I like the idea of having a hig res camera and ability to crop the image using DX mode, which would give almost 24MP FX results, working like a zoom. Like using 50mm lens would give me around 20MP 75mm lens photos.
I understand that it is not exactly the same, but wanted to ask Z7/Z8/Z9 users - do you often use that crop mode, is it helpful?
Could I use 45MP camera and really use crop mode like I would have different lens, is it essentially good practice?
I have Zf at this moment and was wondering if buying used Z7II would be good idea for a travel lens.
Keep Zf as my MF and casual local use camera and Z7II as a travel camera where I dont have lots of lens with me and dont want to swap glass on site.
phinix wrote:
I like the idea of having a hig res camera and ability to crop the image using DX mode, which would give almost 24MP FX results, working like a zoom. Like using 50mm lens would give me around 20MP 75mm lens photos.
DX crop mode DOES NOT give almost 24MP FX results.
A Z7II DX mode file has a lower resolution (19.5 Mpix) and -most important- visibly more noise than, e.g., Z6/Z5II files.
Dynamic range too is worse.
If you can live with less Mpix, less DR and use AI noise reduction software at high ISOs (I recommend DxO Pure Raw 5 or 6), then the Z7II can be a good travel solution.
Cropping the central part of the sensor will work like a digital zoom. 19MP is still a lot of pixels and if you like the quality go for it. In a 1:1 comparison you will see the difference in reoslution and noise compared to the optical zoom.
The nice thinkg with mirrorless cameras is that you can assign a button to crop from, i.e. fx/dx and the viewfinder coverage is still 100%. AF object detection works a little better on enlarged objects, you need less memory, but you collect less quality - that said 19MP images were high resolution not long ago.
Technically, Ripolini above is correct - shifting to DX mode cuts your resolution to 19.5 max and reduces your DR. In practice the answer can be a bit more nuanced. Yes there is visibly (and measurably) more noise but how much that degrades your image depends on the light conditions, your shooting technique and how big you print your final image. And yeah if you pixel peep the difference can be visible - but that is looking at pixels, not images.
Many of us use DX as a lightweight travel alternative and if you go to the PtoP graph the difference between Z7II(DX) and the current DX sensor is negligible.
I'm saying the question is not which system (ZF or Z7II(DX)) will give you a 'better' image. I'm suggesting that depending on, again, technique, lighting conditions, final image size - and how you post-process - the difference in what the image ultimately looks like (and that's the point right?) isn't as dramatic as one might think.
On a high MP camera you might try taking the full frame shot and crop in post. That way you can also change the aspect ratio, etc. to best fit your desired image. I do this and it works well on my Z8. I use Lightroom for post processing with its AI-based noise reductio. It works very well.
There is only a single use case I’m comfortable turning DX on for my Z9 and that is birding when I am 100% sure I’d crop at least that much in post. It also helps the AF system to be in DX with smaller subjects.
Until Nikon introduces non-destructive DX or aspect ratios, I won’t use them for 99% of my shots because I want the freedom to crop in post instead.
It doesn't give almost 24MP FX results, it does give almost 21MP DX results. In short, it gives you a DX image almost indistinguishable from the IQ delivered by the current ~21MP DX lineup. That said, the IQ from current DX options is VERY good and as a practical matter I find few cases where I really see a practical difference between my modern DX results and my 24MP Z5ii (the difference is there when I pixel peep or push either DR or high ISO in the image, especially the ISO)
My primary use case for DX on the Z7 is to use DX lenses with IBIS, as an alternative to using them on my Zfc (which is my light carry/everyday camera). If not using a DX lens I would simply crop in post as Scott suggests, shooting DX with FX glass on a current 45MP FX body gives you nothing but less post-processing flexibility and somewhat more images per card.
But a 16-50/50-250 kit is a tiny carry kit, throw in the 24/1.7 or one or two of the small 3rd party f1.7/f1.8 primes and you have an inexpensive and excellent travel kit on either a Z7ii or a Z50ii.
I use it frequently as I find it helps visualize the shot I want. Sometimes I hit dx mode and the subject is still too small so I don't even bother shooting. in those cases it at least saves me wasted time in post. The alternative in many situations would be a second z8 and a 600 6.3. That is a bit much for my budget so I push the little red video button that I've programmed to dx mode and enjoy.
Ripolini wrote:
DX crop mode DOES NOT give almost 24MP FX results.
A Z7II DX mode file has a lower resolution (19.5 Mpix) and -most important- visibly more noise than, e.g., Z6/Z5II files.
Dynamic range too is worse.
If you can live with less Mpix, less DR and use AI noise reduction software at high ISOs (I recommend DxO Pure Raw 5 or 6), then the Z7II can be a good travel solution.
These DR charts are a bit misleading. Shooting in DX crop mode does not reduce DR any more than cropping the same image in post-processing does - the DR and noise do not change UNLESS you interpolate the cropped image back to full-frame size.
For web, social media, or even small to medium sized prints, you’d be hard pressed to notice a difference. If your photos just live on your hard drive and you just like knowing you have the highest quality pixels possible, then maybe don’t use DX mode.
Cliff L. wrote:
These DR charts are a bit misleading. Shooting in DX crop mode does not reduce DR any more than cropping the same image in post-processing does - the DR and noise do not change UNLESS you interpolate the cropped image back to full-frame size.
Or UNLESS you print the file to the same size (e.g., A2), right?
Ripolini wrote:
Or UNLESS you print the file to the same size (e.g., A2), right?
That's pretty much the same as what I said, for all intents and purposes... but realistically 99.999% of the images are dramatically downsized for posting to social media, so it's kind of a moot point.
Why are you downsizing due to the sociali medias?
I prefer to capture FX and then crop later if necessary.
If a cropped area is enlarged to the size before cropping of course the IQ (resolution, noise, DR) will be worse. But if cropped later you don't have use exactly that 3:2 DX size.
Ripolini wrote:
DX crop mode DOES NOT give almost 24MP FX results.
Why yes it does.
Because you cannot see the difference between a 20 Megapixel and a 24 Megapixel image, assuming the 20 Megapixel image was properly enlarged, beause the actual resolution difference is impossibly small to detect.
The smallest difference you could possibly, maybe see, is 16 Megapixel to 24 Megapixel, and even that is near impossible to see.
It just never ceases to amaze me how people dont understand that measurement choices have been picked by the companies for marketing purposes, not to best describe what you get. Megapixel is a stupid choice for a measurement. What interests is resolution, and for that you would want to for example pick the pixels of the longer axis.
Then a 6 Megapixel camera has 3000 pixels (2000 at the shorter axis) and a 24 Megapixel has 6000 pixels (4000 at the shorter axis) and one could immediately see that the 24 Megapixel camera had twice the resolution of the 6 Megapixel camera. You want twice the resolution of that, you would need 96 Megapixel.
But of course the camera companies want you to sell a sensor with one more Megapixel and act as if that actually mattered.
Nevermind actual Megapixel are sufficient for most purposes anyway, and have been for a very, very long time. A mere 6 Megapixel, if cleanly resolved, is enough for regular book size at 300 dpi. OK if you take into the consideration that the Bayer sensor matrix loses about 50% resolution, you will need 12 Megapixel.
Sauseschritt wrote:
...Nevermind actual Megapixel are sufficient for most purposes anyway, and have been for a very, very long time. A mere 6 Megapixel, if cleanly resolved, is enough for regular book size at 300 dpi. OK if you take into the consideration that the Bayer sensor matrix loses about 50% resolution, you will need 12 Megapixel.
However, I was referring to other aspects: noise and dynamic range, both related to pixel area or pixel pitch. If 6–8 megapixels are enough, and if sensor size doesn’t matter, then my compact camera Coolpix 8400 would – according to your reasoning – perform technically just as well as my Z6. Having owned both, I can assure you that’s not the case. Nor does the D7200 I used to own perform in the same way as the Z6 in terms of noise, dynamic range and/or blurring at the wider apertures.
Actually, depth of field (DoF) is different: by now, we should all have learned that, for the same framing, the smaller the sensor size, the greater the depth of field at the same aperture.
Finally, the diffraction-limited-aperture [DLA = pixel size/(1.22 x λ )] too is different; in the case of 24 Mpix sensors, assuming λ = 560 nm, i.e., the average wavelength of visible light, DLA is f/5.6 for APS-C (pixel size = 3,9 µm) and f/7 for FF (pixel size = 6 µm). This doesn't mean that we can't get sharp images @ f/8 with DX; in fact, DLA is the aperture at which diffraction does begin to affect image sharpness.
Therefore, a 20-24 MPix APS-C file is by no means the same as a 24 MPix full-frame file. If you consider the differences between the two files to be negligible, well, that’s another matter entirely, which has nothing to do with technical/photographic arguments.
phinix wrote:
So is there a difference between switching to DX mode on camera and taking a photo and taking a photo in full and cropping in post process?
Cropping during post-production offers greater flexibility, as several fellows have pointed out above.
But this procedure requires a certain ability to visualise how you will crop the image later. In the days of film, photographers using square medium format (6x6) often visualised the cropped image in advance, as it could be printed in a rectangular format (landscape or portrait; I’m thinking, for example, of a magazine cover page, where you might also have had to leave a little more space at the top for the magazine’s name...).
phinix wrote:
So is there a difference between switching to DX mode on camera and taking a photo and taking a photo in full and cropping in post process?
No.
But the process of turning DX crop on / off is more clunky on Z-Mount cameras than it is on eg Sony. And Nikon‘s crop is destructive i.e no way to get the full 45mp RAW file back as you would with almost any other brand (where the crop mode is just a preview and metadata to tell the software to crop).
I thought I’d use this feature quite a bit with my Z7 and I never actually do. So I’d say not worth it, even if it sounds nice in theory.
But the process of turning DX crop on / off is more clunky on Z-Mount cameras than it is on eg Sony. And Nikon‘s crop is destructive i.e no way to get the full 45mp RAW file back as you would with almost any other brand (where the crop mode is just a preview and metadata to tell the software to crop).
I thought I’d use this feature quite a bit with my Z7 and I never actually do. So I’d say not worth it, even if it sounds nice in theory.
I see, thanks for your input.
You see, I read about Leica having those 3 modes, 3 different resolutions, so you can switch and practically have one lens but ability to shoot like having 3 different focal lenghts. I thought its so cool, I thought I could have that with Nikonz at least two different focal lenghts, like 50mm and 75mm, or 20-30mm for example. Not having a huge zoom lens would be nice.
I may not understand how lens are made or designed, but always thought how the hell Leica can have such small lens in full frame, where other manufacturers make lens 5x bigger. Just take Leica lens and add AF motors, it shouldn't make them so big. But no, its apparently not that simple.
