ThomasJohansson
New member
Hi, When you are out of range do you change to Dx-mode on the camera or do you crop your image in postprocessing? Or does it not matter on the image quality? Have a nice day!
Dx mode or crop?
- Thread starter ThomasJohansson
- Start date
If you would like to post, you'll need to register. Note that if you have a BCG store account, you'll need a new, separate account here (we keep the two sites separate for security purposes).
nmerc_photos
Well-known member
Cropping in post has the exact same result as DX mode in terms of IQ and pixels.
The only value in using DX mode is following:
Storage is so cheap these days, I do not mind having bigger files with more options for how to crop in post.
The only value in using DX mode is following:
- since the file size is smaller, it gives you more time before you hit an FPS buffer
- if you are having difficulty obtaining AF on a subject, DX mode reduces the area the camera must scan, so it can increase AF accuracy/speed
- if you know you will crop in post, it can save you time and file size
Storage is so cheap these days, I do not mind having bigger files with more options for how to crop in post.
No difference in IQ.
No.2 above is camera dependent. Improved AF in DX mode is unique to Nikon Z8/9. Makes no difference on Sony cameras(up through A1 at least). Not sure about Canon.
Arguably, FX has about a stop of dynamic range advantage over DX simply because of the working size of the sensor.
Full Frame vs DX for Bird/Wildlife Photography
I shot a D7100, D7200, D500 and now Canon R7. I don't recall anytime when someone said "wow, that photo would have been so much better if it was shot with a full frame sensor." The reason I'm posting this is we tend to agonize over the minutia of noise, grain, bokeh, corner sharpness etc...
bcgforums.com
That benefit applies to every pixel on the sensor. IOW the benefit doesn't go away if shooting a full frame sensor in crop mode or cropping in post.
Jonathan
Well-known member
I have a Canon R5, on my camera I see improvement in AF when switching to crop mode if it seems to be struggling to lock onto eyes when using the full image area.
As others have mentioned I don’t see a difference in image quality between crop mode in camera and cropping to the same size in post. I think @nmerc_photos nailed it in their reply.
I don't think that's true. Dynamic range among similar sensors (identical in this case) are not driven by pixel-level, but rather system noise, which is in turn inversly proportional to the surface area of the sensor. If you go to photonstophotos, look up dynamic range for same camera at FX and DX, you'll see about a stop drop.
StefanSC
Well-known member
Back when I was shooting an FX camera as my main camera, if I was out of range, I would:
1) Try to get closer to the subject.
2) Get a longer lens (if possible).
3) Crop (if I had enough pixels left).
4) Not shoot at all if the crop didn't leave me with a decent amount of pixels.
From an image quality point of view, using DX mode versus cropping the FX image to get the same framing after the fact gets you the same result.
In Canon It does improve af in ability to pick up eyes and hold on to them.
Last edited:
I think if one has a fast way to switch back and forth from full to crop and can do it without being flustered when action is happening then no problem. Personally it's another thing to think about so I rather think about it in post and concentrate on the shot. But if you know every shot will be for sure cropped then go for it, but remember to switch it back later so you are not surprised.
aringer
Active member
You can! I programmed my exp. compensation button to switch back and forth. The Z8 latest update made even easier, and the Z9 already had it.
aringer
Active member
I love the ability to switch from FX to DX, and from a practical point of view, for my images and the way I use them, I don't notice a difference in IQ, even if I crop my DX images.
There is for sure a noise and IQ difference cropping vs filling the frame, no difference using crop mode vs cropping in post as has been said. But if we could fill the frame we wouldn't be cropping I guess, except for artistic reasons. Maybe more flexibility to the final crop if more background to work with vs cutting it off with the crop mode.
One more difference is in DX mode all the AF boxes are larger in relative terms as a percent of the viewfinder or the frame. It can make it easier to use a Single, 1x1 Custom, or Small AF area (Dynamic or Wide).
I believe Steve and others tell us we can estimate the impact of noise by squaring the crop factor and multiplying by the iso. So a 1.5 crop would be similar to shooting at a little more than double the iso. Not that bad with ai noise reduction I guess, if the iso is reasonable to start with, but if iso is already high it can be out of bounds. Of course cropping in post also raises noise the same way.
What everyone said. I will add that an advantage of shooting full frame and then cropping is that if you are locating or tracking birds in a difficult situation (monotonous foliage, for example) the bigger FX frame makes it easier to find your bird. Kind of like having a "zoom."
ThomasJohansson
New member
Thanks alot for all posts! kind regards Thomas
I typically find myself shooting an 800mm pf at birds that are some distance from the camera. It is impossible to fully evaluate the potential of a crop just looking through a viewfinder. I just shoot at 800mm and take the leisure to pick through in post. In a recent shoot under these conditions I found a lot of surprisingly good post-crop keepers.
That is why I much prefer shooting a high megapixel camera with a high IQ prime lens.
That is why I much prefer shooting a high megapixel camera with a high IQ prime lens.
I am not the steadiest handheld shooter, and many subjects are moving fast. For me, I always shoot full fram and choose if/how to crop in post. That gives me the most options. If you consistently shoot at very high frame rates your choices may vary.
Chris K
Well-known member
DX or crop?
“Yes”.
I have my “Record” button on my Z9 set to toggle FX/DX. When I need more reach, I quickly reach for DX. And then later I crop if I need to.
I use DX mode because it makes exposure metering, checking focus, and aiming AF points boxes easier than when the subject is tiny in an FX viewfinder. I’m aware that there’s no real IQ difference… it’s all about ease-of-use.
“Yes”.
I have my “Record” button on my Z9 set to toggle FX/DX. When I need more reach, I quickly reach for DX. And then later I crop if I need to.
I use DX mode because it makes exposure metering, checking focus, and aiming AF points boxes easier than when the subject is tiny in an FX viewfinder. I’m aware that there’s no real IQ difference… it’s all about ease-of-use.
Chris K
Well-known member
That is a good point about the system noise. However, when using data from Photonstophotos there is another factor that comes into play. From my understanding of the explanation of his methodology the results are normalized for a standard output size. There is specific mention of correcting for circle of confusion when calculating results for testing full frame sensors in APS-C crop mode. So not sure how much of the difference in his "photo dynamic range" numbers are measured vs calculated.
Calson
Well-known member
It depends on the situation. When I was using DX mode with a D850 to photograph birds in flight I found it very difficult to get the framing I wanted and so switched to FX mode to have more of a margin for error. With a stationary subject it would be quite different.
I tried that approach, but I was surprised that my autofocus on FX mode was much better than I had expected. When I shot I was thinking I am not sure I got anything but then when I brought up the image in post I found the camera/lens did a lot better than I had thought. I was then free to work on the image.DX or crop?
“Yes”.
I have my “Record” button on my Z9 set to toggle FX/DX. When I need more reach, I quickly reach for DX. And then later I crop if I need to.
I use DX mode because it makes exposure metering, checking focus, and aiming AF points boxes easier than when the subject is tiny in an FX viewfinder. I’m aware that there’s no real IQ difference… it’s all about ease-of-use.
The image below is a deep crop of an 800mm shot of an owl in the field. At the time all I could see is there was an owl out there so I shot a 20 fps burst. Turns out I had good focus and with the below crop I was able to crop into a nice bird in its natural environment.
You can only see EXIF info for this image if you are logged in.