I understand that diffraction is diffraction and that it's not worse on higher MP sensors it's just that it's effect is more pronounced or perceptible. And that makes sense. Would it's perceived effect be reduced if shooting in 26MP mode on the A7RV? I'm leaning towards 'no' just because the sensor is what it is (60MP) and whatever wizardry Sony is using to spit out a 26MP version would most likely be a down sized version
Diffraction is a function of pixel density....so....if you do APS-C, pixel density doesn't change. If you do just the smaller RAW file, then again....that was taken from the same density of pixels to start with, so diffraction already had its impact.
I assume you are talking about 26MP Med RAW or jpg and not aps-c mode. In that case the diffraction limit would change to what would be expected in a 26mp FF sensor. Now for the irony: The 60mp sensor shot past the diffraction limit will still provide more detail than the 26MP image shot below the diffraction limit (same aperture for both shots).
The diffraction limit is not a hard limit where everything goes to hell suddenly or all of a sudden there is a hard limit to resolution. I think it scares photographers more than it should and adjustments based on fear of diffraction do more harm than good for the quality of the photos.
I find f5.6 - f8 on 60mp is about the sweet spot for detail before diffraction kicks in. F/11 is certainly usable and tsdevine has shown many examples at f/16 that look real nice and benefit from the extra depth of field. From a technical standard you could focus stack f/5.6 to the depth of field from f/16 and get a better image, but that requires the subject remain stationary, on tripod , etc. I avoid shooting past f/16 as that will just be soft. But I try not to worry about diffraction and stop down as needed for depth of field. A better understanding of hyperfocal distance vs focal length would help in thinking about the proper aperture for a given situation.
As a physicist I am certainly guilty of having worried more about diffraction than was needed. I don't even give it a second thought up to f/11 now.
This is an interesting subject, and there is some reasonably good quality information that is available on the subject. Look at https://www.josephjamesphotography.com/equivalence/#diffraction
Here are some relevant quotes from this paper:
"Diffraction softening is the result of the wave nature of light representing point sources as disks (known as Airy Disks), and is most definitely not, as is misunderstood by many, an effect of light "bouncing off" the aperture blades. The diameter of the Airy Disk is a function of both the f-ratio and the wavelength of light: d ~ 2.44·λ·f, where d is the diameter of the Airy Disk, λ is the wavelength of the light, and f is the relative aperture. Larger relative aperture (deeper DOFs) result in larger disks, as do longer wavelengths of light (towards the red end of the visible spectrum) so not all colors will suffer from diffraction softening equally. The wavelengths of light in the visible spectrum differ by approximately a factor of two, so that means, for example, that red light will suffer around twice the amount of diffraction softening as blue light."
"A common myth is that smaller pixels suffer more from diffraction than larger pixels. On the contrary, for a given sensor size and lens, smaller pixels always result in more detail. That said, as we stop down and the DOF deepens, we reach a point where we begin to lose detail due to diffraction softening. As a consequence, photos made with more pixels will begin to lose their detail advantage earlier and quicker than images made with fewer pixels, but they will always retain more detail."
This agrees with what @tschopp already stated in the above post.
I also agree about the f/5.6 - f/8 being the upper "sweet spot for detail" - the diffraction becomes noticeable from f/8.
Note also that diffraction in systems with cropped sensors correlates with the crop factor. For example, when the crop factor is 2, then the diffraction can be expected from f/4 (rather than from f/8), with a micro-four-thirds system. Whether this diffraction should be visible is a different question. What is seen when pixel-peeping at 400% isn't going to be visible when looking at a full-sized image. Thus, while we need to be aware of diffraction, all practical decisions about the aperture should be mostly guided by considerations of the needed DOF or needed amount of light.
I found one of the comments from @ruthenium interesting about diffraction vs crop factor. Small sensors are often stated to have a depth of field advantage. It seems more accurate to say for a given angular view, focal distance, and depth of field the amount of detail available is limited by diffraction. The perceived depth of field benefit of crop sensors might be better stated as an unwillingness to stop down sufficiently on full frame. Of course there are computational ways around diffraction. You can apply focus stacking or deconvolution.
On the bright side for astronomy it is a sign of quality optics to say they are diffraction limited.
jakelindsay wrote:
I understand that diffraction is diffraction and that it's not worse on higher MP sensors it's just that it's effect is more pronounced or perceptible. And that makes sense. Would it's perceived effect be reduced if shooting in 26MP mode on the A7RV? I'm leaning towards 'no' just because the sensor is what it is (60MP) and whatever wizardry Sony is using to spit out a 26MP version would most likely be a down sized version
Use case is Macro.
I agree with you. That being said I am not sure what kind of algorithm A7rV uses when scaling down the raw to 26mp. Algorithm does not change the laws of physics but it plays an important role in perceived image quality. My own experience is that A7rv 26mp raw is not the same quality as genuine 26mp full frame sensor.
tuomkok wrote:
My own experience is that A7rv 26mp raw is not the same quality as genuine 26mp full frame sensor.
I find that remarkable. Up until now, I've only read the exact opposite on this topic. As an outsider, in situations where some observe one thing and others the opposite, I would assume that the difference is completely negligible in practice.
jakelindsay wrote:
I understand that diffraction is diffraction and that it's not worse on higher MP sensors it's just that it's effect is more pronounced or perceptible. And that makes sense. Would it's perceived effect be reduced if shooting in 26MP mode on the A7RV? I'm leaning towards 'no' just because the sensor is what it is (60MP) and whatever wizardry Sony is using to spit out a 26MP version would most likely be a down sized version
Use case is Macro.
The way you reason about this is a bit odd to me.
Assume an ideal lens with a perfectly circular aperture. At its widest setting (e.g., f/1.4), it achieves maximum resolution. As the lens is stopped down, the resolving power gradually decreases due to diffraction.
The so-called “diffraction limit” is reached at the aperture where the resolution of this ideal lens falls below the resolving capability of the sensor.
It follows that a non-ideal lens will also be below the sensor’s resolving capability at this aperture, but it may have already fallen below that threshold at wider apertures, or even at all apertures if the lens is simply not very good.
When you shoot the A7RV in 26MP mode, it can resolve no higher than 26MP. For that reason you would need to stop down the lens a bit more before hitting the so-called "diffraction limit"
It is my opinion that very few lenses can out-resolve the A7RV at any aperture. For your Macro use case, I would suggest shooting at the aperture where the lens is at its sharpest, and then use focus stacking to get sufficient depth of field.
Using pixel shift will also extract more resolution. 4-way pixel shift already increases the effective sensor size through emulating a per-pixel RGB sensor as opposed to a bayer layout sensor. This doubles the resolution of the green channel and quadruples the resolution of the red and blue channels. 16-way pixel shift goes further by emulating an even higher resolution RGB sensor
tschopp wrote:
I found one of the comments from @ruthenium@ interesting about diffraction vs crop factor. Small sensors are often stated to have a depth of field advantage. It seems more accurate to say for a given angular view, focal distance, and depth of field the amount of detail available is limited by diffraction. The perceived depth of field benefit of crop sensors might be better stated as an unwillingness to stop down sufficiently on full frame. Of course there are computational ways around diffraction. You can apply focus stacking or deconvolution.
On the bright side for astronomy it is a sign of quality optics to say they are diffraction limited....Show more →
First, that comment on diffraction vs. crop factor was made assuming that a FF and a cropped-sensor system are set to take equivalent images. For example, a FF system has a 24mm lens closed to f/8, and a micro-four-thirds system has a 12mm lens closed to f/4. Both system have the lens iris closed to 3mm, hence the effect of diffraction is expected to be equivalent.
Those who say that "Small sensors ... have a depth of field advantage" are not familiar with the concepts of photographic equivalence. Related to this is the myth that when f-numbers are the same on a FF and a cropped-sensor system, then these can be used to obtain equivalent images. Another great myth is that a MF camera produces less noise in high-ISO images, in comparison to high-ISO images from a FF camera (because the larger MF sensor "captures more light").
I am system-agnostic and I like all three systems that I own and use: the micro-four-thirds OM-1 II, the full-frame A1, and the large-format GFX100S II. All three are a joy to use, although in different ways.
Diffraction is an optical phenomenon that affects all lenses equally at a given aperture.
The so-called “diffraction-limited aperture” varies depending on pixel density. But that’s not a difference in the amount of diffraction — it is a difference in what the camera/lens can record.
A camera and lens with 26MP full frame sensor and the same lens on a camera with a 60MP full frame sensor generate exactly the same amount of diffraction. (Folks who don’t think so need to review how digital sampling works.)
The diffraction-limited aperture on the 26MP example is smaller than on the 60MP sensor. I don’t have the exact numbers at hand (but someone is free to figure them out for me), however using fake apertures for teh purpose of the explanation, the optimal diffraction-limited aperture on the 26MP system might be f/8 while it might be f/4 on the 60M system. (Again, I’m pretty sure those numbers are not accurate — but the concept is.)
Does that men that there is more diffraction on the 60MP system? No, not at all. If you made photographs with that lens on the two camera at the 26MP system’s diffraction-limited aperture they would show the same amount of diffraction. If you repeated this at the diffraction-limited aperture of the 60MP system, the 60MP image would continue to get sharper, while the 26MP example would not. (It isn’t quite that simple, but that’s the general idea.)
tsdevine wrote:
Diffraction is a function of pixel density....so....if you do APS-C, pixel density doesn't change. If you do just the smaller RAW file, then again....that was taken from the same density of pixels to start with, so diffraction already had its impact.
gdanmitchell wrote:
Diffraction is not a function of pixel density.
Diffraction is an optical phenomenon that affects all lenses equally at a given aperture.
The so-called “diffraction-limited aperture” varies depending on pixel density. But that’s not a difference in the amount of diffraction — it is a difference in what the camera/lens can record.
A camera and lens with 26MP full frame sensor and the same lens on a camera with a 60MP full frame sensor generate exactly the same amount of diffraction. (Folks who don’t think so need to review how digital sampling works.)
The diffraction-limited aperture on the 26MP example is smaller than on the 60MP sensor. I don’t have the exact numbers at hand (but someone is free to figure them out for me), however using fake apertures for teh purpose of the explanation, the optimal diffraction-limited aperture on the 26MP system might be f/8 while it might be f/4 on the 60M system. (Again, I’m pretty sure those numbers are not accurate — but the concept is.)
Does that men that there is more diffraction on the 60MP system? No, not at all. If you made photographs with that lens on the two camera at the 26MP system’s diffraction-limited aperture they would show the same amount of diffraction. If you repeated this at the diffraction-limited aperture of the 60MP system, the 60MP image would continue to get sharper, while the 26MP example would not. (It isn’t quite that simple, but that’s the general idea.)
While this is good info, to me it's still semantics in the context of the OP, although I realize you were replying to someone else. In my post above, I was treating diffraction as a just a law of physics....an immutable fact (as you note, it's a function of aperture). So back to the OP's question... I don't think it matters whether he shoots it at native resolution, or APS-C mode, or a small or medium RAW. All of those options are derived from a sensor with a certain pixel density (it's a constant). (The OP was talking about using a single camera in different modes). So they will all be impacted by the inherent diffraction of the aperture any lens is shot at correct? Because the pixel density does not change in any of those scenarios, and if aperture is fixed then really it does nothing. Really the only thing you can control to minimize this...is shooting at wider apertures (and losing depth of field) or buying a camera with a lower pixel density that is less affected by what apertures you like to shoot at. But that is kind of cutting off your nose to spite your face, since you are choosing to lose resolving capability to avoid losing resolving capability. So that's why most people say just shoot your camera at the aperture you need to get the shot (even stopped down past where diffraction will be noticeable on the camera you are shooting). The only real way to "cheat" and have your cake and eat it too is to shoot at wider apertures and focus bracket/stack. But there an be challenges with doing that in all situations and it has its own quirks to deal with.
I guess there is an argument that if you shoot in APS-C on his camera, he'll need to back up in order to match the framing (although that changes perspective) and then he might be able to shoot at a wider aperture. But he's already down to 26 MP (from 60 MP) at that pont and now shooting from a further distance, which means small detail is even smaller. So that doesn't really seem like a win. So it still just makes sense to shoot it at native 60 MP and use more advanced sharpening techniques to try to minimize impact.
But I could very well be wrong on that. I don't have a degree in optics or physics, etc. I'm sure someone will point out where I went awry in the above.
tsdevine wrote:
While this is good info, to me it's still semantics in the context of the OP, although I realize you were replying to someone else. In my post above, I was treating diffraction as a just a law of physics....an immutable fact (as you note, it's a function of aperture). So back to the OP's question... I don't think it matters whether he shoots it at native resolution, or APS-C mode, or a small or medium RAW. All of those options are derived from a sensor with a certain pixel density (it's a constant). (The OP was talking about using a single camera in different modes). So they will all be impacted by the inherent diffraction of the aperture any lens is shot at correct? Because the pixel density does not change in any of those scenarios, and if aperture is fixed then really it does nothing. Really the only thing you can control to minimize this...is shooting at wider apertures (and losing depth of field) or buying a camera with a lower pixel density that is less affected by what apertures you like to shoot at. But that is kind of cutting off your nose to spite your face, since you are choosing to lose resolving capability to avoid losing resolving capability. So that's why most people say just shoot your camera at the aperture you need to get the shot (even stopped down past where diffraction will be noticeable on the camera you are shooting). The only real way to "cheat" and have your cake and eat it too is to shoot at wider apertures and focus bracket/stack. But there an be challenges with doing that in all situations and it has its own quirks to deal with.
I guess there is an argument that if you shoot in APS-C on his camera, he'll need to back up in order to match the framing (although that changes perspective) and then he might be able to shoot at a wider aperture. But he's already down to 26 MP (from 60 MP) at that pont and now shooting from a further distance, which means small detail is even smaller. So that doesn't really seem like a win. So it still just makes sense to shoot it at native 60 MP and use more advanced sharpening techniques to try to minimize impact.
But I could very well be wrong on that. I don't have a degree in optics or physics, etc. I'm sure someone will point out where I went awry in the above....Show more →
Indeed, the situation is a bit different when comparing different formats such as FF and APS-C.
I’d just add that it does matter if he shoots in APS-C mode, since the unchanging measurement of diffraction blur at a given aperture at the sensor accounts for a larger percentage of the frame width. The simple answer there is to make the same kinds of aperture decisions that you would make when using an APS-C camera — e.g. the effect of diffraction blur becomes significant sooner as you stop down on the smaller format. For example, to generalize, if you would be happy using f/16 on a full frame sensor camera, you’d be happy using f/11 on APS-C. If you feel that f/22 is pushing diffraction blur too far on FF, then you’d probably feel the same way about f/16 on APS-C. (Updated for clarity)
And I don’t have a degree in optics of physics either. Mine are in… music. (Well, OK, music theory and composition with an emphasis on electroacoustic music.)
gdanmitchell wrote:
Indeed, the situation is a bit different when comparing different formats such as FF and APS-C.
I’d just add that it does matter if he shoots in APS-C mode, since the unchanging among of diffraction blur at a given aperture accounts for a larger percentage of the frame width. The simple answer there is to make the same kinds of aperture decisions that you would make when using an APS-C camera — e.g. the effect of diffraction blur becomes significant sooner as you stop down on the smaller format. For example, to generalize, if you would be happy using f/16 on a full frame sensor camera, you’d be happy using f/11 on APS-C. If you feel that f/22 is pushing diffraction blur too far on FF, then you’d probably feel the same way about f/16 on APS-C.
And I don’t have a degree in optics of physics either. Mine are in… music. (Well, OK, music theory and composition with an emphasis on electroacoustic music.)...Show more →
Okay, I get (now) that it is effectively worse in APS-C mode on his camera, but that would be only when he backs up to compose the shot similarly. Since at that point even though pixel density and diffraction doesn't change, the detail being projected effectively shrinks in size relative to the airy disk.
But if you didn't move the camera from its position, when switching from FF to APS-C mode on a given camera, there really should be no difference. At that point, you are doing the same thing as shooting the shot in FF and then cropping to APS-C in post. So the part that remains is 100% the same as what it was before you did the crop. In other words cropping off the non-APS-C portion of the shot doesn't change the part that is left. Again, this is only if the person doesn't recompose the shot.
The reality is though, that someone switching to APS-C would move the camera, since the desired composition would force it. And by doing that, the ratio of airy disc size to the size of the detail shifts and in essence penalizes the detail captured even more.
I know the above is repetitive, but the coffee hasn't even hit my coffee mug yet...
tsdevine wrote:
Okay, I get (now) that it is effectively worse in APS-C mode on his camera, but that would be only when he backs up to compose the shot similarly. Since at that point even though pixel density and diffraction doesn't change, the detail being projected effectively shrinks in size relative to the airy disk.
But if you didn't move the camera from its position, when switching from FF to APS-C mode on a given camera, there really should be no difference. At that point, you are doing the same thing as shooting the shot in FF and then cropping to APS-C in post. So the part that remains is 100% the same as what it was before you did the crop. In other words cropping off the non-APS-C portion of the shot doesn't change the part that is left. Again, this is only if the person doesn't recompose the shot.
The reality is though, that someone switching to APS-C would move the camera, since the desired composition would force it. And by doing that, the ratio of airy disc size to the size of the detail shifts and in essence penalizes the detail captured even more.
I know the above is repetitive, but the coffee hasn't even hit my coffee mug yet......Show more →
Tim, this argument "cropping off the non-APS-C portion of the shot doesn't change the part that is left" is correct only if you, for example, print an image, then crop off the non-APS-C portion with scissors. Then, the cut out APS-C portion is indeed unchanged.
Things should change if you decided to enlarge the cut out APS-C portion up to the size of the original print. Then the Airy discs are going to be enlarged by the crop factor = 1.5. The same should happen when the APS-C crop is displayed at the same size as the uncropped image on a display.
This consideration - the same output size(!) - is the key and critical part of the equivalence arguments.
For example, an APS-C crop from a FF image taken with a 100mm lens set to f/2, and in-camera ISO 100 is equivalent to a FF image taken with a 150mm lens set to f/3, and in-camera ISO 225.
Note the f-number change from 2 to 3. This is what often leads to debates, as people argue that a crop from an image should have the same f-number as the full image. Once again, this is true only when the crop is not resized, as long as the crop is viewed at its original size.
(Added in edit) Related to the above is why an F4 lens becomes an F5.6 lens with a 1.4x TC and an F8 lens with a 2.0x TC. This is the inevitable result of cropping (cropping in-lens, in this case) then magnifying the crop to full frame. The Airy discs should be affected the same way, by the crop factor.
tsdevine wrote:
Okay, I get (now) that it is effectively worse in APS-C mode on his camera, but that would be only when he backs up to compose the shot similarly. Since at that point even though pixel density and diffraction doesn't change, the detail being projected effectively shrinks in size relative to the airy disk.
But if you didn't move the camera from its position, when switching from FF to APS-C mode on a given camera, there really should be no difference. At that point, you are doing the same thing as shooting the shot in FF and then cropping to APS-C in post. So the part that remains is 100% the same as what it was before you did the crop. In other words cropping off the non-APS-C portion of the shot doesn't change the part that is left. Again, this is only if the person doesn't recompose the shot.
The reality is though, that someone switching to APS-C would move the camera, since the desired composition would force it. And by doing that, the ratio of airy disc size to the size of the detail shifts and in essence penalizes the detail captured even more.
I know the above is repetitive, but the coffee hasn't even hit my coffee mug yet......Show more →
Moving the camera does not give you the same picture. The relationship between subject and background/foreground elements changes, just like it does if you use a different focal length lens.
In any case, whatever the other variables, if you make same-size prints/displays of the APS-C image and the FF image shot at the same aperture, the diffraction will be greater on the APS-C image. (That’s why we typically — to use the rough rule of thumb — shoot one aperture larger on APS-C when diffraction is a concern.)
Of course, if you crop a FF image to APS-C size then the rules that apply to APS-C sensor cameras apply.
Yes, in the thread before. I mentioned that moving the camera to re-frame changes perspective. That wasn’t the focus of my point in the last reply, but I did mention that in the prior one.
I’m a firm disbeliever in “zoom with your feet”. Minor adjustment…okay. But there is often a perspective you are going for that is a core component of composition.
gdanmitchell wrote:
Moving the camera does not give you the same picture. The relationship between subject and background/foreground elements changes, just like it does if you use a different focal length lens.
In any case, whatever the other variables, if you make same-size prints/displays of the APS-C image and the FF image shot at the same aperture, the diffraction will be greater on the APS-C image. (That’s why we typically — to use the rough rule of thumb — shoot one aperture larger on APS-C when diffraction is a concern.)
Of course, if you crop a FF image to APS-C size then the rules that apply to APS-C sensor cameras apply....Show more →
ruthenium wrote:
Tim, this argument "cropping off the non-APS-C portion of the shot doesn't change the part that is left" is correct only if you, for example, print an image, then crop off the non-APS-C portion with scissors. Then, the cut out APS-C portion is indeed unchanged.
Things should change if you decided to enlarge the cut out APS-C portion up to the size of the original print. Then the Airy discs are going to be enlarged by the crop factor = 1.5. The same should happen when the APS-C crop is displayed at the same size as the uncropped image on a display.
This consideration - the same output size(!) - is the key and critical part of the equivalence arguments.
For example, an APS-C crop from a FF image taken with a 100mm lens set to f/2, and in-camera ISO 100 is equivalent to a FF image taken with a 150mm lens set to f/3, and in-camera ISO 225.
Note the f-number change from 2 to 3. This is what often leads to debates, as people argue that a crop from an image should have the same f-number as the full image. Once again, this is true only when the crop is not resized, as long as the crop is viewed at its original size.
(Added in edit) Related to the above is why an F4 lens becomes an F5.6 lens with a 1.4x TC and an F8 lens with a 2.0x TC. This is the inevitable result of cropping (cropping in-lens, in this case) then magnifying the crop to full frame. The Airy discs should be affected the same way, by the crop factor....Show more →
What I am saying is that when you switch from FF mode to APS-C mode on a camera, and don't recompose, the same image is being projected on the same sensor. It's just that non-APS-C portion is effectively "turned off". I realize that if you recompose (aka back to to reframe, even though that changes perspective), then things will change. But just switching a camera in to APS-C mode is effectively cropping at capture time.
In reality that will force you to recompose. So it's probably just an academic observation.
tsdevine wrote:
What I am saying is that when you switch from FF mode to APS-C mode on a camera, and don't recompose, the same image is being projected on the same sensor. It's just that non-APS-C portion is effectively "turned off". I realize that if you recompose (aka back to to reframe, even though that changes perspective), then things will change. But just switching a camera in to APS-C mode is effectively cropping at capture time.
In reality that will force you to recompose. So it's probably just an academic observation.
It is not clear what are trying to say here, and why are you saying that. We discuss diffraction in this thread.
-- I never suggested recomposing; this is not an issue.
-- "switching a camera in to APS-C mode is effectively cropping at capture time" - I know this.
When the resulting cropped image is viewed at the same size as you normally view full-frame images, then the Airy discs become larger by the crop factor than those in the uncropped image - hence there is more diffraction.
Thus, it is incorrect to say that "if you didn't move the camera from its position, when switching from FF to APS-C mode on a given camera, there really should be no difference." Everything (the focal length, the f-number, the effective ISO, and the dynamic range) should change (relative to the uncropped image) when the resulting cropped image is viewed or printed of the same size as the uncropped image.
ruthenium wrote:
It is not clear what are trying to say here, and why are you saying that. We discuss diffraction in this thread.
-- I never suggested recomposing; this is not an issue.
-- "switching a camera in to APS-C mode is effectively cropping at capture time" - I know this.
When the resulting cropped image is viewed at the same size as you normally view full-frame images, then the Airy discs become larger by the crop factor than those in the uncropped image - hence there is more diffraction.
Thus, it is incorrect to say that "if you didn't move the camera from its position, when switching from FF to APS-C mode on a given camera, there really should be no difference." Everything (the focal length, the f-number, the effective ISO, and the dynamic range) should change (relative to the uncropped image) when the resulting cropped image is viewed or printed of the same size as the uncropped image.
Switching to APS-C crop mode (same lens, same position, same focal length, same f-stop) does not change the physics of diffraction. The Airy disc size and blur pattern on the sensor remain identical. Any visible difference only appears later — from extra enlargement to the same output size, or if you recompose by moving the camera to restore framing.
tsdevine wrote:
Switching to APS-C crop mode (same lens, same position, same focal length, same f-stop) does not change the physics of diffraction. The Airy disc size and blur pattern on the sensor remain identical. Any visible difference only appears later — from extra enlargement to the same output size, or if you recompose by moving the camera to restore framing.
So I'm not disagreeing with you.
I never suggested recomposing; thus, this is irrelevant.
Also "The Airy disc size and blur pattern on the sensor" are practically irrelevant.
This discussion of diffraction is about how this phenomenon affects photos viewed either as printed or as displayed on-screen. Then, it is incorrect that "when switching from FF to APS-C mode on a given camera, there really should be no difference"
