Shangri La
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On FF, is using DX mode same as shooting in FX then cropping? Will image quality (high ISO/DR/color depth) be compromised in any way since only partial of the sensor is used? Thanks.
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DX mode on FF?
- Thread starter Shangri La
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Yes, as long as you crop to exact DX size and then throw away the FX file.
No.
Shangri La
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If that's the case, the DX mode is pretty much just a useless gimmick then.
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Tharaphita
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It is same as you crop in post process. Part of sensor is used.
A for image quality. It is same but it is compromised also.
As reference for normal viewing.
Look it that way that either you look full(FX, not cropped) picture on screen and for DX mode result you zoom it in 50%, looking only partial picture and seeing much more noise and other unpleasing things on screen.
You can turn it off and just use DX lenses with your FX body. I still use the 35mm f1.8 and Tokina 12-24 without DX auto crop. The Tokina is fine from 18-24 and the 35 has dark corners but its not really a problem for my kind of shooting.
Is DX mode a useless gimmick? I don't think, sure there is a loss of resolution but the resulting image file is smaller as well. The big plus is that most users can go on using their DX lenses. With DX mode enabled they wont have to manually fix those photos taken from that old glass.
WIN WINWill DX Mode net you more detailed pictures of birds and bugs? No.
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Tony Beach
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Not at all. Works well with DX lenses, the files are smaller, and on my D800 with a battery grip and the right batteries I gain an extra fps. Personally, I have my D800 set to automatically use DX mode with DX lenses; for more fps with FX lenses I use 1.2x crop mode.
KSV
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Only valid reason to use DX mode on FX camera (even with DX lens!) is gain some FPS. Otherwise you always can crop and even get some fancy usage of DX lenses like square cropping. Another use to be reason is file size, but nowadays memory is cheap as dirt.
Nope. It's useful. For example, I have used my 10-20mm Sigma lens in DX mode on my D810. The resultant images were better than I could have gotten w/ my D300. When I can afford an ultra-wide FX lens, I'll not use that lens, but for the moment it's all I have...and I don't have to carry two bodies around!
Martin Grecner
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I do not think it is useless.
I can not imagine taking series of pictures in FX mode with DX lenses and then cropping all of them in post, that would simply take too much time.
Also, having the crop rectangle in the viewfinder helps you to compose correctly for DX. It happened to me once when I was shooting a DX lens in FX mode, and then found out that I can not crop the black corners out without loosing important parts of the image, as the subject was too big (exceeding the DX area).
Martin
moving_comfort
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This second answer was incorrect - the DR and noise of the cropped (and enlarged) image will be less than the native FF image was and in fact will be almost exactly the same as a native DX shot taken with the same-gen sensor.
Basically DX-mode is exactly mimicking a DX camera in output. You don't retain the FF SNR/noise advantage in DX mode.
Is DX mode useful? Sure, if you're shooting DX lenses you still own on your FF camera. It increases FPS, decreases memory card space requirements, and saves you some extra steps in post.
I think the 1.2x and 4:5 crop modes are useful as well.
What you are saying [I realize that you are not the only person who says this] is:
- Take two pictures w/ a DX lens [although I think the results would be the same if an FX lens was used]. Take one picture in FX mode and one in DX mode.
- Process the FX picture to crop it to DX dimensions.
- Compare the two images.
- Observe that the picture that was cropped in the camera has less DR and more noise.
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Shangri La
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If DX mode has compromised IQ then there must be something else going on other than simple cropping.
Because if you shoot in FX and then crop yourself, the cropped image, no matter how big/small, will have exactly the same IQ as the original FX file. Of course you get more sharpness towards the center of the image but that's due to lens and we're discussing sensor here.
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Shangri La
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I think this should be pretty easy to find out. Shoot in ISO12800 and compare the RAW files. If there exists any IQ difference, it should be pretty easy to spot.
Robin Casady
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jtan163
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Since it sounds like you're going to be taking this path I have a suggestion that might be sueful depending on which FX camera nd DX lenses you have.
If available try the 1.2 or 1.3 crop mode as well as pure DX (you might need to turn auto DX detection off and manually select the crop size).
Some DX lenses won't cover FX but will nearly cover 1.2 or 1.3 crop well enough that the vignetting is very minimal or acceptable depending on subject and you'll maintain a higher res.
E.g. with my Tokina 50-135 I get about 15MP on my D750 in 1.2 crop mode, as opposed to about 9MP with 1.5 DX mode.
Same with my 35mm 1.8GDX
Most of DX lenses can be used on FX with Kenko 1.4 teleconverter.
Here is a thread
I personally tested with 17-55 f2.8 => 24-78 f4 and 12-24 f4 =>17 - 34 f5.6, both work in full range.
Probably it will work with most DX lens (Nikon's teleconverters do not work with wide and standard zooms)
Since converter is still attached and covers the sensor when you changing lens, it's possible to change lens even at the places where usually photographers avoid doing this.
Here is a thread
I personally tested with 17-55 f2.8 => 24-78 f4 and 12-24 f4 =>17 - 34 f5.6, both work in full range.
Probably it will work with most DX lens (Nikon's teleconverters do not work with wide and standard zooms)
Since converter is still attached and covers the sensor when you changing lens, it's possible to change lens even at the places where usually photographers avoid doing this.
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