All focus modes would improve if the subject is larger in the frame.
Shooting in Dx mode
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SCoombs
Well-known member
I actually observed this today. I was photographing a seagull flying around which was on the smallish size in the frame and the subject detection was only recognizing the whole bird's body and not the eye, so it was focusing on the body/wing area. I hit my button to swapped to DX mode and immediately the system started to focus on the eye and did so consistently in spite of the bird being no closer.
I'd say it does. As explained by apakett, the downsampling reduces several pixels into one. Depending on the method used to downsample it draws on data from neighboring pixels, so reduced noise and since dynamic range is based on the noise floor, also improved dynamic range.
Kuau
Member
So are you saying crop mode takes the full rez of the season then down sample it ? I thought it just cropped the image
apakett
Member
No, cropping throws away pixels. Downsizing where you have more pixels than the destination can use, downsamples the image.
I must be missing something or misunderstood the original post. Cropping and using the DX mode are not the same. (Yes sometimes they can be, but not always). DX mode collects only data from the DX area of the sensor. Cropping afterwards on the computer allows you crop different ratios and select which parts of the frame you like. I prefer not to use DX in the field if the bird is a reasonable size in the frame. I can always crop later.
If I encounter a rarely seen bird which is small in the frame and getting closer is not advised, I have no hesitation about flipping into DX mode. This is exactly what happened last week.
On a side note, I find the Z9 and the 180-600 5.6-6.3 produces very clean images in DX mode. This has surprised me more than once. For me the Z9 sensor and AF are a big factor. I don’t find I need extra noise reduction or sharpening. The lens may not be as sharp as my old 500F4G (which I still have) but it is producing better results and also allowing hand holding (it’s a much lighter lens).
In summary I have formed the view that I would rather flip into DX mode with the 180-600 than add in a 1.4TC. The results seem to be very good indeed. I think the extra stabilisation built into the Z lens is a big factor in making this a very usable lens. It is definitely much better value for money than I was expecting.
If I encounter a rarely seen bird which is small in the frame and getting closer is not advised, I have no hesitation about flipping into DX mode. This is exactly what happened last week.
On a side note, I find the Z9 and the 180-600 5.6-6.3 produces very clean images in DX mode. This has surprised me more than once. For me the Z9 sensor and AF are a big factor. I don’t find I need extra noise reduction or sharpening. The lens may not be as sharp as my old 500F4G (which I still have) but it is producing better results and also allowing hand holding (it’s a much lighter lens).
In summary I have formed the view that I would rather flip into DX mode with the 180-600 than add in a 1.4TC. The results seem to be very good indeed. I think the extra stabilisation built into the Z lens is a big factor in making this a very usable lens. It is definitely much better value for money than I was expecting.
No I'm not saying that. Crop mode is the same as cropping in post. Pixels thrown away. Here was apakett responding to scoombs, where the topic diverted a bit.
Shooting in Dx mode
I have been shooting more in Dx mode lately on my Z9 and 600 Pf. Positives for me : smaller file size , better AF. Negatives : smaller FOV I heard recently someone telling me that Dynamic range is smaller when shooting in DX mode: can anyone confirm this? When looking at Photons to Photos...
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Flyboy
Active member
Well...probably I'm a bit biased, but DX is what I have always shot, and my cameras both have the 1.3X on top of the DX crop factor. I don't use it a lot, but when I do, I take into account that it reduces the cameras' MP count to slightly more than my D 90 (12 MP) used to have. Could be I just didn't know or care about Dynamic Range but I never felt under gunned with that "small" MP count, and had no problem enlarging to my State photo competition's somewhat weird size requirements. If you have one of the Suuuuper Megapixel cameras, I wouldn't worry about a reduction in Dynamic Range, which may be all but unnoticeable.
apakett
Member
Dynamic range (noise) does not matter much as long as you have control over ISO. When you need to raise ISO due to either low light or a fast moving subject noise becomes an issue. It is less of a problem for Steve Perry and other professional photographers that shoot with a full frame camera and use long, fast lenses. They can also devote the time to wait for a subject to come to them.
The only question for me is can you see the difference in an A2 print or whatever the largest size your printer or print service does? My home printer prints to A2 size. I cannot really see any significant difference in the shots I take when I choose to use DX mode on the Z9. I rarely print at maximum size.
There are situations where the shot would benefit from cropping anyway. I can flip backwards and forwards between DX and FX. I am becoming equally happy to use either.
There are situations where the shot would benefit from cropping anyway. I can flip backwards and forwards between DX and FX. I am becoming equally happy to use either.
Like everything else in photography, the size of the viewed image, how far it is from the viewer, and the pixels dimensions all play a role. If I viewed an 8x10 paper print at arms length I would observe a certain impression of sharpness, noise, depth of field. If I cut out a 4x5 section of that same print and continued to view it at arms length it would have exactly the same sharpness, noise, and depth of field, since it is exactly the same print. However if I held it closer, enough to fill the same part of my vision that the 8x10 did, then I would in theory notice more noise, less DOF, and reduced sharpness. Same if I enlarged the 4x5 to 8x10 size, or reduced the 8x10 to 4x5 size.
What we call circle of confusion is not a fixed hard number, but varies with viewing distance and visual acuity of the viewer.
What we call circle of confusion is not a fixed hard number, but varies with viewing distance and visual acuity of the viewer.
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I understand what you are saying. It is correct but that’s not what i am saying. I am saying that taking a DX photo is already good enough. Thats it. I have been using my Z9 and long lenses for long enough to be very very clear about acceptable sharpness. The sharpness of the full frame Z9 image would probably reveal images at A1 size ( 23.39 x 33.11 inches) that look as good as a DX image at A2. I don‘t print that large. A2 is my maximum size. (16.53 x 23.39 inches.)
A DX image can be very sharp and very clear at the sizes I print at, you cannot tell which is which without looking up the metadata on the image. This means that looking at the image from the output I use is just fine. It is not necessary to shy away from using DX if that is the setting which has the subject in the size you want.
Using full frame may actually have better sharpness but you would need to print a huge image like an A1 to see the benefit of the full frame.
A DX image can be very sharp and very clear at the sizes I print at, you cannot tell which is which without looking up the metadata on the image. This means that looking at the image from the output I use is just fine. It is not necessary to shy away from using DX if that is the setting which has the subject in the size you want.
Using full frame may actually have better sharpness but you would need to print a huge image like an A1 to see the benefit of the full frame.
Sometimes we have to crop, we just don't have the reach. But if we did have the reach then for the same print size a downsized full frame with the subject filling the same part of the frame will be better. How much better to make it worth the bother is a matter of personal taste.