Dx mode or crop?

[DRwyoming]

Thanks for that, i'll give it a watch. What about if you achieve a lower iso in dx mode than fx?

Yup, if you can achieve about a stop and a third lower ISO in Dx mode than what you'd achieve at longer focal length to capture the same subject size in FX mode then they're about equal from a noise standpoint. If you can drive the ISO even lower with your zoom out and crop method then yes there would be some dynamic range and noise advantage.

For instance if you could capture the scene at ISO 6400 with the FX settings you'd want to shoot in DX mode at ISO 2500 for roughly equivalent noise and lower than that to see a noise improvement.

 

[Rectory Photography]

Yup, if you can achieve about a stop and a third lower ISO in Dx mode than what you'd achieve at longer focal length to capture the same subject size in FX mode then they're about equal from a noise standpoint. If you can drive the ISO even lower with your zoom out and crop method then yes there would be some dynamic range and noise advantage.

Got it....i'll have to experiment with that and see what the two files look like side by side..... I would need to put both files through my denoise processes to compare the finished images. I'm generally always trying for action images, so at the beginnings and end of the day i struggle with lenses such as the 180-600 at f6.3

 

[DRwyoming]

Got it....i'll have to experiment with that and see what the two files look like side by side..... I would need to put both files through my denoise processes to compare the finished images. I'm generally always trying for action images, so at the beginnings and end of the day i struggle with lenses such as the 180-600 at f6.3

Remember to compare them at the same output size. If you zoom both into say 100% zoom in a troll like LR you'll actually be looking at a different amount of the scene from the FX to the DX image. Zoom them both to show the same amount of the scene which is equivalent to displaying them both at the same output size.

 

[Rectory Photography]

Remember to compare them at the same output size. If you zoom both into say 100% zoom in a troll like LR you'll actually be looking at a different amount of the scene from the FX to the DX image. Zoom them both to show the same amount of the scene which is equivalent to displaying them both at the same output size.

Will do...thanks for the info.

 

[Anjin San]

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!

Post unless AF needs the help of a physically larger subject in the field of view…and since the pixels are the same size anyway I've never really understood why DX can help AF sometimes but it's an observed phenomena as we say…probably because the AF circuitry an iterate faster with fewer pixels to worry about although that still seems a bit of an iffy explanation to me…but nonetheless it's sometimes true so I just accepted it and moved on. And I stay in FX for BIF because it's easier to keep the darned bird in the viewfinder that way. Smaller file size and longer to hit the buffer are technically correct…but hard drive and card space is cheap and I rarely hit the buffer anyway in FX so longer isn't really 'better' for me.

 

[bleirer]

Thanks for that, i'll give it a watch. What about if you achieve a lower iso in dx mode than fx? Is it probable that in every case even when achieving a lower iso, i am not gaining any advantage in DX mode?

Folks here say to estimate the noise impact from cropping it would be the crop factor squared times the iso. So for example if you get down to 400 iso but crop to 1.5 crop factor it would be like iso 900. Plus you give up the resolution by having to enlarge the image vs using the focal length.

 

[arbitrage]

I have noticed times where there is no advantage as you say, but at others I just look at my iso and shutter speed and see an improvement. In those moments I can achieve my required shutter speed at my highest acceptable iso in dx mode zoomed out whereas in FX mode i can't.... i've no idea about the mathematics behind it.... I really just rely on comparing what i can achieve in the field.

You would just up your ISO in FX mode to get your SS you want. In the end you'll end up with the same IQ as you'll be throwing away more pixels using your zoom/DX method so that will be equivalent to just upping the ISO at the longer focal length (slower aperture) in FX mode.

 

[Calson]

The bottom line for me is that pre-crop using DX mode only works when the subject is motionless and taking up a small portion of the frame. If the subject is taking up less than 25% of the frame in FX mode then switching to DX mode may make sense.

Even with birds that were hovering in the air I found it easier to get the images I wanted with a FX DSLR (D5 and D850) than with my D500 DX camera. Having more flexibility to crop in post took priority over file size.

I can fix a lot of image issues in post but not a badly cropped image when taken or an out of focus image and so that is what I prioritize and do not worry about the rest. ISO was a big concern with the D2x that struggled above ISO 640 but today no full size camera cannot produce clean images at ISO 6400. I have had to unlearn my use of lower ISO settings which resulted in slower shutter speeds that were necessary with older cameras.

 

[RikWriter]

I use crop mode in the camera frequently because 1) I'm often photographing wildlife that I can't approach (such as wolves and bears) and need all the reach I can get, 2) 50 and 61mp files take up a buttload of card space and crowd the buffer more when I'm doing burst shots and 3) I find, contrary to what someone else has said about Sony, that shooting in crop mode does aid accurate AF.

 

[arbitrage]

I use crop mode in the camera frequently because 1) I'm often photographing wildlife that I can't approach (such as wolves and bears) and need all the reach I can get, 2) 50 and 61mp files take up a buttload of card space and crowd the buffer more when I'm doing burst shots and 3) I find, contrary to what someone else has said about Sony, that shooting in crop mode does aid accurate AF.

1) You don't gain any reach (as defined by more pixels per bear) by going into crop mode. Unless you just meant seeing the animal larger in the EVF.
2) Good reason for sure
3) I've seen time and time again where the Sony A1 won't activate Eye-AF icon in crop mode but just switching into full mode shows the Eye-AF square on the eye. I've had other times where I have eye-af going fine in FX but switch into DX and the eye-af icon disappears and it goes back to the dancing squares. What I don't know is if for AF in general (ignoring eye-AF icon) if shooting in DX improves AF hit rate or not. I've never been able to convince myself one way or the other.

I do shoot a lot in crop mode as I don't like wasting HD space and I like looking at the bird magnified in the EVF.

 

[RikWriter]

1) You don't gain any reach (as defined by more pixels per bear) by going into crop mode. Unless you just meant seeing the animal larger in the EVF.
2) Good reason for sure
3) I've seen time and time again where the Sony A1 won't activate Eye-AF icon in crop mode but just switching into full mode shows the Eye-AF square on the eye. I've had other times where I have eye-af going fine in FX but switch into DX and the eye-af icon disappears and it goes back to the dancing squares. What I don't know is if for AF in general (ignoring eye-AF icon) if shooting in DX improves AF hit rate or not. I've never been able to convince myself one way or the other.

I do shoot a lot in crop mode as I don't like wasting HD space and I like looking at the bird magnified in the EVF.

1. I don't gain any reach over cropping in post, but it does save me time since I KNOW I'm going to be cropping in post, so why wait?
3. I've never had the Eye-AF fail in crop mode, so I can't help you there. You should consult with Sony.

 

[NorthernFocus]

So which side is which? Posted at 100 percent resolution. Shot with same settings other than on was in DX mode. Focus point on nose in both shots. Identical processing, no luminance NR, no sharpening.

You can only see EXIF info for this image if you are logged in.

 

[ARClark]

So which side is which? Posted at 100 percent resolution. Shot with same settings other than on was in DX mode. Focus point on nose in both shots. Identical processing, no luminance NR, no sharpening.

View attachment 81696

The Spanish moss is definitely sharper on the left.

 

[Chris K]

DX mode on Nikon cameras also gives you smaller RAW files. The modest difference adds up when you're shooting 20fps!

 

[Ken Miracle]

I photograph birds on the move never knowing what is going to show up and when or where, deep in a bush, on a branch backlighted by bright sky, in flight etc..

I use Z9 with Z800 pf hand held target rifle style with a longer aftermarket lens foot resting in the palm of my hand.

I have my memory set button on Z800 set to toggle fx/dx. I have my control ring set to EV exposure compensation.

I toggle to dx whenever the image will need to be cropped significantly in post anyway or when I know/suspect it will help with AF.

Adjusting exposure control ring and fx/dx toggle all accomplished without taking my eye out of the viewfinder and in the heat of action while continuing to focus and even shoot if needed.

I am shooting for bird ID so everything else ie. noise etc. is secondary for me.

 

[MikeInMI]

The first reply from numeric_photos really nailed it. I'd add that I shoot Sony and have a button on my lenses that I program to put the camera in DX mode. I use it sometimes when something is smaller in the viewfinder as it helps me get a better look at my subject and what the final pic would look like. But then I usually go back to FF to actually capture the image -- probably to give me more flexibility when I crop.

​

 

[O]

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!

Full Frame or Cropped sensor mode which is better ........................on a Full Frame camera.

It depends much on what your exactly wanting to do, what lens, subject, and especially the conditions the main one being available light.

I prefer to CROP, as The actual distance between the subject and camera is exactly the same be it DX or FX, i think using matrix or single point dynamic range is telling.

Myself, i am a higher resolution full frame lover over DX any time, you can crop 45 or 61mp cameras so well, medium format cameras seem to have even better corp ability, and defiantly more ISO performance than any 35mm sensor.

Your best friend is Light and one of the best
informative tools is P mode (professional mode) LOL.

TEST

If you take your D850 say with a 50mm 1.8 D lens put the camera into P Mode, take a shot in full frame, floated ISO, choose a simple subject in say slightly lower light, say like a sofa cushion in the corner of your room with a hint of shadows.


Sample shot 1 on a D850

In Full Frame the camera will go to F1.8 and 640 ISO, note in single point metering range its 640 iso in Matrix its 500 go figure.

then change the setting in image area to DX mode with mask on, again in P Mode,

Sample shot 2 on a D850

In DX mode the camera will go F 1.8 and 1000 ISO in single point metering range, in matrix its 640 go figure.

Now my test may seem crazy or incorrect LOL ..............i mean there are theory's and points that can be argued enough to do your head in LOL, I have no qualified answers other than a quick simple hands on shooting in one mode or the other using P mode simply to determine a difference in light needs there for the least ISO needed, the brighter the light the narrower the differences which stands to reason, shooting FX or DX on a D850 or Z9 effects other settings you need to be prepared to consider.

On a FX camera the pixel pitch size is the same in DX or FX mode correct, now with a DX camera and FX camera the difference is pixel density as the DX pixel pitch size is much smaller effecting light intake and ISO performance.

A 24 mp DX camera may have 1600 iso capability where the full frame camera has say 3300 iso capability.

Bottom line what is your experience and preference is what matters.
If its that far that i need to use DX and then still crop, i pass on the shot in the first place, now that is me.

Again Light is always your greatest asset, measuring it in P node is handy-at times.

The next move to 60 mp with larger lens mounts is really going to give one some legs and meat for cropping, we have seen this in 12 mp to 45 mp.

Only an opinion

 

[cr_wildlife]

I agree completely with the comments at the start of this discussion by nmerc_photo. I almost never use DX mode on the Z9 and only do so when the subject is quite far away and the subject detection has trouble finding and locking on to the eye. Changing to DX definitely improves this, with increased and faster lock on the eye. I rarely hit the buffer on the Z9 at full frame, so that is not much of an issue for me. And while I sort of agree with Butlerkid (Karen), I see no reason to use a DX sensor in Nikon cameras, as it never gets as many pixels on the subject as full frame shot with the image filling the frame. Thus, the image can be printed at larger sizes, a great advantage if you print you images. One must remember, of course, that the human eye can't see the difference in sharpness from about 15 megapixels upwards, so this really only applies to print enlargements.

 

[Ken Miracle]

I agree completely with the comments at the start of this discussion by nmerc_photo. I almost never use DX mode on the Z9 and only do so when the subject is quite far away and the subject detection has trouble finding and locking on to the eye. Changing to DX definitely improves this, with increased and faster lock on the eye. I rarely hit the buffer on the Z9 at full frame, so that is not much of an issue for me. And while I sort of agree with Butlerkid (Karen), I see no reason to use a DX sensor in Nikon cameras, as it never gets as many pixels on the subject as full frame shot with the image filling the frame. Thus, the image can be printed at larger sizes, a great advantage if you print you images. One must remember, of course, that the human eye can't see the difference in sharpness from about 15 megapixels upwards, so this really only applies to print enlargements.

You triggered a walk down memory lane. At 75 I have changed my photographic emphasis and my Nikon Professional Services (NPS) is now "retired"

I still print large, less than I used to now, but I have no hesitation in using DX mode on my Z9 "if" that is what I need if the bird or other subject is to far to fill the frame to the level I want based on the composition I want.

As you noted the most common time I use DX is when the bird is distant, espeically if low contrast, to help AF and I would be cropping in post anyway.

I printed DX images from my D500 up to 8 feet but usually more often 11x14, 12x18, 16x20, 24x48. Majority was wildlife and mostly birds. D850 came along and I used D500 far less and went to DX as needed as I do now in Z9.

D6 was an entirely different FX tool low light and fast action it's forte I did not use DX mode that I remember.

Z9 dynamic range, new Z lenses, and other Z9 features let me do everything I used to with D500, D850 and D6 with one body that fits my new photographic interests well.

 

[O]

Arguably, FX has about a stop of dynamic range advantage over DX simply because of the working size of the sensor.

Agree,

Also i notice as i have explained lower down that different modes like DX or FX in the one camera reveals a slightly different ISO level, also matrix or single point metering range effects iso levels.

Only an opinion

 

[NorthernFocus]

... i think using matrix or single point dynamic range is telling.

... in single point dynamic range..
...in single point dynamic range...

Presumably "matrix" refers to matrix metering. But what is this "single point dynamic range"? I don't recall that D850 sold in North/South America has such mode/setting?

...now with a DX camera and FX camera the difference is pixel density as the DX pixel pitch size is much smaller effecting light intake and ISO performance...

Only an opinion

Really? With no further qualification? Are you referring to FX vs DX cameras with the MP?

Also i notice as i have explained lower down that different modes like DX or FX in the one camera reveals a slightly different ISO level...

Not if the same FOV is being metered.

also matrix or single point dynamic range effects iso levels.

Again, what is "single point dynamic range"?

 

[bleirer]

There really shouldn't be a difference in exposure. Total light would be different with different size sensors, but light per unit area would be the same no matter the sensor size. Possible reasons for different readings might be one camera is set to 1/3 stop intervals and the other set to 1/2 stop. Or the part of the scene being metered is slightly different with something brighter or darker at the periphery. Or perhaps one camera has a setting such as highlight protection and the other doesn't. Or perhaps different meters calibrated slightly differently.

 

[Ken Miracle]

There really shouldn't be a difference in exposure. Total light would be different with different size sensors, but light per unit area would be the same no matter the sensor size. Possible reasons for different readings might be one camera is set to 1/3 stop intervals and the other set to 1/2 stop. Or the part of the scene being metered is slightly different with something brighter or darker at the periphery. Or perhaps one camera has a setting such as highlight protection and the other doesn't. Or perhaps different meters calibrated slightly differently.

There was discussion above about matrix metering versus "single point dynamic range" not sure what that is. However in FX or DX in something like program or manual with auto iso and all settings are the same and the focal point is the same with a Nikon since metering follows the focus point and you change metering from Matrix, to Center Weighted to Spot you will see changes in ISO and even the resultant size of the image. Your telling the camera to meter on different areas of the image ... if the entire scene was a uniform tone ie. all white or all black then there should be no difference in metering modes but in real world use there will be with varying tones in the image.

 

[O]

Presumably "matrix" refers to matrix metering. But what is this "single point dynamic range"? I don't recall that D850 sold in North/South America has such mode/setting?


Really? With no further qualification? Are you referring to FX vs DX cameras with the MP?


Not if the same FOV is being metered.


Again, what is "single point dynamic range"?

Thank you for your questions, and Yes your correct, better choice of word is metering single point

different modes like DX or FX in the one camera in this case the D850 was used reveals a slightly different ISO level...when switching from FX to DX.

Sorry for any confusion but i took a simple shot using P mode in FX then DX on the one D850 camera then in single point metering then in matrix and watched the ISO numbers change with each different shot.

Hope that helps clear things up a little, welcome any comments or advice.



Sample shot 1 on a D850

In Full Frame the camera will go to F1.8 and 640 ISO, note in single point metering range its 640 iso in Matrix its 500 go figure.

then change the setting in image area to DX mode with mask on, again in P Mode,

Sample shot 2 on a D850

In DX mode the camera will go F 1.8 and 1000 ISO in single point metering range, in matrix its 640 go figure.

My feeling is i noticed DX calls for higher iso than FX using the same camera if light conditions are not using flash, ideal good or sunny conditions

Only an opinion

 

[Ken Miracle]

Thank you for your questions, and Yes your correct, better choice of word is metering single point

different modes like DX or FX in the one camera in this case the D850 was used reveals a slightly different ISO level...when switching from FX to DX.

Sorry for any confusion but i took a simple shot using P mode in FX then DX on the one D850 camera then in single point metering then in matrix and watched the ISO numbers change with each different shot.

Hope that helps clear things up a little, welcome any comments or advice.



Sample shot 1 on a D850

In Full Frame the camera will go to F1.8 and 640 ISO, note in single point metering range its 640 iso in Matrix its 500 go figure.

then change the setting in image area to DX mode with mask on, again in P Mode,

Sample shot 2 on a D850

In DX mode the camera will go F 1.8 and 1000 ISO in single point metering range, in matrix its 640 go figure.

My feeling is i noticed is DX calls for higher iso than FX using the same camera if light conditions are not using flash, ideal good or sunny conditions

Only an opinion

There are two different possibilities that might be what you are referring to as single point metering and they meter differnetly ... the smallest metering area and most "precise" is Spot and the next level up is Center Weighted and the size of the "center" can be adjusted in the D850 even more than in the Z9.