[jpfisher]

Shot this over the weekend with the FA 31mm mounted to the Leica M:



If you've got the cash, it's your full-frame digital Pentax for the moment.

[jsherman999]

I have followed the debate about DoF with interest (and not a little bewilderment at the technicalities of the erudite arguments). I think it would be revealing if we could have a poll on the lines of "why I bought a FF camera" or maybe "why I want/need a FF camera". When I bought my D800, DoF was not even near the top of my list of considerations.

DOF control was probably third or lower on my list as well when I bought my D700 in Jan '10. I had a K20D with some very sweet lenses (still do), and for my low-light indoor AF needs I had a D90 with a few lenses as well - D90's AF was so much better, but for everything that didn't depend on AF I liked the look of my Pentax glass.

I eventually wanted better tracking, even better AF, and I was going to upgrade D90 --> D300... But just decided to spend a little more and get a bigger upgrade, as long as I was taking out the wallet.

I was also influenced by a short conversation I had with a pro standing at the counter of National Camera Exchange. I noticed he had a D700 and asked what lenses he used on it, and he kinda sheepishly said that he probably used his 50 1.8 the most, and then some other kinda pedestrian lens that I don't remember, and he talked about why for a bit... anyway, it actually made me excited to hear that because it was sort of like a real-world affirmation about what I'd been reading about, about how FF can bring your glass new life. It's one thing to know the math involved, it's another to hear real-life practicalities from a real-life shooter.

So, I got the D700. I did notice the DOF/FOV factor, especially with my Tamron 28-75, 50 1.8 and 180 2.8. It still isn't/wasn't the most important reason I wanted FF, but it is a nice bonus. (In 2012 I bought the D800 in a fever of want vs need when I saw those specs and read early usage accounts. )

As I've said before, the DOF control thing is misunderstood, false claims get made about it, so it gets discussed/explained so much. This leads casual observers to conclude that it's just really super important, because it's talked about so much.

.

[Aristophanes]

The biggest reasons (in order IMO...but I am right) for FF vs. APS:

1) ISO advantage from more signal
2) Better DR related to signal
3) Easier with the wides in lens design especially
4) More legacy backwards compatibility
5) Shallower DOF control
6) Likely greater resolution

Cons:

1) Much more expensive camera body
2) Larger, heavier camera body
3) Less telecentricity for longer FL's
4) Much bigger, long glass
5) Web imaging lessens visible difference via-a-vis APS
6) Newer sensors really require new glass

[jsherman999]

The biggest reasons (in order IMO...but I am right) for FF vs. APS:

1) ISO advantage from more signal
2) Better DR related to signal
3) Easier with the wides in lens design especially
4) More legacy backwards compatibility
5) Shallower DOF control
6) Likely greater resolution

Cons:

1) Much more expensive camera body
2) Larger, heavier camera body
3) Less telecentricity for longer FL's
4) Much bigger, long glass
5) Web imaging lessens visible difference via-a-vis APS
6) Newer sensors really require new glass

Pretty good list, I suppose I could quibble with some points but overall fairly accurate IMO.

Except for perhaps the last one - 'require new glass.' D800 does not require new glass**. You can maximize the output by getting the best, newest, largest most expensive glass, but that's not required to get better results with regard to resolution than you ever got before.

(** Unless 'new' means anything post 1975.)

[Nesster]

Another advantage is the larger view finder, making it easier to see and focus manually. For me the idea of 'filmless 35mm' photography is alluring

[Aristophanes]

Another advantage is the larger view finder, making it easier to see and focus manually. For me the idea of 'filmless 35mm' photography is alluring

For a DSLR yes, but that difference does not exist if EVF's come to dominate. It's APS or FF agnostic.

That's why I left it off the list.

[Barry Pearson]

So confess, why do you want/need/have bought a "full-frame" camera? Is DoF your main motivation? Or is it detail, IQ or just that you have a heap of legacy lenses? I'd love to know.

One thing I want may actually be an illusion! Perhaps others can comment. (It isn't the only thing I want).

I would like an FF sensor with at least the same pixel density at the current APS-C sensor cameras. In other words, an APS-C crop of a photo taken with the camera has about 16 megapixels. So the centre of the image is just like one taken with my current camera.

What I want from this is extra field of view, especially for actions shots - birds in flight, airshows, motor sports, etc. I get a high rate of failures because I haven't got the subject fully within the frame. I simply didn't aim accurately! I may have a sharp photo of a bird but one wing-tip is missing.

(And sometimes the subject is unexpectedly larger in the frame than I was expecting, and my current lens can't get it all in. This too often happens when I am using my DA* 300mm f/4 lens).

[Barry Pearson]

Another advantage is the larger view finder, making it easier to see and focus manually. For me the idea of 'filmless 35mm' photography is alluring

I used Pentax film SLRs from about 1967 to 2004. (Then I switched to digital). I still have a number of (no longer used) screw-mount and K-mount film SLRs. I recently looked through their viewfinders to judge whether I still liked them.

My conclusion was that the older the camera, the less I liked its viewfinder. I now wear spectacles when using a camera, and I struggle to see the whole of the frame on the older cameras. But this isn't the same problem with later film SLRs. It appears (but is it true?) that the angle subtended at my eye by the later cameras is smaller, and this makes them more usable.

And I find the "grain" of the viewfinder of the older cameras a bit obtrusive. It probably makes them more useful for manual focusing, but also more distracting. Mostly I don't manually focus. I used to have two LXs (before they were stolen!) They had interchangeable viewfinders and screens. I didn't make much use of that, but I probably would now.

Question: how much is the effect of the "larger view finder" purely to do with the screen size, and how much to do with the eyepiece? Could a different eyepiece make the viewfinder of APS-C sensor cameras appear wider? (That would presumably also make them a bit darker). Could a different eyepiece on an FF camera make the viewfinder appear smaller for people like myself? Or have I got this totally wrong?

ps: I recently used my Pentax Z-1p to take lots of photos with my DA and DA* lenses to judge their image circle, hence usability on an FF camera. (I've posted the link to the results here). I feel that the Z-1p viewfinder is smaller than those for my older film SLRs, but it was also harder to use for manual focusing. Unless I am mistaken, just having an FF camera doesn't dictate all the aspects of viewfinder size or ease of manual focusing. The nature (not just size) of the screen matters, and I think the eyepiece does too.

[Cynog Ap Brychan]

I would like an FF sensor with at least the same pixel density at the current APS-C sensor cameras. In other words, an APS-C crop of a photo taken with the camera has about 16 megapixels.

The D800 has a pixel density very near to the K-5: it gives an APS-C crop of about 15 MP. Interesting points about the viewfinders. I use a D800 and a K-5 and I don't notice much difference in the clarity of the viewfinders in practice. The D800 does not seem anything like as big as the viewfinder on my MX, for instance. And, like you as a spectacle wearer, I struggle to see all the screen on my older film cameras now.

[RonHendriks1966]

I used Pentax film SLRs from about 1967 to 2004. (Then I switched to digital). I still have a number of (no longer used) screw-mount and K-mount film SLRs. I recently looked through their viewfinders to judge whether I still liked them.

My conclusion was that the older the camera, the less I liked its viewfinder. I now wear spectacles when using a camera, and I struggle to see the whole of the frame on the older cameras. But this isn't the same problem with later film SLRs. It appears (but is it true?) that the angle subtended at my eye by the later cameras is smaller, and this makes them more usable.

And I find the "grain" of the viewfinder of the older cameras a bit obtrusive. It probably makes them more useful for manual focusing, but also more distracting. Mostly I don't manually focus. I used to have two LXs (before they were stolen!) They had interchangeable viewfinders and screens. I didn't make much use of that, but I probably would now.

Question: how much is the effect of the "larger view finder" purely to do with the screen size, and how much to do with the eyepiece? Could a different eyepiece make the viewfinder of APS-C sensor cameras appear wider? (That would presumably also make them a bit darker). Could a different eyepiece on an FF camera make the viewfinder appear smaller for people like myself? Or have I got this totally wrong?

ps: I recently used my Pentax Z-1p to take lots of photos with my DA and DA* lenses to judge their image circle, hence usability on an FF camera. (I've posted the link to the results here). I feel that the Z-1p viewfinder is smaller than those for my older film SLRs, but it was also harder to use for manual focusing. Unless I am mistaken, just having an FF camera doesn't dictate all the aspects of viewfinder size or ease of manual focusing. The nature (not just size) of the screen matters, and I think the eyepiece does too.

Thanks, going to use this in another thread................do I see aps-H advantage!!!!!!!!!!!!!!!

[Barry Pearson]

Here is a quick response to both of the following:

The D800 has a pixel density very near to the K-5: it gives an APS-C crop of about 15 MP. Interesting points about the viewfinders. I use a D800 and a K-5 and I don't notice much difference in the clarity of the viewfinders in practice. The D800 does not seem anything like as big as the viewfinder on my MX, for instance. And, like you as a spectacle wearer, I struggle to see all the screen on my older film cameras now.

And:

Thanks, going to use this in another thread................do I see aps-H advantage!!!!!!!!!!!!!!!

I've just found this "Understanding SLR Viewfinders" article by Mike Johnston. It appears to pre-date 2003, and talks about film cameras. But most of it is relevant to dSLRs too.

It describes with clarity what I was blundering towards! Key topics include "Magnification", "Eyepoint", "Brightness", and "Focus "snap"" (and lots of others). These parameters can be varied by design, and none of them is individually dictated by whether the camera is APS-C or FF. But presumably, since twice as much light falls onto an FF screen than onto an APS-C screen, an FF camera designer will be able to vary the parameters with more ability still to achieve brightness.

I think I can see why my Pentax film SLRs vary from the oldest to the newest. As more electronic information is provided round the sides of the image in the viewfinder, perhaps the magnification has to be reduced to make the whole lot visible. And as automatic focus has taken over, the focus-snap has become less important, and more attention has been paid to other factors such as clarity and brightness. Perhaps (I'm guessing) Eyepoint is limited by the need to avoid light entering the viewfinder through the eyepiece for various reasons such as automatic exposure accuracy and contamination of the image on the sensor in low light.

There has been a gradual change in the inevitable balance of compromises. And any FF camera from Pentax will also have to compromise, (if only on price), so I suspect some people won't get the 35mm-era viewfinder they hope for! But I would have thought that Pentax could (but I suspect won't) surprise us with extra options (such as interchangeable viewfinders or eyepieces). (Remember the LX!)

[Cynog Ap Brychan]

There is an electronic device in my camera that changes the wonderful Bresson-esque images I see through my viewfinder into the dross that gets written to the card. I'm convinced of it!

[Nesster]

There has been a gradual change in the inevitable balance of compromises. And any FF camera from Pentax will also have to compromise,

Excellent analysis and info -- yes, things are a compromise. For my daughter's young eyes the APS-C size works great, for me it still does though the sheer real estate of a larger optical vf is starting to have its allure. The cost benefit -- 'performance' I might not want to pay for -- of the Nikon D600, for instance, is still a bit difficult to justify.

EVF's will get to the point where in most cases they are the equivalent of an optical vf, and yes, then it all becomes format agnostic.

The importance of the vf in a SLR is different than for other types of focus/composition aids. I'm happy going without, or with those old squinty aiming frames etc. Even with range finders --- sure it is nicer to have a larger one, showing what's outside the frame, plus a clear rf patch, but with non SLR's the photographer (or at least I) spend more of my attention on the outside of the camera/process, whereas with the SLR nearly all of my attention is crammed inside that eyehole

[beholder3]

[deleted]

[rawr]

The biggest reasons (in order IMO...but I am right) for FF vs. APS:

That's a decent list. I'm personally only really interested in advantages (1), (2) and (6).

A major deficiency of this sort of list is, of course, that the priorities are not related to the specific requirements of some shooting roles (sports vs landscape vs street vs weddings vs studio fashion vs macro vs photo journalism etc).