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FWIW sdQ/DP2M Comparison

scho

Well-known member
One shot each, tripod mounted ISO 100 f/8. 18-35/1.8 @ 31mm on the sdQ. Same SPP 6.4 processing settings (sharpening -0.7, fill +0.3, rest 0) for each exported tifs to LR and custom WB on 3rd gray patch in the Colorchecker chart. No sharpening or clarity adjustments. Click for full size jpegs.

sdQ



DP2M

 

ggibson

Well-known member
Thanks for sharing. What's your take?

DP2M looks sharper in a lot of places to me, although pretty close when comparing the blue potted plant in the middle. Might be just lens differences as to sharpness elsewhere? SDQ has a bit brighter exposure at the same settings.

I like that little sunburst on the SDQ :D
 

scho

Well-known member
Thanks for sharing. What's your take?

DP2M looks sharper in a lot of places to me, although pretty close when comparing the blue potted plant in the middle. Might be just lens differences as to sharpness elsewhere? SDQ has a bit brighter exposure at the same settings.

I like that little sunburst on the SDQ :D
Yes, I think that the DP2M looks slightly sharper, but I could easily make some minor tweaks to clarity and achieve a similar look with the sdQ image. Neither had any adjustment to clarity or sharpness beyond the SPP 6.4 -0.7 sharpness setting for both.
 

scho

Well-known member
I removed the dust shield to see how this camera responds to full spectrum light and potential for IR imaging using 850nm IR pass filter. Still need to do some work making custom camera profiles and WB settings.

18-35 with no IR cut


Same, processed as monochrome in SPP 6.4


70 Macro monochrome processing
 

ggibson

Well-known member
Wow, those are some wild colors in the first image. Looking forward to seeing some fully processed IR shots.

Was it easy to remove the dust cover?
 

scho

Well-known member
Wow, those are some wild colors in the first image. Looking forward to seeing some fully processed IR shots.

Was it easy to remove the dust cover?
Dust cover is easy to remove and replace (pg 153 of manual), but you should have a pair of tweezers/forceps, preferably with non-slip rubber/plastic tips (don't want to slip and scratch the filter). I'm used to working with modified bayer sensors for IR imaging where you first make custom WB settings for the filters you want to use and then optionally, make dng camera profiles for initial conversion processing. That type workflow simply does not apply with the quattro - or at least I do not know how to do it. I have have been unable to make a custom WB setting in the camera by shooting (with and IR pass filter on the lens) a grey/white/magenta/or green target to get a neutral WB. Camera reports error and asks you to repeat the process. So far the only workable approach has been to shoot with any standard WB setting (eg. incandescent) and then do a monochrome conversion in SPP 6.4. Not ideal and minimal in camera control, plus you are trying to see through and focus with the blinding red color cast blurring all detail. Much easier with my FS A7r.
 

biglouis

Well-known member
Carl

Thanks for taking the time to post these and provide information about the photographs.

I see the same level of sharpness or rather slight softness at 100% between both cameras - which surprises me as I have always felt my DP2M is sharper at 100% than my DP0Q.

LouisB
 

xpatUSA

Member
Yes, I think that the DP2M looks slightly sharper, but I could easily make some minor tweaks to clarity and achieve a similar look with the sdQ image. Neither had any adjustment to clarity or sharpness beyond the SPP 6.4 -0.7 sharpness setting for both.
I took the liberty of linking to your post from DPR. See:

https://www.dpreview.com/forums/post/58168897

In a previous thread there, someone had commented on a 'filmy' appearance in some sd Q images on flikr and your Q shot showed that effect slightly.

My thread there isn't going all that well but you might might find some points to be of interest.

Nice comparison, by the way, well done. It is so common to see camera comparisons done with different scenes, different days, different lighting and even different processing culminating with deeply meaningful one-liners like "the M is better than the Q" ;)
 

xpatUSA

Member
Dust cover is easy to remove and replace (pg 153 of manual), but you should have a pair of tweezers/forceps, preferably with non-slip rubber/plastic tips (don't want to slip and scratch the filter). I'm used to working with modified bayer sensors for IR imaging where you first make custom WB settings for the filters you want to use and then optionally, make dng camera profiles for initial conversion processing. That type workflow simply does not apply with the quattro - or at least I do not know how to do it. I have have been unable to make a custom WB setting in the camera by shooting (with and IR pass filter on the lens) a grey/white/magenta/or green target to get a neutral WB. Camera reports error and asks you to repeat the process. So far the only workable approach has been to shoot with any standard WB setting (eg. incandescent) and then do a monochrome conversion in SPP 6.4. Not ideal and minimal in camera control, plus you are trying to see through and focus with the blinding red color cast blurring all detail. Much easier with my FS A7r.
Yes, I've found it virtually impossible to set a full-spectrum Custom WB on my SD10 or SD14 but the SD1M will take it most of the time. So, I use Incandescent on the earlier cameras.

A thought occurs that the so-called 'UniWB' might be worth a try:

GUILLERMO LUIJK >> TUTORIALS >> UNIWB. MAKE CAMERA DISPLAY RELIABLE

I did it on an SD10 long ago, and it does involve shooting a wine-colored target on the monitor (but with the dust cover in place). As you may know, UniWB attempts to make the camera histogram show raw levels.

From your post, I've just realized that Custom WB does affect the camera LCD and histogram, so there's an area for further experiment in order to help with assessing what they are telling you, which is mostly lies once you've got the 720nm on the lens ;)
 

scho

Well-known member
Yes, I've found it virtually impossible to set a full-spectrum Custom WB on my SD10 or SD14 but the SD1M will take it most of the time. So, I use Incandescent on the earlier cameras.

A thought occurs that the so-called 'UniWB' might be worth a try:

GUILLERMO LUIJK >> TUTORIALS >> UNIWB. MAKE CAMERA DISPLAY RELIABLE

I did it on an SD10 long ago, and it does involve shooting a wine-colored target on the monitor (but with the dust cover in place). As you may know, UniWB attempts to make the camera histogram show raw levels.

From your post, I've just realized that Custom WB does affect the camera LCD and histogram, so there's an area for further experiment in order to help with assessing what they are telling you, which is mostly lies once you've got the 720nm on the lens ;)
Yes, I've used the UNIWB approach before so I'll give that a try with the sdQ and see if it works. Red channel blows out easily on the sdQ with the cut filter removed so I don't know if the in camera custom WB will be able to tame that problem.
 

scho

Well-known member
I took the liberty of linking to your post from DPR. See:

https://www.dpreview.com/forums/post/58168897

In a previous thread there, someone had commented on a 'filmy' appearance in some sd Q images on flikr and your Q shot showed that effect slightly.

My thread there isn't going all that well but you might might find some points to be of interest.

Nice comparison, by the way, well done. It is so common to see camera comparisons done with different scenes, different days, different lighting and even different processing culminating with deeply meaningful one-liners like "the M is better than the Q" ;)
The "filmy" appearance can easily be fixed with a little clarity adjustment. The other problem (actually with all of my sigma cams) is grayish greens that is also easily fixed using the custom color adjustment in LR. Here is the test sdQ image again with some additional PP in LR.

 

xpatUSA

Member
The "filmy" appearance can easily be fixed with a little clarity adjustment.
Indeed, but what was good about your OP was the lack of post-processing which clearly illustrated that 'filmy' effect for them people over there :)

The other problem (actually with all of my sigma cams) is grayish greens . . .
. . . with the possible exception of SD14s which crank out some "serious" greens (well, the three I've had do anyway).
 

ggibson

Well-known member
Yes, I think that the DP2M looks slightly sharper, but I could easily make some minor tweaks to clarity and achieve a similar look with the sdQ image. Neither had any adjustment to clarity or sharpness beyond the SPP 6.4 -0.7 sharpness setting for both.
Looking again, I think you're right. If I enlarge the DP2M image, the sdQ shot looks sharper (especially on the PP'd version). I'm just comparing the stationary items on the bench, since the background could have some slightly different focus.
 

scho

Well-known member
Looking again, I think you're right. If I enlarge the DP2M image, the sdQ shot looks sharper (especially on the PP'd version). I'm just comparing the stationary items on the bench, since the background could have some slightly different focus.
Correct. Focus point was the ColorChecker chart on the bench, so background foliage is slightly OOF and DOF range.
 

TN Args

New member
Yes, I think that the DP2M looks slightly sharper, but I could easily make some minor tweaks to clarity and achieve a similar look with the sdQ image. Neither had any adjustment to clarity or sharpness beyond the SPP 6.4 -0.7 sharpness setting for both.
Sigma sdQ vs DPM.jpg

Hi, thanks for the interesting thread. If I may waste my first post with a small suggestion? :eek:

Comparing the targets from your two images, note how the L values of the grey patches have a wider range with the M than the Q. The Q therefore has a flatter tonal curve (generally a good thing, as it allows a greater range of EVs on the same RGB map, but minimally-processed raw files will tend to look more flat). So, instead of Clarity, perhaps gently tweak the Contrast or Tone Curve to suit (of either image, but I assume you want the Q image to bite more, to taste). This is directly tackling the root cause of the visual difference, whereas Clarity makes neighbour-dependent pixel adjustments and changes the image entirely.

Also, these L values confirm an earlier comment in this thread that the Q image has higher exposure (of mid tones). So, reducing brightness of the Q image, until the mid tones match in brightness with the M mid tones, might also increase its apparent contrast (deeper blacks) and apparent saturation -- hence also accounting partially for the difference in the look of the images.

P.S. grey patches 3 and 4 of the M image have quite a strong colour drift. Assuming it is not the camera, could it be that the lighting was slightly dappled or variant across the colour cards? Perhaps it is just the proximity of green leaves to the card -- but it affected the M image more.

cheers
Arg
 
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