[SyncGuy]

Play with DOFMaster online. It is all about distances between camera, subject and background but equivalence is possible.

If one uses an "equivalent" focal length (e.g., 55mm on APS-C and 82.5mm on FF) then the field of view would be the same, so one wouldn't need to move closer. The depth of field would be shallower at the same aperture with full-frame, though.

Ah... I think i'm beginning to understand.. Thanks!

[Uluru]

Hmm.... Makes senses and that's why i state that the Pentax brand is mostly targeted to landscape photography, as was stated in the interview, due to the want of larger DoF.
And yes, separation is the quality of the background but when you're stuck within a 5m by 5m space and wanting to shoot full body length portrait, then what? ;P
PS: Once again, i am NOT bashing Pentax.. I still love using my Pentax but sometimes i would like more flexibility in DoF control.

Ah no. The aim was not to make DoF any larger than on an FF camera, but same for starts. However, it's the characteristics of the OoF of the image taken with an APS-C camera and its lens that it appears it is more suitable for landscape. That is a hidden assumption, which has taken its toll in people's minds so they by default think "the APS-C is for landscape". And they never learn anything more than that.

'Slower' maximum aperture on an APS-C Pentax lens evens out the inherent DoF disadvantage APS-C camera has, and makes focusing mechanism in the camera equally capable of acquiring a well focused photograph as the FF camera (which has more leeway and room for mistake due to its 50% larger DoF using same aperture).

That is the concept that, for some odd reason, baffles reviewers, especially PF here, as they compare keepers rate of the Pentax APS-C camera and Nikon FF camera, using the same aperture and draw wrong conclusions about the quality of each company's autofucus technology.

Most people confuse DoF (which is the distance around the subject in which one can get well focused details), with visual characteristics of the OoF (the gaussean blur visible before and after the DoF distance). The OoF characteristics has little to do with the DoF itself (using the same aperture on same fixed focal length lens, an FF camera has deeper DoF, not shallower, yet the OoF looks more blurred), but with the optical design of the lens for an imaging format and the transition between the DoF and OoF.

It's the special compressed quality of space of the transition area between the DoF and OoF that makes people wrongly conclude FF has a shallow DoF.

The larger the imaging format, and better the optical design, more control one has over the characteristics of the DoF to OoF transition and the quality of the OoF itself. That is why MF cameras are still in the game and no FF or an APS-C camera or lens can ever reproduce the visual quality of images taken with an MF camera and its good lens, the quality which usually blow people's mind. Especially in rendering the transition between the DoF area and OoF areas, we usually cannot even guess the distance of the subject from the camera and it has such a baffling and interesting visual quality that it looks magical.

[falconeye]

I stand by my premise that Nikon could have made the 80-400mm better than they did. As a minor example, The Sony 70-400mm is an overall sharper lens than (especially at 400mm) the Nikkor AF-S 80-400mm.

AFAIK, among the old Nikon 80-400, Canon 80-400, Sony 80-400 (both old and new) and new Nikon 80-400, the new Nikon comes out sharpest and the old one last. That's what I read, don't have any of the lenses. What's your source?

E.g., when refering to DxO lens tests of the 80-400 when paired with a D610 or A99 (same resolution), the Nikon wins for all scores. Although I admit that the sharpness field maps at 400/5.6 show an ever so slight advantage for the Sony.

Maybe, you got a bad copy or have AF tuning problems?

[jsherman999]

...
Most people confuse DoF (which is the distance around the subject in which one can get well focused details), with visual characteristics of the OoF (the gaussean blur visible before and after the DoF distance). The OoF characteristics has little to do with the DoF itself (using the same aperture on same fixed focal length lens, an FF camera has deeper DoF, not shallower, yet the OoF looks more blurred), but with the optical design of the lens for an imaging format and the transition between the DoF and OoF.

It's the special compressed quality of space of the transition area between the DoF and OoF that makes people wrongly conclude FF has a shallow DoF. .

I'm not sure if you're talking about some specific circumstance in which someone was confused by the quality of bokeh, or something, but unless I misunderstand you the above ^^ is wrong.

It has nothing to to with the quality of the OOF transition area, that's usually an attribute of the lens. FF has less DOF than aps-c in an image taken with the same FOV, distance to subject and aperture. (it really does, it's not an illusion or a misinterpretation.) To *get* the same FOV with FF, you'll need to use a 1.5x longer focal length on FF.

FF has more DOF when shooting with the same lens on both formats from the same position and aperture - but then the image will be radically different because it will have a different FOV.

.

[normhead]

I'm not sure if you're talking about some specific circumstance in which someone was confused by the quality of bokeh, or something, but unless I misunderstand you the above ^^ is wrong.

It has nothing to to with the quality of the OOF transition area, that's usually an attribute of the lens. FF has less DOF than aps-c in an image taken with the same FOV, distance to subject and aperture. (it really does, it's not an illusion or a misinterpretation.) To *get* the same FOV with FF, you'll need to use a 1.5x longer focal length on FF.

FF has more DOF when shooting with the same lens on both formats from the same position and aperture - but then the image will be radically different because it will have a different FOV.
.

Given that every camera comes with an Aperture ring, I'm not sure what value devising a comparison that involves a fixed aperture ring has. It really has no value unless discussing the throw away cameras that have one shutter speed and one Aperture setting. With such a camera the above statement would be completely true. But most of us don't use a camera like that. Most of us use cameras with adjustable Apertures, and those make such statements pretty much useless, because in real life, you change your aperture to achieve the depth of field you want on both systems.

You only care about what you can do at the same aperture, if someone welded both Aperture rings. Then you might select to use one format or the other based on DoF calculations and FoV. However, we don't use the same lenses or the same Aperture for the same scene in the real world. So the "fact" becomes an example of micro analysis, whereas a systems analysis approach is needed to understand the interactions of shutter Aperture, DOF and FoV.

If you look at the combination of possible shutter speeds and apertures for both cameras, probably up to 6 combinations for any scene.. and then pick the one where both cameras are at the same aperture and shutter speed, and make a statement based on that, you ignore at least 30 other comparisons, because you can compare every aperture on APS-c to every Aperture on FF. That would be 30 combinations without taking into account shooting one stop over and one stop under with one system or the other, and compensating for expire values in post processing, which will make the whole process exponentially more complex.

A disinterested observer, might ask, what would be the value of ignoring so much available data? Why just examine the one set of images where the apertures are the same and the distance is the same? While I guess from a technical perspective it's a nice point to understand, but only if you also understand the limitations, exceptions and how narrow an observation it is. Photographically it has very little value for systems as close together on the scale of sensor available as APS-c and FF. Two systems so close that people have to construct a theoretical micro analysis to emphasize a difference that is not often readily apparent.

[jsherman999]

Given that every camera comes with an Aperture ring, I'm not sure what value devising a comparison that involves a fixed aperture ring has.

Huh?

It really has no value unless discussing the throw away cameras that have one shutter speed and one Aperture setting.

Wrong. Equivalence is still true no matter what aperture, focal length, etc you choose to use in any format - laws of physics don't change, Norm! (but you know this, I think you're in an argumentive mood.)

With such a camera the above statement would be completely true. But most of us don't use a camera like that. Most of us use cameras with adjustable Apertures, and those make such statements pretty much useless,

Actually, the more you like to adjust your aperture the more you'll like FF.

because in real life, you change your aperture to achieve the depth of field you want on both systems.

Yes. Which is why it's nice to use a format that gives you more control over DOF, no?

Why just examine the one set of images where the apertures are the same and the distance is the same?

I'm not sure how to more clearly put this - you're not "examining one set of images", you're picking a point that has a common FOV and distance to subject so you can compare the output of the two formats given available lenses. This describes what photographers typically do, doesn't it Norm? 1) Pick your subject, 2) pick (or accept, if you can't move) your distance and corresponding focal length, 3) pick (or accept, if you're already wide-open) your aperture, 4) shoot?

With FF, you get a greater range of DOF (and noise) control in your #3 choice. Simple as that.

.

[Rondec]

I hate these full frame versus APS-C discussions. They all degenerate into the same trite arguments. The only thing I would say is that for most photographers, the little bit narrower depth of field with full frame is not going to make a big difference in most situations and in many, will be detrimental to the final photo. For most focal lengths of 30mm and over (on APS-C), there are lenses that are quite sharp with quite wide apertures that allow for narrow depth of field. Not as narrow as with full frame, but narrow enough for most people.

To me, this is the weakest argument for full frame, as I have seen way more photos spoiled by too narrow depth of field and a little front focus/back focus, than photos spoiled by a little too much depth of field. I am usually shooting at f2 to f4 on APS-C, not because I can't shoot wider, but because any wider and the end result will suffer.

[jsherman999]

Really typical Jay.. like "huh". what is that, "ya your right, but rather than give you credit, I'll grunt"...have a nice day...

I honestly do no know where you're coming from in that 'aperture ring' point. Please clarify.

By the way, I know you think you answered my post, but it was just your usual baloney. Dodge the question, mis-represent, be overly condescending. Bottom line, you said nothing, you were abusive, and that's 90% of your arguments.

I did answer your post. I'm just running out of ways to answer these things, I truly am. I and others have explained this countless times, and just when I think you're getting it, you regress, make odd comments like the one this morning and I just am at a loss where to take it. I've literally rehashed this again and again, and I shouldn;t need to - equivalence is a physical concept that's not really open to interpretation, and the benefits of larger sensors are hardly questioned by anyone, any more, other than as a value question.

My points are clear an concise.

On the contrary they are in fact often among the most muddled I've seen on the subject. Someone mentioned to me that they think you're actually just trolling this subject now, I'd like to think otherwise, but it would explain a few things.


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[normhead]

Huh?



Wrong. Equivalence is still true no matter what aperture, focal length, etc you choose to use in any format - laws of physics don't change, Norm! (but you know this, I think you're in an argumentive mood.)




Actually, the more you like to adjust your aperture the more you'll like FF.



Yes. Which is why it's nice to use a format that gives you more control over DOF, no?



I'm not sure how to more clearly put this - you're not "examining one set of images", you're picking a point that has a common FOV and distance to subject so you can compare the output of the two formats given available lenses. This describes what photographers typically do, doesn't it Norm? 1) Pick your subject, 2) pick (or accept, if you can't move) your distance and corresponding focal length, 3) pick (or accept, if you're already wide-open) your aperture, 4) shoot?

With FF, you get a greater range of DOF (and noise) control in your #3 choice. Simple as that.

.

Really Jay, that was brutal, condescending, full of mis-representations, completely lacking in any kind of respect or civility.
I'd report you to the mods, but last time I involved them in one of my little squabbles, they hit me with a three point penalty.

[monochrome]

Yeesh!! A framing hammer isn't a ball peen hammer. Either will pound a 10d nail into a 2x4, but turn it around . . . . .

[normhead]

I honestly do no know where you're coming from in that 'aperture ring' point. Please clarify.

.

If you think you understand it get back to me, I'll tell you if you're right. I spent 25 years teaching school, 15 years teaching photography, right now, you're down in the office in the normhead world.

[jsherman999]

I hate these full frame versus APS-C discussions. They all degenerate into the same trite arguments.

Especially when people are capable of bringing an interpretive view of physics to the argument.

The only thing I would say is that for most photographers, the little bit narrower depth of field with full frame is not going to make a big difference in most situations and in many, will be detrimental to the final photo. For most focal lengths of 30mm and over (on APS-C), there are lenses that are quite sharp with quite wide apertures that allow for narrow depth of field. Not as narrow as with full frame, but narrow enough for most people.

Certainly this is true, but here's another way to look at it:

Say you were able to buy an aps-c lens that had a 'turbo mode' button on it, and what this button did when pushed gave your lens 1.3 stops less DOF for the same FOV, while still retaining the same sharpness and contrast on the plane of focus, and giving you a little over 1 stop less noise. Meaning, at f/4 it doesn't really move to f/2.5, it retains the F4 sharpness while giving you an f/2.5 DOF. Just for that one button push. Then, after you took that shot or series of shots, say you wanted the f4 DOF back again - you simply push the button again to turn off 'turbo mode', back to regular aps-c shooting, back to the DOF and noise you had before.

Wouldn't that be a neat feature you'd consider paying something for?

The 'turbo mode' button 'on' setting represents the regular FF shot. The turbo mode 'off' setting represents stopping the FF camera down 1.3 stops to match the aps-c DOF and noise. Both options are always available to you when you shoot FF, you just have to use a 1.5x longer focal length.

(Now, imagine that you're a member of an online forum where some people consistently argue that the 'turbo mode' button is useless and is only useful for getting 'razor thin DOF'. You try to explain how it can be useful and fun in a lot of other situations, you even show examples... to little avail. )

Now, I will say that the FOV/DOF argument isn't important to a lot of people, understandibly so, and if that were the only advantage FF gave it would be dubious. But it's a big leap from that to it being useless.

.

[Rondec]

Especially when people are capable of bringing an interpretive view of physics to the argument.



Certainly this is true, but here's another way to look at it:

Say you were able to buy an aps-c lens that had a 'turbo mode' button on it, and what this button did when pushed gave your lens 1.3 stops less DOF for the same FOV, while still retaining the same sharpness and contrast on the plane of focus, and giving you a little over 1 stop less noise. Meaning, at f/4 it doesn't really move to f/2.5, it retains the F4 sharpness while giving you an f/2.5 DOF. Just for that one button push. Then, after you took that shot or series of shots, say you wanted the f4 DOF back again - you simply push the button again to turn off 'turbo mode', back to regular aps-c shooting, back to the DOF and noise you had before.

Wouldn't that be a neat feature you'd consider paying something for?

The 'turbo mode' button 'on' setting represents the regular FF shot. The turbo mode 'off' setting represents stopping the FF camera down 1.3 stops to match the aps-c DOF and noise. Both options are always available to you when you shoot FF, you just have to use a 1.5x longer focal length.

(Now, imagine that you're a member of an online forum where some people consistently argue that the 'turbo mode' button is useless and is only useful for getting 'razor thin DOF'. You try to explain how it can be useful and fun in a lot of other situations, you even show examples... to little avail. )

Now, I will say that the FOV/DOF argument isn't important to a lot of people, understandibly so, and if that were the only advantage FF gave it would be dubious. But it's a big leap from that to it being useless.

.

As of right now, every camera out there is a compromise. The D800 has a slow frame rate and huge files. Its "turbo button" also costs more than a thousand dollars more than a K3. The D600 loses something with regard to frame rate, build, buffer, and maximum shutter speed -- and it still costs more than the K3. As of now, I have a nice stable of Pentax glass and am not particularly enamoured with the turbo button (I mostly shoot landscapes). If Pentax comes out with full frame, my wife will probably get one, because she shoots a lot of portraiture and some weddings and it will be more useful for her. But flogging the narrow depth of field horse just doesn't do much for me. Particularly not when you realize the cost it comes at.

[jsherman999]

As of right now, every camera out there is a compromise. The D800 has a slow frame rate and huge files. Its "turbo button" also costs more than a thousand dollars more than a K3.

Keep in mind that the 'turbo button' is only one feature, not the entirety of the difference. It just seems to be the one that gets misunderstood (and argued about) the most.

....But flogging the narrow depth of field horse just doesn't do much for me

Person A: This apple is blue!

Person B: Actually, it's red, see...

Person C: Quit flogging the apple issue, person B!!

Person B: OK.



.

[ElJamoquio]

person a: This apple is blue!
Person b: Actually, it's red, see...

Person a: This apple is blue!
Person c: Actually, it's red, see...

Person a: This apple is blue!
Person d: Actually, it's red, see...

Person a: This apple is blue!
Person b: Actually, it's red, see...

Person a: This apple is blue!
Person c: Actually, it's red, see...

Person a: This apple is blue!
Person d: Actually, it's red, see...

Person a: This apple is blue!
Person b: Actually, it's red, see...

Person a: This apple is blue!
Person c: Actually, it's red, see...

Person a: This apple is blue!
Person d: Actually, it's red, see...

.

ftfy...