Thanks for the reply. I always thought f-stop values are absolute values. Making the communication and thinking easier.

So with same shutter speed. Sony's RX100 will have more light on its sensor at f1,8, than Panasonic LX7's at f1.4.

Yes it is the combination of ISO and sensor area that determines the image quality, not ISO on its own. The RX100 sensor collects roughly the same amount of light at ISO 350 as the LX7's active sensor area does at ISO 100.

Well said.
Personally, I won't be buying any new compact camera with a sensor smaller than m4/3.

http://www.dpreview.com/learn/?/key=sensor%20sizes

That would have been my problem too - otherwise I think it's a slightly better camera than the Olympus XZ-1. However, the X10 wasn't even available last summer when I got the XZ-1.

The XZ-1 just manages to fit inside a common Sony case, which then just fits in my front pocket. It's perfect for going to the amusement park or any place I don't want to carry my DSLR around, yet still want flexibility and good quality RAW photos.

Between the XZ-1 and the iPad2 it's possible to travel light on trips without sacrificing too much functionality.

1. Don't you just love the marketing spin they put on it? As if using a tiny sensor "allows them" to use a brighter lens... as if that is a limitation!

2. You are right... Panasonic takes a crop, making the effective used sensor area even smaller!
They use a 13mp sensor, and take a 4:3 or 16:9, 10MP crop out of it. SAD.

An F1.4 lens on 1x0.75mm sensor would also be able to capture with the same shutter speed at the same ISO, does that mean you would be satisfied with the quality it will provide? Maybe they should start selling F0.9 lens cameras on sensors this size, it seems like it will be a success.

How can you not understand that ISO 1600 on the LX7 does not equal ISO 1600 on the RX100.
This is just so obvious...

@Timmbits, sorry i have to disagree with you here, i like your charts though! :)

It is the size of the equivalent aperture that determines the size optics so using a 9x6 sensor for example allows using a 7mm F/1.4 lens that is about the same size as a 28mm F/5.6 lens on 36x24mm sensor, note that i am talking about the size of the actual optics, the barrel extension would of course be different, but i do take this into account when suggesting what size sensor they should use for a given lens spec in a given camera size.

And also i actually want manufacturers to put oversized sensors in camera's to allow for multiple aspect ratio's to use the full lens image circle, i do not want this to be used to deceive people with fake specs though :)
So in the full frame camera i want i actually want a 37.71x25.96mm sensor to allow every aspect ratio from 4:3 to 16:9 to use the full lens image circle diameter.

How can you not understand that ISO 1600 on the LX7 does not equal ISO 1600 on the RX100.
This is just so obvious...

The manufacturers should really just start making 3x2mm sensor compacts with F1 lenses.
What the hell are they thinking making aps-c or even full frame camera's!?

28mm F2.8 is the lens i want most for a full frame compact interchangeable lens camera.
I am not sure what you mean by F1.4 exactly? On which sensor size? The number is meaningless on its own.

I agree, i also would prefer a compact with a prime lens over one with a zoom lens.

A camera the size of the Sony RX100 can be made with an m43 sensor and 14mm F1.4 lens.

Of course as i said before i would much prefer a full frame sensor with 28mm F2.8 lens which would retract to about the same thickness, only the barrel extension mechanism would be larger though i estimate it would still only extend about half the length as the zoom lens on the RX100 does so i consider this insignificant, the sensor size itself is also insignificant compared to the size of the camera so it also would add very little to the total size.

malcolm, on a 4x3mm consumer camera, resolution isn't as important as noise to the general public. They want pictures that look good when resized to fit a screen. That means all they really need are 3MP of un-smeared, un-watercolor-looking detail. Give those people a camera that can use ISO 400 instead of 1600 and they'll be happy with the results.

Yaa sure , using any camera before LX7 is frustrating.

That doesn't mean I'm not making photos, Howabout - I most assuredly am. It just means I can't yet purchase the combination of features, technology and physical packaging I want, at a price I'm willing to pay.

Love your screen name, by the way.

I did not say anything about low light noise performance did I? An F4-7 16-60mm zoom lens on 24x16mm sensor would have about the same aperture size throughout the zoom range which is exactly the point i was making.
The difference would be that the lens on aps-c would deliver at least double the resolution wide open at F4 than this crappy F1.4 lens, or in other words provide 4x the amount of pixels worth of resolution.

I am quite confused about the lack of interest in this topic. Why do people care to buy quality lenses for interchangeable lens camera's if they dont care about the resolution the lens provides?

Sensor size is a huge factor in the optical design for a lens of a given field of view and aperture diameter since resolution limited by optical aberrations scales directly with the F number.
Combined with the effect of diffraction, tripling the sensor size for this particular lens spec will roughly double the resolution at an aperture setting somewhere between the largest of the wide and tele end.

What is your point? I know there are two interpretations which is why i said both that it would double the resolution and added that this would be worth 4 times the amount of pixels.

Besides is that all you have to comment about after these posts? I dont see how it is relevant to the discussion.

Care to explain what you are talking about? Are you unaware that lenses have a limited resolution? It is not only the sensor pixel resolution that matters...
You are really not making any sense at all with these arrogant replies.

http://en.wikipedia.org/wiki/Resolution
Maybe you should read this, no i was not talking about a new years resolution.
The fourth under measurement resolution:
http://en.wikipedia.org/wiki/Optical_resolution

Mal82:

What you may mean is that a lens will diffract light in a manor that higher density sensors can't keep up with. But that doesn't really apply here. No matter how valid the WikiMath you cite. The lens on this Panasonic will resolve really well. The the quanta of light will hit those Panasonic holes.

So in other words the resolution of the 12MP Samsung EX2 is the same as that of the 12MP Nikon D3s, independent of the lens. Now the Nikon with its lower pixel density will do high ISO and dynamic range better than the Samsung no matter what lens is mounted on the Nikon--but those qualities aren't resolution even though they do allow for bigger prints from the Nikon files. Now Nikon lenses distort reds at high ISOs and one way to get around this is to use a better Zeiss lens, but that's still not a resolution thing.

Remember you're the person who started out with the laughable claim about this LeicaPana lens being a "horrible" lens. So your claims aren't real valid.

Have you actually compared the quality of a prime lens at F1.4 compared to that or another prime lens at F5.6? Why do you think lenses need to be stopped down? Optical aberrations are horrible at F1.4

Just look at this review:
http://www.dpreview.com/lensreviews/canon_50_1p4_c16/5

A 150mm F4.2 lens on 108x72mm sensor at F4.2 would have optical aberrations the same size as the canon 50mm at F4.2, by this i mean the size of the blur spot compared to the total image meaning 3x larger blur spot on a sensor 3x the size. Of course this 150mm F4.2 lens at F4.2 has only the same effect of diffraction on image resolution as the canon 50mm at F1.4.
What this means is that the 150mm F4.2 lens wide open would have significantly higher resolution than the canon 50mm F1.4 stopped down to F4.2. And if you put them at the same actual aperture size of 1.4 and 4.2 the difference will be huge.

In conclusion: larger apertures: GOOD, small F-numbers: BAD
--> We need larger sensors to have larger apertures at higher F-numbers.

malcolm82:

All you've done is explain why good sharp F1.4 lenses are more expensive than sharp F4.0 lenses--not news.

That's one reason people are willing to pay for a sharp when wide open F1.4 Fuji 35mm or Leica F1.4 50mm.

You've confused specific lens sharpness with general resolution rules.

This PanaLeica is likely to be sharp when wide open, albeit with some vignetting.

An example from full frame lenses: the 1.4 85mm manual
Zeiss is incredibly sharp wide open while the 1.4 50mm manual Zeiss is not as sharp wide open, still doesn't say much about resolution just how sharp edges will be.

"All you've done is explain why good sharp F1.4 lenses are more expensive than sharp F4.0 lenses--not news."

This is simply the mathematics of lens design, it does not even have anything to do with manufacturing accuracy.

With two lenses of an equal level of optical design the larger F-number lens on larger sensor will always be superior to an equivalent smaller F-number lens on smaller sensor, why would you assume the lens on a smaller sensor would get a superior optical design for free? Why would you arbitrarily limit the larger sensor lens to be of an inferior design? It does not make any sense. Whatever level design you choose you will get better results on a larger sensor, it is that simple.

"That's one reason people are willing to pay for a sharp when wide open F1.4 Fuji 35mm or Leica F1.4 50mm."

http://us.leica-camera.com/photography/m_system/lenses/

These are leica's own numbers! Compare the resolution charts of the 50mm F0.95, F1.4, F2 and F2.5 lenses. You will see they get progressively better at higher F-numbers, in fact the F0.95 and F1.4 lenses stopped down to F5.6 have similar resolution as the F2 and F2.5 lenses also stopped down to F5.6 which proves that the optical design of the larger lenses is in no way superior to that of the small ones.

It is not the fact that you stop down a lens that increases its resolution but simply the fact that you are using a larger F-number which results in smaller chromatic aberrations which is why the F2.5 lens wide open will achieve similar resolution to the F0.95 lens stopped down to F2.5.

Their 50mm F2 ASPH is a real example of a superior optical design, wide open it roughly equals the resolution of the other lenses stopped down to F5.6 but you can see it still improves a lot when stopping down and if they made a lens design of equal quality with a maximum aperture of F1.4 the resolution would drop dramatically wide open.
You can also see that this lens is significantly larger than the other F2 lens, which is a necessary trade off that comes with a superior optical design. You can see the same trade off with the 21mm F3.4 and 24mm F3.8, both are significantly sharper than the 21mm and 24mm F1.4 lenses at equal apertures while obviously being very large lenses for the maximum aperture size they offer.

"All you've done is explain why good sharp F1.4 lenses are more expensive than sharp F4.0 lenses--not news."

Actually the main reason for the higher price of the F1.4 lenses is simply because they are much bigger, an F1.4 lens on 2.8x crop sensor would be only about the same size as the full frame F4.0 and hence should cost about the same. It is size not F-stop that determines cost.

Mal82--

Those Leica data sheets say "resolution of finer detail". That aint exactly the same as the sensor resolution in combination claims you've been posting.

I never disputed that some lens are sharper.

Stop making up claims to fit your point.

Your original point was that this LeicaPana lens is "horrible" and won't resolve thing well. This remains laughable.

"Those Leica data sheets say "resolution of finer detail". That aint exactly the same as the sensor resolution in combination claims you've been posting."

You obviously dont understand mtf graphs, its simply how they are describing that they are plotting mtf values for different linepair frequencies. Dpreview plots the frequency at a fixed 50% mtf value instead.

What do you mean by sensor resolution in combination? I did not say anything about sensor resolution. Obviously if your lens provides more resolution then you can use a sensor with more pixels to take advantage of it, or the lens wont have to be stopped down to half its maximum aperture to take advantage of a given sensor resolution as is surely the case with this LX7.

"I never disputed that some lens are sharper.

Stop making up claims to fit your point."

How can you argue against the fact that larger sensor camera's have more resolution anyways? It is blatantly obvious. I am not making up anything.

"Your original point was that this LeicaPana lens is "horrible" and won't resolve thing well. This remains laughable."

Have you seen how F1.4 primes perform? Try to figure out what the mtf graphs mean and you might get a clue.

I said : again with a horrible F1.4 lens meaning all F1.4 lenses in general are horrible, it is simply a poor design choice based on marketing to the misguided fixation many people have on low F-numbers, marketing is the one and only reason that this camera comes with a tiny sensor and an F1.4 lens.

malcolm82:

The F1.4 Zeiss 85mm is very sharp wide open. As is the Leica F1.4 50mm. And the new Fuji 35mm F1.4. All of those are extraordinary lenses.

You made a preposterous clam about this PanaLeica, and now you've made a preposterous claim about 1.4 lenses generally--that both very good ones and lower quality ones are sharper, say at F5.6, I don't dispute. But that's not what you said.

You most certainly did make claims about sensor resolution and what sensor size would be appropriate for this camera.

"that both very good ones and lower quality ones are sharper, say at F5.6, I don't dispute. But that's not what you said."

This is exactly my point, the fact that lenses at F1.4 are significantly less sharp than stopped down to F5.6 is exactly the reason why a lens for a larger sensor will offer significantly higher resolution at the same aperture size.

Compare the reviews of m43 and aps-c lenses to the full frame lenses on this site.
Also compare the mtf graphs of the leica lenses to these:
http://www.rodenstock-photo.com/mediabase/original/e_Rodenstock_Analog_Lenses_27-42__8226.pdf
For example, the 150mm f/5.6 lens can be compared to the leica 35mm f/1.4 lens.
Just cut the graph to about 84mm for image height of the large format lens to compare to the 21mm image height of the leica graphs. You can see that the large format lens at F/11 has better mtf values at 20lp/mm than the leica lens F/2.8 values at 40lp/mm. This means that the large format lens has over twice the image resolution as the full frame lens has at that aperture.

"You most certainly did make claims about sensor resolution and what sensor size would be appropriate for this camera."

That is how you interpreted what i said, i actually said nothing about sensor resolution, all i said was that the equivalent lens on a larger sensor will offer higher resolution which is especially true wide open, wether or not they should use a higher pixel count on that larger sensor to better take advantage of the higher resolution from the lens is a separate issue.

I do know that a super quality lens on the LX7 sensor will equal or better a very low quality lens on aps-c but it will also be significantly larger and more expensive to do so which is why i cant really see the point in that. If you are going to invest in a high quality lens then why would you waste it by sabotaging it's resolution by making it for a small sensor?

Note that the rodenstock 150mm F/5.6 lens is actually smaller and lighter than the leica 35mm F/1.4 lens.

Of course it has to be positioned much further away from the film and it is exactly that distance i use to estimate what the largest sensor size is that can be used with a sensible retractable barrel size for a given lens spec.

http://forums.dpreview.com/forums/read.asp?forum=1018&message=42068016

The problem with your entire argument is summed up nicely by something you posted a few hours ago as yet another reaction to my point, quoting you:

"I do know that a super quality lens on the LX7 sensor will equal or better a very low quality lens on aps-c but it will also be significantly larger and more expensive to do so which is why i cant really see the point in that. If you are going to invest in a high quality lens then why would you waste it by sabotaging it's resolution by making it for a small sensor?"

Guess what this LX7 is likely to have a super quality lens, just like the LX5 does and the Samsung TL500 (EX1 in Europe) and now the new Samsung EX2.

You originally made a preposterous claim, and now you've made the exact point that affirms the preposterousness of the original claim.

Duh, lenses have different diffractions and imperfections. Or put differently: My LX5 pictures are clearer and sharper with better colour than what comes out of my Canon G6--printed same DPI.

I do know that a super quality lens on the LX7 sensor will equal or better a very low quality lens on aps-c but it will also be significantly larger and more expensive to do so which is why i cant really see the point in that. If you are going to invest in a high quality lens then why would you waste it by sabotaging it's resolution by making it for a small sensor?

So you do not see the logic in this at all?
You consider it logical to use a large expensive lens design on a tiny sensor to possibly match the quality of a much more compact really cheap lens design on aps-c?

You do not see that even if this is possible that a quality lens on aps-c would be far superior? Which is the point i was making after all...

Did you even bother to compare the large format lenses to the leica's?

I think you simply still dont understand how optical quality scales with sensor size.

"You originally made a preposterous claim, and now you've made the exact point that affirms the preposterousness of the original claim."

You keep replying as if i was referring specifically to the quality of this particular lens as being horrible as compared to other F1.4 lenses perhaps when i made it quite clear many times already that i intended that F1.4 lenses in general are horrible or inferior to higher F-number designs.

You just keep completely missing the point and keep replying based on your own wrong interpretation of what i said.

"The problem with your entire argument is summed up nicely by something you posted a few hours ago as yet another reaction to my point"

I would really like to know what your point is exactly, you dont seem to have made any.

Mal82:

And a second preposterous claim by you: That F1.4 lenses are horrible.

Just try to familiarize yourself with actual lenses instead of paper claims and data sheets before making less than informed claims.

What exactly is your point? Do you just want to argue? I actually have something meaningful to say... Apparently you didnt notice, you were too busy protecting your ego.

Both the canon 50mm F/1.4 review i linked to and the leica F/1.4 data sheets show that these lenses have over twice the resolution stopped down to f/5.6-8 than at F/1.4. And i should add: before you go claim that they have this high resolution stopped down is because of their ultra high quality, let me remind you that the F/2.5 lenses have the same resolution stopped down to F/5.6-8 so there is absolutely nothing superior about the quality of the F/1.4 lenses.

How can you still seriously claim that F/1.4 is not a horrible compromise for resolution?

"And a second preposterous claim by you: That F1.4 lenses are horrible."

What exactly was my first preposterous claim again? The one that you imagined i made?

Regarding size, for me the borderline is the Canon S100. Thicker than that and, to my taste, it doesn't matter anymore in terms of pocketability. And yes, while the Panasonic may be 1cm thicker from display back to lens front, it as at least some sort of grip to hold on to while the Sony needs one retrofitted.

Dimensions even level out more as soon as you add the mandatory viewfinders to both the Panasonic and the Sony ... uups, can't do that with the Sony ... so how am I actually supposed to shoot with it?

Oh, look the Panasonic takes an EVF or a hotshoe flash--two possibilities missing from the Sony RX100.

Sure at ISOs below 1000, and in well illuminated situations, the Sony is likely to best the Panasonic LX7 and the Samsung EX2--however pocket cameras are sometimes used in say social situations in dark restaurants. Looks like both the Samsung and the Panasonic may do better than the more expensive Sony in those situations. Too bad Sony crammed so many pixels into its sensor and too bad Sony didn't include the possibility of an EVF.

Professor999--

Let's see: A hotshoe and the electronics to support it don't add much weight.

Then one big reason people use EVFs is shooting outdoors in bright light. So Sony failed to account for daylight shooting. Kinda of dumb for a camera limited to ISO 1600.

Note well: Built in flashes rarely do bonce and aren't real powerful beyond about 5 feet anyhow.

So in a dark restaurant with someone signing on stage high ISO capacity is much more important than Sony's stupid 20MP count. Or if you can use flash, then a built in one simply will not do. And then things sure look better with the flash bounced off the ceiling.

Pro999--

Nope I'm allowed to change the conditions in the hypothetical restaurant.

Still not getting this point are you? The hotshoe itself doesn't weigh much and it was a mistake for Sony to leave it off. I wasn't commenting on the weight of an external flash, just the lack of that possibility for the Sony RX100.

Nope, EVFs make shooting in bright daylight much easier, articulated view screens can also help. The RX100 has neither.

Now about an LX7 disappointment: From the raws I've seen, and extracted, the LX7 isn't really usable at ISO 1600. Too bad with the latest firmware, the LX5 is perfectly useable up through ISO 1000.

Perhaps there'll be a fix.

$149 for an EVF isn't that much, though on the LX5 Panasonic's EVF lags too much--could have been fixed. Remember how much the EVF for the Sony Nex 5n costs when making claims about expensive EVFs.

Because few small DSLRs can do the job--it's even a stretch for a D7000.

Professor999:

If I were referring to the weight of the external flash or the external EVF, then I would have referred to that weight and those items, not simply the hotshoe and supporting electronics.

That there are internal electronics supporting the hotshoe is not news to anyone, except it seems you.

So no you've made up a "moved goalpost" claim to buttress your still invalid claim. And the propensity to make things up doesn't do much for your case.

Your last odd paragraph:

There are APSC sensored cameras that use external EVFs, for example the Samsung NX100 and the Sony Nex 5n. Those are not DSLRs.

Remaining problems with the Sony RX100:

The problem is that this compact from Sony could have been a much better camera with the possibility of an
EVF and fewer MPs would have made it much more usable in lowlight conditions--as the Nikon 1s are.

EVFs in bright light:

Never said it was absolutely necessary to use an EVF in bright light,, just easier.

Pro999:

You most certainly did not spell out internal electronics. One of the reasons Sony most assuredly did away with the hot shoe was to save weight and some of that savings would come from internal electronics.

Clearly you don't know how engineers shave weight from weight sensitive items--like small cameras, automobiles, highend bicycles, Boeing 747s, etc.

Please stop prevaricating to make your claims seem valid. You've done that twice now.

No, your last paragraph introduced what you claim is necessary, for what I'm was never sure; you started on about dslrs. So I had to think you were thinking lowlight, so then of course I'm going to point out that there are APSC mirrorless cameras that accept external EVFs. (I guess you could be espousing using a dslr in bright sunlight too.)

You seem confused about cameras and engineering, instead of attacking me, try studying up on the subject.

No this discussing is not only about compacts.

You still appear confused.

That's "whom", and it's you.

You are probably the exception, especially on the video front.

We aren't discussing APSC sensors.

Guys, which will allow me to have more defocused backgrounds -bokeh- in your opinion?
RX100 or LX7?
That is what I want it for.
My Olympus XZ-1, with f1.8 and an 1/1.63" sensor, isn't giving me any, unless I do macro, and then, only a bit. (am I answering my own question here?)

I was particularly impressed with the "many who regularly use cameras" line, HowaboutRAW. How often do you use a camera? Twice a day? Five hundred frames a day? Do you know how often I use a camera? The internet makes those sort of throw-away insults possible.

Tom Goodman--

I shoot maybe 50 to 100 raws a week, sometimes many more.

That's regularly enough for me to make claims about shooting.

It would be simpler if you admitted your mistakes about F stops and reasons for wide apertures being used and moved on. You made a claim that really only applies to your very blinkered world view about still cameras and extrapolated that to mean everyone one who uses a camera with any frequency.

Even if you shot something like 500 raws a day, I wouldn't take your claims about lenses too seriously because of the mistake you made.

Most of my shots are at max. aperture, starting from F1.8.
Why? Because I keep ISO at 100.

Anyone shooting at maximum aperture most of the time is using the weaker capabilities of most lenses. Keeping ISO at 100 offers no significant advantage over bumping it up to 200 0r 250 and forces you to use apertures that are not optimal. HowaboutRAW, having set himself as the expert in these matters, can now have the floor.

Tom Goodman:

Right it's not news that lenses are sharper stopped down, but there are big reasons, both aesthetic and technical, for using wide open lenses. Yep I've used an F1.0 lens in the film past.

You simply can't claim that people don't/shouldn't use F1.4 lenses wide open, or you can make that claim, but then no one should treat your photo gear pronouncements with any seriousness.

GeorgeZ:

Does the Sony RX100 have a hotshoe that can take an EVF?

Though I do wonder if Panasonic has fixed the silly lens cap of the LX5?

LX7 has more interesting features and is likely to provide cleaner images, in spite of its smaller sensor, since the RX100 has (too) many MP and a slower lens.

Howabout RAW-
The Sony RX100 doesn't have a hotshoe for an EVF.
The LX7 does have a hotshoe but no EVF unless you want to shell out between 140-200 pounds for it.
Don't forget an external flash which can bounce and you're looking at around 800-900 pounds!

But probably you cannot use the RX100 one-handedly without sticking a grip on it...
And the LX7 has a brighter lens. So ISO 800 on LX7 would have to compete with ISO 1600 on RX100 regarding low light usage :-)

Professor999:

You're flash pricing is way incorrect.

correction:
i ownd the panasonic lx5 and the panasonic zx1

@tkbslc

Just for the record, the LX7 is the only camera in your list with a 24mm-XX lens.

The LX5 is 24-90, too, which is what that sentence was comparing to.

hotshoe is a feature that is way out of the league of a small-sensor camera - it's just not pertinent.
all the arguments about what you will need this for, are negated by the presence of a tiny sensor.
if you are willing to accept a small sensor in the second half of 2012, then you really aren't searching for a better product in the first place.

@tkbslc
how u dare to test my credibility, lets put your credibility and mine right on this site by webcaming mine and ur living! u joined since 2008 that dont means ur words weight more than mine, the fact i respond to this article, is because i am frustated about how little they innovate, what i mean to say we are living in crucial times where the smartphone are eating compact camera sales and look what the camera manufractures are doing just a little and asking a lot of money for minor upgrades, they can do alot more if they listing and research what people realy want and need, just take a look at the apps on ios and android market, they are innovating alot they are bringing change! yet the panason/samsun dont seems encourage that, wtf is samsung doing releasing 2 versions of camera one with wifi and the other doesnt support that, why not integrate wifi on all camera's and why not let people program more modes and apps for the cameras. lets take the challenge u and me go on webcam!