XF56 f1.2 released and specs

Started Jan 6, 2014 | Discussions
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brandagnostickk
brandagnostickk Junior Member • Posts: 27
envy is what comes to my mind for this lens

I own several brand DSLRs but I have to say this lens looks good enough to entice me (more) to think about a mirroless venture.

Krich13 Contributing Member • Posts: 619
Re: XF56 f1.2 released and specs

nalax wrote:

Let us know how much to change for our 4x5 or 8x10 cameras. Would a banquet camera require more of your "proper" exposure? How about one of Maxwell Smart's spy cameras? Exposure is exposure, buddy.

I hope to see more of the 56mm, hopefully soon!

Krich13 wrote:

ISO must remain the same for the the comparison.

Huh? Why is that? For proper comparison ISO of the FF should be icnreased (compared to APS-C) by a stop and a little, and aperture set to its DOF-equivalent value. Shutter speed the same.

You really don't understand. For film, yes, you need exposure per unit area. For semiconductor sensors the relevant parameter is total amount of light captured by the entire sensor.

Especially for you, I copy my post over again:

________________________________________________________________________

Depends how you define "exposure". In the old film days, it was indeed "exposure PER UNIT AREA" regardless of frame size. Deliver too few photons, and the film is underexposed, milky what not. Deliver too many, chemical changes facilitate turning the entire frame black.

For semiconductor sensors what matters is the total number of photons per photosite, pretty much regardless of the site area. Make two sensors: say an APS-S and FF ones both of say 16 megapixels. Expose them using the same scene for the same duration using 56/1.2 and 85/1.8 lenses respectively. Each photosite will receive the same NUMBER of photons (the number per unit area is 2.25 times larger in the first case, but the area itself is smaller by the same factor). Each photosite (given equal quantum efficiency) will produce the same number of electron-hole pairs (photocurrrent) ergo the same signal and the same shot noise. If you read each sensor with the same preamplifier, equal Read noise will be introduced in both cases, as would be required amplifier gain!

However, a Photomertist would assign the first case say ISO 100, and the second -- ISO 225 based on exposure PER UNIT AREA, even though the physical amplifier gain is exactly the same in both cases.

The origin of your confusion is extrapolation of ISO sensitivity concept to modern sensors -- irrelevant one for digital sensors, the proper metric would be "light delivered to the whole sensor")

Martin Datzinger Senior Member • Posts: 2,222
Aperture ring

I'm pretty much on a decission here because I'd like to invest in a kit prime lenses and I have yet to decide which system. I have a D600 with the 2.8 zooms as workhorses. From the primes I want to have a decidedly different shooting experience. So it may very well become the Fuji with 23/1.4, 35/1.4 and a 90/2 they'll hopefully release someday (but sadly not before 2016, according to the roadmap - why they'll rather stick to big tele zooms I don't know).

Or I chicken and invest on Sigma, the 35 already being excellent, the 50 was announced yesterday and a 135 is very much on the horizon.

But honestly the Fuji route is somehow more tempting, a system more around what I'd expect from prime lens shooting. Aperture rings and stuff. But there is the issue, the XF primes' aperture rings until now looked very floppy to me. So I very much welcome that the 56's announcement states "The aperture ring is designed to ensure it’s easy to detect ‘clicks’ between f-stops"

I guess that stems from user feedback, a thing Fuji is very much known to take serious. So do you think they'll facelift the existing lenses for a stiffer aperture ring? IMO they could go from 1/3 to 1/2 stop detents at the same time, but a ring that can't be turned by the tip of the small finger or by accident would be nice enough for me.

Best regards,

Martin

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malcolml1 Regular Member • Posts: 216
Re: XF56 f1.2 released and specs

Ok - in the second question I actually forgot to say that I meant the same number of pixels (though I realize this would result in a lot of dead space on the sensor - it was a hypothetical question).

Now I've thought a bit more, I think there is another source of confusion....I have convinced myself again that, whilst I accept that noise levels would be different, if I took a photo with my Fuji and the 56/1.2 at ISO200 and did the same with my (now sold) 5D mk2 with the 85/1.2 at ISO 200, both in aperture priority mode, they would both select much the same shutter speed (I assumed that both Canon and Fuji agree on definition of ISO).

To you (I think) equivalence also includes achieving equivalent noise levels. Pixels are buckets for collecting photons and converting them into electron-hole pairs (as you said). Obviously a bigger bucked can collect more photons (and generate more electron hole pairs). But then the actual number of electron-hole pairs is not used to form the image - rather the signal is digitized when it is read. If both the APS and FF sensor are 14 bit, then in underlying analog signal is converted into one of 2 ** 14 levels. Further, I assume that the levels (at base ISO or amplification) are spread (non-linearly, I know) between 0 and 'full' (max electron-hole pair capacity for that pixel).

To me, a given exposure would result in of the same output level regardless of sensor format - I think this is because the supposedly common definition of ISO.

The advantage of a larger pixel size is the confidence level you have in the level you measure after conversion. More exactly (I work with statistics...), you would be confident that if you repeated the measurement with 10 different pixels they would report the same level for that actual exposure. For example, a uniform area of blue sky - with bigger pixels, you have much more confidence that adjacent pixels would measure the same level after conversion to digital. You have less confidence with smaller pixels - and in fact this lower confidence manifests itself in adjacent pixels reporting more variation in the level they measure. We see this as noise.

Even simpler example - if the read error (I think this is what it is called) is + or - 10 electron-hole pairs for both APS and FF sized pixels, and the APS pixel has a maximum capacity of 100 vs the FF pixel of 1,000 (making the numbers up for illustration), then the likelihood of the analog signal being converted to exactly the same level in the blue sky example is lower for the APS sensor (+ or - 10 out of a total number of 100 is a much bigger error than + - 10 out of 100).

a l b e r t OP Senior Member • Posts: 1,434
Re: XF56 f1.2 released and specs

malcolml1 wrote:

Ok - in the second question I actually forgot to say that I meant the same number of pixels (though I realize this would result in a lot of dead space on the sensor - it was a hypothetical question).

Now I've thought a bit more, I think there is another source of confusion....I have convinced myself again that, whilst I accept that noise levels would be different, if I took a photo with my Fuji and the 56/1.2 at ISO200 and did the same with my (now sold) 5D mk2 with the 85/1.2 at ISO 200, both in aperture priority mode, they would both select much the same shutter speed (I assumed that both Canon and Fuji agree on definition of ISO).

To you (I think) equivalence also includes achieving equivalent noise levels. Pixels are buckets for collecting photons and converting them into electron-hole pairs (as you said). Obviously a bigger bucked can collect more photons (and generate more electron hole pairs). But then the actual number of electron-hole pairs is not used to form the image - rather the signal is digitized when it is read. If both the APS and FF sensor are 14 bit, then in underlying analog signal is converted into one of 2 ** 14 levels. Further, I assume that the levels (at base ISO or amplification) are spread (non-linearly, I know) between 0 and 'full' (max electron-hole pair capacity for that pixel).

To me, a given exposure would result in of the same output level regardless of sensor format - I think this is because the supposedly common definition of ISO.

The advantage of a larger pixel size is the confidence level you have in the level you measure after conversion. More exactly (I work with statistics...), you would be confident that if you repeated the measurement with 10 different pixels they would report the same level for that actual exposure. For example, a uniform area of blue sky - with bigger pixels, you have much more confidence that adjacent pixels would measure the same level after conversion to digital. You have less confidence with smaller pixels - and in fact this lower confidence manifests itself in adjacent pixels reporting more variation in the level they measure. We see this as noise.

Even simpler example - if the read error (I think this is what it is called) is + or - 10 electron-hole pairs for both APS and FF sized pixels, and the APS pixel has a maximum capacity of 100 vs the FF pixel of 1,000 (making the numbers up for illustration), then the likelihood of the analog signal being converted to exactly the same level in the blue sky example is lower for the APS sensor (+ or - 10 out of a total number of 100 is a much bigger error than + - 10 out of 100).

The comparison of APS-C sensor and FF sensor is a complicated one. It is because the sensor performance from one generation to the next can be very different.

For example, the high ISO performance of the X-Trans CMOS I sensor is on the same level of the FF sensor in 5D2, even though the sensor is 2.25x larger.

Moving along to the sensor in 5D3, high ISO noise is much lower. So when one has to compare, the comparison needs to be made to roughly the same generation sensor.

Then there is the number of pixels on the sensor. If you have a 36MPix sensor such as the one in D800, the pixel size is the same as the pixel size of a 16MPix sensor. It is because 36 / 2.25 = 16. So the number of pixels within an APS-C crop of D800 sensor is the same of that of a X-Trans sensor.

Since pixel size is the same, and the D800 sensor is roughly the same generation as X-Trans I, the quantum efficiency of the two sensors should roughly be the same.

Yet if you examine at the pixel level, you'll see that the noise of a 36MPix D800 sensor is actually noisier than the X-Trans I even at ISO 1600. I believe having two extra green pixels in a 6x6 grid helps lower the luminance noise.

Now if you compare to the next generation 36MPix sensor in A7r, you'll see that the high ISO noise is comparable to the X-Trans CMOS II.

Another reason why full frame sensor appears to have lower noise when viewed on the screen is due to pixel binning. You scaled down a 36MPix sensor to fit in your 3MPix screen. It is going to look better than a 16MPix sensor scaled down to 3MPix, both in terms of noise and details.

So all it boils down to is how large of a print are you going to make. It is not going to make a whole lot of difference even if you print it as 16x20.

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malcolml1 Regular Member • Posts: 216
Re: XF56 f1.2 released and specs

Hi Albert,

I totally agree that things are complicated when comparing noise capabilities across different generations of sensor. And also that up to a certain size print no one really cares (I even remember shooting 1600 ISO film that looks noisier than my X-Pro or XE-2 at 6400 even on a 7 x 5 print!).

So my question to you is.....assuming I am not making huge prints and don't care about the small amount of noise difference, if I set the 5d mk3 to ISO 200, with the 85/1.2 lens, and take the identical image with the XE-2 and 56/1.2 also at ISO 200 (position adjusted to give the same image), how would the exposure time differ between the two (assuming that Canon and Fuji have the same definition of ISO - i know that isn't the case, but I want to understand the ideal case before the more complicated reality)

Malcolm

bigpigbig Senior Member • Posts: 1,721
Re: XF56 f1.2 released and specs

malcolml1 wrote:

Hi Albert,

I totally agree that things are complicated when comparing noise capabilities across different generations of sensor. And also that up to a certain size print no one really cares (I even remember shooting 1600 ISO film that looks noisier than my X-Pro or XE-2 at 6400 even on a 7 x 5 print!).

So my question to you is.....assuming I am not making huge prints and don't care about the small amount of noise difference, if I set the 5d mk3 to ISO 200, with the 85/1.2 lens, and take the identical image with the XE-2 and 56/1.2 also at ISO 200 (position adjusted to give the same image), how would the exposure time differ between the two (assuming that Canon and Fuji have the same definition of ISO - i know that isn't the case, but I want to understand the ideal case before the more complicated reality)

Malcolm

Why make it so complicated.

Same Aperture + Same ISO = Same Shutter speed. PERIOD.

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Bernie Ess Veteran Member • Posts: 7,001
Re: Aperture ring

Martin Datzinger wrote:

But honestly the Fuji route is somehow more tempting, a system more around what I'd expect from prime lens shooting. Aperture rings and stuff. But there is the issue, the XF primes' aperture rings until now looked very floppy to me. So I very much welcome that the 56's announcement states "The aperture ring is designed to ensure it’s easy to detect ‘clicks’ between f-stops"

I use the X-E1 since a year or so, and I like the lenses I currently have (27/35/18-55/55-200), but I really think I'd easily switch to aperture via thumb wheel (camera backside, upper left side) if Fuji made it available via firmware to control the aperture in both ways.

I do it on my tiny and extremely sharp 27mm pancake, I did it for years on my DSLRs, in my opinion it requires less effort and concentration than turning an aperture ring. I never had an issue with the operation of any of the rings (easy, medium, hard), except for the fact that it always is less automatic than turning that small thumb wheel.

As for the system question: You say the Fuji system is better around what you'd expect from prime lens shooting: There is of course the weight of the kit that is much lower than the Nikon/ Sigma. However the FF kit gives you better DOF control with all of the classic primes (35mm, 50mm - annonced - 85mm) and the quality of all recent Sigma Art lenses has apparently been breathtaking. More than anything anybody thought Sigma could do even 1-2 years ago. Add a 135, a 85mm/ Mk II  and maybe a 24mm and Sigma may have the highest quality set of all manufactuers.

For me the main issues are weight and the Fuji look that I really like. Although not quite up to the old Fuji DSLRs, I still think Fujis have better colours than Canon and Nikon. I never came to like the ook of the Nikon files, regardless of profiles and Raw converter.

I am also hesitating to buy those expensive Fuji lenses rather than going dual with Fuji (for lightweight shooting) and Canon FF for the rest. I may wait for the 50mm Art lens, the Sigma 35/1,4 already looks stellar.

Bernhard

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malcolml1 Regular Member • Posts: 216
Re: XF56 f1.2 released and specs

Yes - exactly - that's what I believe too. but some others argue differently.....and I am trying to understand why!

bigpigbig Senior Member • Posts: 1,721
Re: XF56 f1.2 released and specs

malcolml1 wrote:

Yes - exactly - that's what I believe too. but some others argue differently.....and I am trying to understand why!

They are either misinformed or making an necessary conversion from actual ISO to some hypothetical equivalent ISO.

Light meters have no input for sensor size or film size. I can shoot ISO 100 35mm film or an 8x10 sheet of ISO 100 film and if the same aperture is used then the same shutter speed will be required for an equivalent exposure.

Will more "total light" reach the 8x10 film sheet, of course. But it is irrelevant to the exposure (tone). Will more detail be captured by the 8x10 sheet, of course. But it will have the same exposure (tone).

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Ross Kennedy Regular Member • Posts: 300
Re: Aperture ring

Martin Datzinger wrote:

But there is the issue, the XF primes' aperture rings until now looked very floppy to me. So I very much welcome that the 56's announcement states "The aperture ring is designed to ensure it’s easy to detect ‘clicks’ between f-stops"

I guess that stems from user feedback, a thing Fuji is very much known to take serious. So do you think they'll facelift the existing lenses for a stiffer aperture ring? IMO they could go from 1/3 to 1/2 stop detents at the same time, but a ring that can't be turned by the tip of the small finger or by accident would be nice enough for me.

Best regards,

Martin

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I've had the 14/18/35/60 for a long time and loose aperture rings really aren't a problem in real-life use. I always check the aperure dial setting as I raise the camera to my eye and you can constantly check the setting in the OVF/EVF while you take pictures, so I rarely mess up a photo due to an incorrect aperture setting.

Bernie Ess Veteran Member • Posts: 7,001
Aperture is electronically coupled anyway...

I forgot that as far as I know, the aperture ring is a pure "mockup", it just controls the aperture electronically, not mechanically. Just like the Manual focus on these cameras is not direct, but focus by wire. I hardly ever used it.

As aperture is electronically coupled, control via thumb wouldbe the more logic choice anyway.

At least in my opinion. The lens ring is pure nostalgia without necessity, inlike on the older lenses where the ring really changed something.

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brandagnostickk
brandagnostickk Junior Member • Posts: 27
any more info on the lens?

any links somewhere?

Krich13 Contributing Member • Posts: 619
Re: XF56 f1.2 released and specs

malcolml1 wrote:

Now I've thought a bit more, I think there is another source of confusion....I have convinced myself again that, whilst I accept that noise levels would be different, if I took a photo with my Fuji and the 56/1.2 at ISO200 and did the same with my (now sold) 5D mk2 with the 85/1.2 at ISO 200, both in aperture priority mode, they would both select much the same shutter speed (I assumed that both Canon and Fuji agree on definition of ISO).

At the same ISO, yes. But why would you select the same ISO in the first place?If your shot requires (for your artistic or technical purposes) certain DOF, or certain shutter speed, or certain noise level -- you are free to play with remaining parameters at will.

In case of equivalent apertures (say f/1.2 on APS-C and f/1.8 on FF) selecting ISO 1 1/3 stops higher for an FF would result in the _same_ DOF, noise and shutter speed. The only reason to avoid raising the ISO are either noise concerns (not a concern, the noise is the same in both  cases) or shutter speed (say if you want to avoid to fast a shutter to allow some motion blur) -- again not a concern for the shutter speed is the same in both cases.

But then the actual number of electron-hole pairs is not used to form the image - rather the signal is digitized when it is read. If both the APS and FF sensor are 14 bit, then in underlying analog signal is converted into one of 2 ** 14 levels. Further, I assume that the levels (at base ISO or amplification) are spread (non-linearly, I know) between 0 and 'full' (max electron-hole pair capacity for that pixel).

I am not sure what you are trying to say here. Let's consider the example of the same pixel count again. FF photosites 2.25 times bigger. Apertures 1.2 and 1.8 for APS-C and FF respectively. Same illumination of the scene, same shutter speed.

Result: Same number of electron-hole pairs in both cases -- ergo the same signal and shot noise levels. The same amplifier gain is required (though the ISO convention would assign 1 1/3 stop higher ISO rating to the FF case -- but the amplifier and analog-to-digital converters do not know anything about ISO convention -- nor would they care if they did).

At what point of recording, reading or digitization process would the results (signal, noise, bit resolution, dynamic range -- whatever comes to your mind) become any different in these two cases?

To me, a given exposure would result in of the same output level regardless of sensor format - I think this is because the supposedly common definition of ISO.

I really don't understand this passage. Electronics knows nothing about ISO, and any sane manufacturer would squeeze as much signal-to-noise ratio as possible at every setting, whether it is base ISO, elevated or however it's defined. ISO is an empty number assigned to real settings (such as amplifier gain) afterwards.

The advantage of a larger pixel size is the confidence level you have in the level you measure after conversion. More exactly (I work with statistics...),

Great. If you work with statistics you know what Shot noise is, and why it's the same in both cases.

a l b e r t OP Senior Member • Posts: 1,434
Re: XF56 f1.2 released and specs

malcolml1 wrote:

Yes - exactly - that's what I believe too. but some others argue differently.....and I am trying to understand why!

As bigpigpig has stated, the shutter speed would be the same, assuming they have the same metering.  Personally, I found that Fuji's metering is different than Canon, it tends to expose the scene brighter, perhaps due to having more DR in the sensor.

As a side note: people said Fuji's ISO is inflated.  But that is due to the metering.  Fuji exposes brighter, so higher ISO is used.  They should check the histogram before they declare Fuji having inflated ISO.

People are confused by the FF lens gathering more light because it covers a larger image circle.  Yes it gathers more light, BUT the light also needs to be spread out in a larger surface area.  So the amount of light intensity per unit area on FF is the same as APS-C.  This is why the same aperture on FF = APS-C = camera phone.

However, lens FOV is different with different sensor size.  This is why manufacturers use 85mm on FF, but 56mm on APS-C.  This conversion is correct.  But you don't see them converting f-stop from a FF lens to a different value on an APS-C lens, right?  This already tells you f-stop is the same (exposure OR light intensity per unit area), regardless of sensor size.

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Martin Datzinger Senior Member • Posts: 2,222
Re: Aperture ring

Well and exactly that is absolutely against my shooting habbits and my idea of something being "manual". I already hate all of my Nikons' back wheels for that reason: They are far too easily turned by accident because they are too close to the tumb. Camera orientation change -> wheel barely touched -> camera went from x-synch to Bulb -> shot ruined. Happend all too often to me. So I do want dedication and a little bit of concentration necessary to change aperture. I don't know anyone who changes aperture between each and every shot and the choice of the aperture alone is something that requires a thought process, so why make accoding dial that easy to operate (note: I still believe this is the more intuitive place to do it, rather than a thumb wheel).

I'm certain they changed the force needed to turn the aperture because of feedback, they are known to take user opinions seriously. Hence my hope they retrofit the older ones (quietly).

Best regards,
Martin

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malcolml1 Regular Member • Posts: 216
Re: XF56 f1.2 released and specs

Totally agree. Some people extend the idea of equivalence to include the noise characteristics of the resultant image. FF has a slight advantage here, so similar noise characteristics are achieved by increasing the ISO (which means you need to stop the lens down accordingly).

However, I personally believe that this argument more theoretical than practical with modern sensors, since noise levels are so low. I'd be surprised if anyone can tell the difference between two properly exposed prints - one shot at 200 and one at 800 or even 1600 ISO.

So for all practical purposes I would say that the new Fuji 56/1.2 on APS is 'equivalent' to an 85/1.8 on FF as far as DoF and angle of view are concerned, and equivalent to an 85/1.2 on FF as far as shutter speed at a fixed ISO are concerned. As the end user that's all I care about.

Within reason, I do not care about noise now - different story 10 years ago. I remember accidentally leaving my Canon 10D set on ISO 800 whilst shooting a car blaze in the middle of a busy London street. In broad daylight and the images were horrible. With my Xe-2 or X-Pro1 it doesn't matter (to me).

Cheers,

Malcolm

The Davinator
The Davinator Forum Pro • Posts: 16,606
Re: XF56 f1.2 released and specs
2

Bernie Ess wrote:

I shoot only RAW and without a single doubt Nikon is the better system for this IMO with the Fuji being the worst, skin tones are inconsistant and often horrid from the Fuji X, now if Fuji dropped the X sensor then things might well be different.

Then you may do something wrong. Do you have some "horrid samples" from the Fuji X online somewhere? I'd be curious to see them.

Colour engine of the d800 is a bit less unpleasant than older Nikon models, but still not up to Canon or Fuji.

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Bernie....he just trolls the Fuji forums complaining Bout color, bokeh, etc.  Just ignore him....he's looking for an audience to support his bitter pill.

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dotborg Veteran Member • Posts: 8,250
Re: XF56 f1.2 released and specs

dark13star wrote:

Krich13 wrote:

No, you can use the same shutter speed, adjusting ISO accordingly for the same Image quality results.

Maybe on a Nikon FF, but have you seen how many Canon shooters here say they get better high-ISO results out of their Fujis? ISO must remain the same for the the comparison.

Raw files from my 5D Mark II produce less total noise than the raw files from my Fujifilm X-E1 and X-E2, and the 5D Mark II is more than 5 years old.

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