, small, light, and cheap (did I mention WR) on Sony's side??

"Fuji 10-24 f4, should it really be f2.8 to match the FE 16-35 f4 ???"
- No. It should be F2.5

"when I compare my X-T20 and A7 II at ISO 6400 I don't see any advantage on the FF side"
- That's because Fuji are liars and cheaters and their ISO 6400 actually is ISO 3200 and you can clearly see that when you compare histograms on the actual cameras side by side in the same lighting conditions.

"... Fuji 50mm f2 ..." ($450)
- Why would you need a "cheap" FF 75F3.1 anyways? Just for a smaller package?
Photography isn't about putting small cameras in your pockets.
Actually, I can use a much cheaper ($200) FF 50F1.8 on a much higher resolution FF camera and make 75F3.1-like crops (and many other) out of those images, easily. Or keep the original, which is equivalent to XF35F1.2 (you can only dream about at $200). Yes, that camera costs a lot, but it makes up for not having to buy the whole bunch of small, slow, overpriced crop toy lenses.

f2.5 doesn't make any sense as a specification for a zoom lens and again, for a UWA lens aperture is only about bringing more light, as you're not looking for DoF or best bokeh. In that regard f4 is f4, no matter what the sensor behind the lens is.

Sorry, but you're going to have to prove that "I can crop my FF + $200 and get the same IQ than your APS-C $500 lens". To me it's like saying I won't be the Olympus 40-150mm f2.8 because this is actually a 80-300mm f5.6 so it won't be better than my Canon 75-300mm 4-5.6. You see what I'm getting at?

Ok, we've heard it many times, Fuji lies, etc... I'll do another test, just for sake of arguing... in the meantime, I'd say I compared some time ago a FF + f2.8 lens and the Sony RX10 with the same ISO, same shutter speed, at f2.8. Despite having a much smaller sensor the scene was brighter on the Sony. The only difference would be the noise at higher ISO. Photography is about results not numbers...

larkhon - f/4 is f/4 regardless of what sensor is behind the lens. However, that only says that each sq mm of both sensors will receive the same amount of light.

So, if we assume you're not always going to print/view images from APS-C cameras 58% smaller than you print and view a full frame image, this information doesn't tell you much.

An f/2.8 APS-C lens (APS-C lens' focal length/2.8) will have roughly the same aperture diameter as the equivalent f/4.2 lens on full frame, since that will have a lens with focal length 1.5x longer (so (APS-C lens's focal length*1.5)/(2.8*1.5)).

As such, both are looking at the same view of the scene through the same sized hole. That hole has different f-numbers on each lens, so the light per sq mm will differ, but the same element in the scene will be made up from the same amount of light (projected over a larger region of the larger sensor).

View both images at the same size and they will look similar in almost every respect.

@richard butler: every time I discuss this I wonder if I use the proper vocabulary or concepts. From what I read, different sensor size, equivalent f-stop on lens, same aperture diameter, same amount of light. But what does it tell us? if I shoot my FF with f/4.2 the scene is darker than the same one shot at f/2.8 on APS-C.

To be honest, appart from the sharpness of the lens itself, I don't see much advantage to take my A7 II + 16-35mm f4 over my Fuji X-T20 + 10-24mm f4. That's why I reacted, one cannot compare lenses/systems solely on f-stop equivalence, that's how you feed the upgrade path myth, FF will always win in the end, if not MF.

"if I shoot my FF with f/4.2 the scene is darker than the same one shot at f/2.8 on APS-C."
- That's because you are not using equivalent ISO values (and you should).

"one cannot compare lenses/systems solely on f-stop equivalence"
- It's not just "f-stop equivalence". It is overall equivalence in every aspect, which allows you to reproduce an image via a different format camera. Because it is all about the image after all.
Crops cannot reproduce FF ISO100 16-35F4, because for that you would need APS-C ISO40 10-24F2.5. Math doesn't change, only some relative and made up numbers change, while the amount of light stays the same. And that's the whole point of equivalence.

of course FF can take shots the crop cameras can't, and that is why I'm keeping the A7 II. But to me it makes less sense to buy only into FF considering the size, weight and price when alternatives are available and good enough for what I'm intending to do with it. For instance I don't see the point in dragging the FF on a city break where I'll be walking all day with my camera. With the weight I gain I can bring a couple more lenses (even bodies) with me...

About ISO-equivalence, I don't think it exists, simply because it is too much dependant on technology. Just compare A7 II and A7 III, it seems that with higher ISO one stop can be gained.
I did a quick test yesterday and I'll give you one thing : if I shoot with the same ISO into a light, there seems to be more light (or less DR?) on the FF side. Otherwise I don't see much difference, either noise or brightness (considering exposure is maybe not the correct word) in the scene.

There is no size, weight and price advantage in crop systems. There are only compromises that can make things smaller, for any system. APS-C and FF difference is bigger than F2.8 vs F4. Just stop ignoring it.
If there was a huge, heavy and (I imagine) crazy expensive XF16-50F1.8, which could produce images very similar to FF 24-70F2.8, would you still buy one? The fact that there is a FF 24-70F2.8, doesn't mean that you have to use it. Fuji just doesn't have the option, there is no XF16-50F1.8.
"ISO-equivalence, I don't think it exists" - It's not a matter of opinion. There are no separate equivalences for each and every button on your camera. There's only one equivalence and it works for everything simultaneously. And you can't apply it for just one thing (like focal length) while ignoring the rest.
56F1.2 on crop is not equal to FF 85F1.2, because it is equal to FF 85F1.8.
56F1.2 ISO400 on crop is not equal to FF 85F1.2 ISO400, because it is equal to FF 85F1.8 ISO1000.

Well, you can believe it if you want, and please try any recent APS-C body with a decent lens. I'm shooting both FF and crop, and M43 for that matter, and my experience is that FF is not the one answer that answers all for me.
No, I would not buy a XF 16-50 f1.8 because obviously I could find a better option on the A7 II. But I have however a Sigma 18-35mm f1.8 on my D7200 that is a bit heavy but not really expensive. Of course I could sell all and get a GM lens but do I need it?
About equivalence I suggest you read the article made by DPR on the topic. I agree it gives, as a whole, a notion of how the system will perform, but when it comes to ISO it can't work as a rule. FF f4 is roughly APS-C f2.8 all the time, no matter if the camera is from the 1950's. Canon 5D is also FF and will have more noise than recent APS-C cameras and won't do ISO 6400. Therefore this can't be a rule.

Feels like you're not even reading what I'm saying. From the start I was mentioning the progress made by the A7 III, and in no way am I saying smaller sensors are better than FF. And once more, I agree that top lenses on crop are too expensive. However I don't see that much of a difference between pictures taken by my A7 II and my X-T20 for the use I have, which is mainly landscape photography. And yes, I do have a 32" UHD monitor.
And how is half the light on a smaller sensor making that much difference? if we follow this principle to the letter, smartphone sensors wouldn't get any usable light at all. Yet they do, and if you take a picture with the same parameters, let's say 24mm f2.8 1/60s ISO 100, on two different cameras the scene will have as much light (give or take light transmission on the lens, actual ISO, etc...). Of course there will be less noise on the bigger sensor depending again on technology and size of photosites.

Please just take a look at dpr's studio scene and you'll see that A6500, for instance, is at least on par with the original A7 when it comes to noise. I won't even talk about Fuji since we were all fooled and have underexposed shots... ;)

Why the MFT 40-150 f2.8 over a FF lens? I agree it doesn't make sense if you own both but the Sony 70-300mm is not in the $500-$1000 range. I preferred the 12-100mm f4 IS that allows for a 5s handheld shutter speed at 24mm eq. As with all 'toys' fun is part of the experience...

"You think that nobody needs better cameras than you do." No, that is why I said 'for the use I have'. On the other end you focus on the shots where FF does make a noticeable difference denying any experience others might have.

"The amount of light has little to do with image brightness." exactly, why should I care as long as the end result is the same, the picture is not underexposed? I don't care if it is ISO 1bn as long as two pictures from different cameras look the same

The a7 sensor underperforms while the a6500 (and X-T20, since it's likely to be essentially the same sensor) performs very well. This will narrow the 1.3EV gap in terms of the difference in total light they get.

Light per unit area is the same at matched exposure but if two sensors have different areas then they get different amounts of total light. And total light available to the sensor, with some correction for how efficient the sensor is, is pretty much the best predictor of noise/IQ.

Though it's worth noting that small sensors tend to be more efficient, since they tend to have more advanced technology than large sensors (which inherit older technologies as the fabrication lines are replaced with finer-scale ones for the next-gen of smartphone sensors). Large sensors can get away with being a bit more wasteful of light.

I'm not trying to convince you to buy my camera. When you talk about logic I'm sure you understand that "not everyone needs to put that kind of money for DoF and, depending on the body and lens, better IQ" is not the same as "nobody needs that".

When you say "It's a spectrum of things leading to a higher or lower amount of correct information the image contains." it doesn't say anything really. It's like, "ok, some crop camera can handle the noise as well as FF, with the same DR, but still any FF must be better because it's logic".

Finally, no, you're wrong, the FF50mm 1.8 on crop body will not crop anything, physically same hole, same light coming through. So no, it's not that the signal is weaker and needs to be more amplified, it's just that the photosites are bigger on the FF and as a consequence there is less noise. Then on A7r II for example they used back illumination to gain a little light and copper wiring to have less noise.

A 50mm F1.8 will project the same number of photons per sq mm, regardless of what sensor you put it in front of (after all, it has no knowledge of such things).

However, as soon as you relate it to photography (where you're presumably composing a specific framing), it becomes more complex.

Mount a FF 50mm F1.8 on a FF camera and an APS-C camera and, from the same position, you get all the edges cropped off on the APS-C camera, which is useless. Move further back with the APS-C camera (if you can) and you change the perspective.

Ultimately, the larger sensor 'sees' a larger proportion of the imaging circle. And, since you're getting the same number of photons per sq mm, the sensor with more sq mm of surface area gets more photons. This occurs regardless of pixel size and is the main reason larger sensors are able to take cleaner images.

I agree but I still don't understand why larger sensor would have an advantage in any given situation. If I compare two lenses on different sensors, 16-35mm FF and 10-24mm APS-C with the same aperture. Considering that in both cases no light is lost because the lens is made for the sensor behind it, I only see two differences: DoF and sensor performance in terms of sensitivity, dynamic range maybe. Is there anything else?

At its most simple, it's because the same F-number gives the same number of photons per sq mm, so if you can project a larger version of the image onto a larger sensor, while maintaining the same number of photons per sq mm, then you get more photons describing every element in the scene. More light = potential for cleaner images (and, unless your sensors is terrible, then actually cleaner images).

Just to make the maths easier, let's assume your APS-C chip is exactly a 1,5x crop. You set your lens to 18mm on the full frame camera and 12mm on the APS-C camera. Both will see the same view of the scene, if shot from the same location. Set them to the same F-number (let's say F4).

The full frame sensor sees the world through a 4.5mm diameter aperture. Let's say it receives x photons per sq mm (eg you're pointing at a featureless grey sky). It receives x photons * 864mm. The APS-C sensor sees through a 3mm dia aperture. It receives x photons * 384mm (the sensor area).

Exactly. Equivalence doesn't say you need to use fast/'pro' lenses on APS-C. It says you need to use fast/'pro' lenses on APS-C if you need to match the performance of full frame.

As you say, if you don't want/need shallower DOF and are comfortable with the noise levels you get, there's no reason that you have to match the performance of something else (and accept the size/weight/cost of doing so).

But it does mean, for instance, that you could buy an APS-C camera and then a fast portrait lens, if portraits are the main time you want shallow DOF (ie: it lets you understand when and how to gain most of FF capability, without having to spend FF money on every lens, or carry FF weight with you, all the time).

And yes, equivalence only tells you about potential for image quality. The specific lens characteristics and the specific sensor performance will affect how much of that potential you can get.

As you say, the BSI 1" chips did a good job of catching up with some of the sensors a size bigger. However, you're also right to recognise that this may only 'in some respects.' But unless one sensor maker drops significantly behind, the differences are usually smaller than the differences between sensor sizes ie: 1" - (1EV) - 4/3" - (2/3EV) - APS-C - (1 1/3EV) - FF - (2/3EV) - 44x33 .

I'm not going to relaunch that whole debate but maybe what one could also consider is that smaller/lighter/cheaper lenses on FF are sometimes also worse in quality than their GM or 'pro' versions. To take an example, FR 24-70mm f4 seems to be quite average, some are even recommending the kit lens over it, considering the price. A Fuji 16-55mm f/2.8 will be slightly more expensive, slightly heavier as well, I agree, but it is sharper, weather resistant. FE 24-105mm f4 seems to be better than FE 24-70mm f4 but more expensive than both. GM 24-70mm f2.8 obviously is another better option with the aperture the APS-C can't touch, but the price is much higher.
On another topic, I bought a D800 in the meantime. It is not so much a legend that you need to watch your shutter speed and that the 1/focal length rule doesn't always work. It is a little strange though, as smaller sensors packed with pixels should also have the issue, but I find them easier to shoot with the 1/ss rule.

blind faith again, like I'm suddenly going to look at my A7 II and discover magically that it surpasses my other APS-C cameras in every way...

of course there's a difference, there's a part of marketing in buying a f/1.2 lens on m43 for instance. But I can handhold the E-M1 II + 12-100mm for 3s at least (some say 5s) and get a sharp picture when the FF would produce a blurry picture to match the exposure...
Also, is it worth spending $2000 to $3000 for the camera (Sony prices as a base), $2500 for the 16-35mm 2.8, $2000 for the 24-70mm 2.8 and $2500 for the 70-200mm 2.8 when you don't get paid from the 'superior' photos you're taking and you're never making any big prints?

For the record I only talked about DLSR because you brought up the Canon 40mm.

I guess next step is me taking two pictures and you telling me what differences there are and why they matter.

pfff... I just told you buying a f1.2 on m43 doesn't make sense for me and you're telling me "why would you buy the biggest lens available". But to answer your question I think if there is a market for those lens it's because, like you with FF, some people think they should put all their eggs in one basket and that it would too troublesome, or too expensive to buy into another system for a few interesting lenses.

As for IBIS tests on the E-M1 II:
- 1s SS is easy at 24mm (FF eq.) and achievable at 200mm. Here is a casual shot with no breathing technique:
https://s20.postimg.cc/en6h3wvgd/P5181335.jpg
- 2.5s SS now with something to lean on
https://s20.postimg.cc/9oiypdzd9/P5181332.jpg
- 3.2s SS is my limit, some claim to manage 5s but I wonder if they look at 100%
https://s20.postimg.cc/ijjszw8q5/P5181338.jpg

Of course there is a degree of shake that can be seen at 100% but I think it is ok for prints, and of course I'd like to see that done with FF.

Yup I agree image stabilization isn't exclusive for any format and will probably be all the same on every camera from a cellphone to MF backs in a few years. So yes while amazing, not really a strength for one format over the other.

I'm actually using the Olympus 12-100mm less and less since I got the RX10 m3. It's really sharp and except at 24mm I don't think there is much difference in IQ.
Yes at 100% you can see that IBIS is not the perfect solution but there are things to 'discover' ; during our discussion I was looking at 3s shots I made on holidays, and I noticed that IBIS works very well in the center and you will see the shakes on corners. It works great for fireworks or cars.
Even at home I do most of my shooting while walking with my wife and now kid as well, so there are not many occasion when I can take the time to set up a tripod... convenience is a compromise, but a photo is better than no photo at all.
I also had the 6D with 40mm (and a 24mm as well) but I replaced it with a zoom lens and that meant I left it at home most of the time... now I'm keeping the A7 II because it's still not too heavy with the 28mm and unfortunately it's lost most of its value on the market...

I think that FE 50F1.8 is twice the price, because that's Sony's way of doing things. They are always trying to seduce us with attractive pricing on one part of a system and then make their money on the other part (like lenses and accessories). Just like Sony PlayStation being sold at cost price or even lower, but then you have to spend good money on software, movies, accessories and stuff. And I kind of like such an approach.
Back in the days I've bought my 7D twice, while waiting for a good deal on 5D2 :)

Well, I'm not really sure about Sony's attractive pricing... The A7 III is still 2299€ here, with the RX line (is there another bridge camera with the price tag of the RX10 m4?) and even their APS-C line any new camera is more expensive than the previous one. I used to hear Sony makes the best and most expensive TVs, then there was the VAIO, more expensive than anything else. Until Apple was popular again and people wouldn't put 2000€ in a PC anymore.
But, like printer manufacturers, they wanted to sell the hardware (Playstation) very cheap to make money on software. Yet Microsoft is even more aggressive...
Seems to me that they're applying the basic rule: if you have no serious competition, take as much money as possible. If the competition is fierce, sell as much as possible. Also, make your own standard so that people buy only into your products. I have a Sony audio player that is not using standard micro USB and a Sony bluetooth protocol that works only with their headphones...

well, I find it funny because the way I see it Sony is acting exactly like Apple does. Whenever a new iPhone is released, it's more expensive than the previous one and they keep selling older models at high prices. Some of their features are only for the newer models, even though the hardware would allow it on older models.
The high price tag is justified by the unique specs/performance but like the obsession with thinness on Apple side, Sony releases a very fast AF on RX100 V with a price tag above $1000, when that kind of money can buy you a decent camera and a decent lens, with more possibilities.
Finally whenever you ask a Macbook owner, they never had an issue with it, they never heard of anyone having an issue with it, and it makes them feel more productive than anyone else. For no reason would they ever switch to a crappy (A)PC(-S) ! ;)

Lens on RX10 m3 is the same as on m4, the latter having a better AF. It's funny that people are saying, about Fujifilm's firmware upgrades, that they should have released a proper camera from the start but when Sony releases a camera with a frustrating AF (I've used at the zoo, it's tough to follow BiF or fast moving animals. AF also gets stuck in the fence...) they fix it and add an even higher price tag, but everyone's happy with it???

reference:

http://www.opticallimits.com/fuji_x/746-fuji35f14?start=2

http://www.opticallimits.com/sonyalphaff/980-sonyfe50f18?start=2

@ecka84: about the AF stuck in the fence, yes, it's probably asking too much but at least on the E-M1 II the AF locks on the animal, especially if it's moving. No need for a DSLR here but maybe they improved it on RX10 m4, my comment was really for the m3 I own.

You don't have to convince me about Apple. Been there (overheating MBP Pro 2011) done that. Whether or not the quality is actually there is not the point. First, whatever bad experience there are, they are drowned in the mass of blind love. Second, to any regular user their products look easier to use, it's an overall better experience.
But again, Sony is doing the same when designing their products. Whenever you want a new feature, or let's say a menu item, buy the more expensive camera. What? you were happy with A7 but the adapted Canon lenses are not working well? buy the A7 II that has the same AF but the option to force PDAF...
"Just look at those soft and waxy Fuji samples" stop looking at samples and try a camera.

@ecka84: well, the darker one is the Sony A7 II + 16-35mm f4 shot at f8, the brighter one is the Sony A5100 + Sigma 19mm f2.8 shot at f5.6. So DoF and FoV were not perfectly matched, there was no trick intended. I just wanted to show that a $500 combination is not world apparts from a $2000+ combination. If anything, looking at the dust on the bottle that is in focus, it looks sharper on the A5100.
Also exposure-wise, am I losing so much light on the APS-C camera ? the f-stop difference I have inflicted on the FF is making the scene darker (and I should have used f8.4 to match the APS-C f5.6, if it had been possible). I could have compensated by using ISO 200 on the FF but ISO 100 looks ok on the A5100.
So, I'd like to change your "any picture looks better on FF" with "a certain amount of pictures look better on FF".
Whenever I get the time I'll do your "Fuji looks darker because they cheat with ISO" test (although it's been debunked so many times now...).

Didn't say there was an issue with the sharpness on FF shot, I just noticed the dust on the red collar that is in focus was more visible on the APS-C side, for instance. And yes, I could have made the shot with the FE 28mm, making the combination less expensive on the FF side but the point was just to see if any random shot would be magically better with FF.
I don't think there is much point in talking about A5100's lack of features as you said "For me, photography is about the pictures, above everything else". A6000 is only slightly more expensive and I do not own one. I wanted to compare the cheapest, smallest and lightest APS-C combination I do own, and my standard "go to" combination for FF.
Once again, we see that equivalence is an obsession beyond reason: what good would a 10-22f2.5 (or rather 2.6666667 since crop factor is 1.5x) do compared to a 10-22f4? on such a lens we wouldn't care about DoF... compensating for the worse high ISO performance would be the only reason...

Well, I guess you must have loved that DPR article about sensor sizes and the notion of good enough...
That's the thing, "superb" has no meaning either. Some will think superb means scoring highest MTF values in reviews, they rely on numbers and fact, they don't lie. Some will notice that their gear drastically improved their rate of keepers or the perceived IQ, compared to what they previously had. Some will consider a camera that is the best it could be within a set of specifications shared by its peers (I'd nominate RX10 M3/4, Ricoh GR, maybe A7 III...).
And we've been over it a thousand times: larger sensors produce better quality images among the same generation, quality of lens, price range, zoom vs prime, etc... an average lens on FF (and/or old camera) won't 'destroy' a decent combination on APS-C.
And if you've printed 1m wide on APS-C (on a recent camera) and it wasn't good enough, ok. I can't convince you if you made your own observation, only if you speak from theory.

Also a convinced Fuji user(since x100/Pro1 and 2, coming from pro Nikon)Yet..... not long ago in possession of the X e3.(agreed a different type of) And not wishing at all to make the change!

I'm a D500 user and I have the XP2... the D500 is a different beast and it's a pleasure using it. I'll still keep it even if I decide to buy XH1.

Not bad, per se, but definitely a calculated departure from a product strategy that's been very successful for Fujifilm since the 2010 introduction of the X-100.

I realize there are a number of current Fuji shooters who eagerly placed pre-orders for the X-H1 and are now enjoying doing photography the camera. To them I say, "Rock on! Enjoy your new kit." But let's step back and look objectively at where the X-H1 competes in the wider interchangeable lens camera market.

Setting aside current Fuji owners, fill in the blank: "You're likely to switch to/add the X-H1, because the X-H1 offers (blank) that your current camera or another competing camera doesn't." I would argue the X-H1 offers little in the way of compelling design and specs to the photographer who currently shoots with anything other than Fuji.

Let's check back in a year from now to see how well the X-H1 has faired on the open market. If it's a sales leader, I'll need the first to step up and admit I was wrong.

X-H1 small?
I am saying all these big/heavy/expensive sub frame camera is a bad idea

of course not include X-E3

Yep they're pretty small. Bordering on being too small in fact. I have an X pro 2 which is a nice size camera, I had a X-T1 but it was a bit on the small side. I think this X-H1 with a grip you can hold onto will be perfect. The Olympus Em1 series are beautiful cameras but way too small for me. The buttons are hard to tricky to access etc. The Sony A7/9 series obviously have excellent sensors but ergonomically they're a bit of a pain to handle. Everything is relative.

It is a choice. Sensor size is not important for some. Ergonomy, AF, dependability, real weather sealing, good touch screen, smaller and lighter lenses, better IS may be more important for many people.

"smaller and lighter lenses" - BS!

BS? Ecka84, can you actually discuss like decent normal human beings?
I was talking in general, not specific to Fuji system. FF sensor is nice but usually comes with heavy and expensive zoom lenses. Sensor is not always the primary variable when choosing a camera system. There are people happy with RX10 IV, m43, and even Nikon 1 system.

It's been discussed hundreds of times already and yet every time someone brings it up again. Repeating the same old BS endlessly won't make it true.
FF sensor doesn't come with heavy lenses. You have to buy them separately :). And my point is that you don't have to buy the largest, the heaviest and the most expensive optics compatible with your camera. And comparing the largest one from one system vs the largest one from another system, is a silly comparison. Same F-numbers don't make them equal. F4 on FF beats F2.8 on Fuji, period. So, please, learn the equivalence principle and stop the BS.

BS! f/4 from FF won't beat f/2.8 from Fuji.

Equivalence can be made either on shallow DOF or on exposure. F-number is F-number. Frankly, you even get more DR on Fuji X-T2 with 56/1.2 at ISO200 f/1.2, 1/500s, than with Sony A7r3 with 85/1.8 at ISO 500, f/2, 1/500s. BOOM! Facts!

Or you can match the DR and get faster shutter speed on Fuji. BOOMBOOM! More facts!

Or you can turn it around and consider that what do you need to carry to shoot portraits with at least DOF of 25cm? Or a landscape with 24mm equivalent FOV and DOF of infinity? BOOMBOOMBOOM! Even more facts!

I think buying a Sony, or at least licking the Sony spec sheet really makes people stupid.

Sorry for the rest of you. That level ignorance just requires special kind of attention.

Sensor size is one of the factor to consider when choosing a camera. It's not the only factor, nor the ultimate factor.

@taktak91
So, is it OK if your employer pays you only half of the amount you've been promised for the job? While telling you stories like "money doesn't matter, it's not the most important factor, blah, blah, blah ...". Because APS-C is more than twice smaller than FF and it shows in the actual images. Unless they are both too much for you, which suggests a question - Why are you arguing if you don't care to see the difference?

OK. I give you a challenge. You will need to go take following pictures:
1) A close portrait, native ISO, flash lighting, DOF from nose tip to the ears
2) A 20mm FOV f/16 landscape, native ISO
3) A f/2.8 shot of a running kid, as fast shutter speed as possible.

Now, if made "equivalent" kits, you will
1) get much lighter gear bag with APS-C / MFT than FF
2) get (in general) cheaper gear with APS-C / MFT than FF
3) get slightly better 1:1 pixel level image quality in terms of noise on FF, if you stick to same megapixel amount.

These are facts, not fairy tales, facts. 1) and 3) are dictated by laws of physics and also by the advancements in sensor technologies, which have dragged MFT and APS-C sensors very close to FF sensors (as FF sensors have since D800 pretty much hit their physical limits, with BSI + dual gain giving a slight boost).

Only where FF will be clearly beneficial is that it will be 1-1.5 steps further usable on high ISOs than APS-C, and allow higher megapixel counts.