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Sigma DP1 Merrill Shots

Malina DZ

Member
Thank you Tan for the compliments.
I just wish to remind forum readers that DP cameras quite often do not produce such clean, free from aberrations files with accurate colors and intense detail.
The more I shoot with dp1m, the more I learn its weaknesses which are induced on the tricky Foveon sensor by the 75° field of view lens design. Unlike dp2m files, the former shows noticeable traces of transverse CA even at f/5.6. CA correction is now turned on in my default conversion process since SPP handles it quiet well.
Green/magenta pattern noise is unpredictable even at iso100 and may color shadows with patches that are difficult to get rid of with color balancing. This issue occurs in dp1m images more often than in dp2m.

The worst offender to dp1m is a stray light. Dp1m 19/2.8 lens is very flare prone. The veiling flare adds a greenish haze that I don't find artistically attractive in any way.


f/5.6, iso160, 1/1250s


f/6.3, iso160, 1/250s

Still, regardless of the above drawbacks that may influence/limit one's composition choice, dp1m can produce files with the accutance my 6D+2/28ZE can only dream about.

Contemporary Art
f/2.8, iso200, 1/30s
 

furtle

Active member
I've just bought a DP1M from Ebay :) Near mint. 28mm equiv is a very useful lens and the camera is small enough to keep in my coat pocket. Alas, not the weather for photos at the moment.
 

ggibson

Well-known member
Fun! I just bought a DP2M to play with myself. Not expecting it to replace my Sony A7r2 by any stretch, but I'm interested to compare the two. The Merrill output seems different enough that it could be worth having for certain occasions/subjects.
 

biglouis

Well-known member
Fun! I just bought a DP2M to play with myself. Not expecting it to replace my Sony A7r2 by any stretch, but I'm interested to compare the two. The Merrill output seems different enough that it could be worth having for certain occasions/subjects.
It would be interesting to see some comparison shots. When I bought an A7R I did some shots against the DP2M and for the first time saw flaws in the DP2M. The A7R definitely bested it at the pixel peeping level. Mind you, in the end it didn't stop me selling the A7R - and I still have the DP2M.

LouisB
 

ggibson

Well-known member
It would be interesting to see some comparison shots. When I bought an A7R I did some shots against the DP2M and for the first time saw flaws in the DP2M. The A7R definitely bested it at the pixel peeping level. Mind you, in the end it didn't stop me selling the A7R - and I still have the DP2M.

LouisB
Unfortunately the camera I received was in worse shape than the auction described, so I ended up returning. I did take a few test shots before it went, but I don't have a great FE lens to compare it with on my A7rII (only my 24-240mm). Here's one shot, some processing done to bring the two images to a roughly similar state... just keep in mind this is far from a studio-controlled comparison:

Sigma at 30mm, f10, 1/250s, ISO 100, cropped about 10% to 13.2MP to match framing
Sony at 38mm, f8, 1/350s, ISO 100, cropped about 29% to 30MP to match framing

Zoomed-out side by side.


And at 1:1


From playing with these files and a few others I took that day, I think the results are pretty similar to what I expected. The Sigma puts up an amazing fight in resolution, starting with only 14.7MP vs. a monster 42MP bayer sensor. Obviously the A7rII is handicapped by the 10x zoom lens and a closer crop, but even so I do think the A7rII is able to out-resolve the Sigma. In a more controlled fight with a prime on the Sony, I have no doubt which would have more resolution. There is, however, something clean and punchy about the Sigma file that I really like.

Color-wise, these two shots can be adjusted to come out pretty similarly overall, but I can see the Sony is picking up some tones in the foliage and on the path where the Sigma does not. I saw this in a couple of other test shots as well where it was clear that the DP2M was weaker in this area. I notice this mostly in reddish hues where the DP2M was either more muted or just producing a too-similar shade of red for two things that looked obviously different in person. This seems to be a quality of the Merrill sensor, and the Quattro is much better at recreating color (even if it gives up some of that "micro-contrast").

I really like the Sigma cameras and sought to pick up a DP2M to give me a taste of "something different". It can produce some really amazing pictures, especially at around $400 used. Since I sent this one back, I'll have to think again about whether I want to pick up another one, try a DP3M maybe, or even a DP2 Quattro. I tried the DP2 Quattro a couple years ago when it came out (part of a Sigma loaner program) and compared it to my A7 at the time. I guess I keep going back and forth about whether the "foveon magic" exists or not, or is even worthwhile if it's there. Since I have the Sony already, maybe it'd be better to just spend the money on another lens there, hmm? I do appreciate the small size of the DP2M, and maybe Sigma will make my decision easy and come out with an improved Quattro camera that can actually fit in a pocket like the old DP2.
 

Stoneage

Member
Color-wise, these two shots can be adjusted to come out pretty similarly overall, but I can see the Sony is picking up some tones in the foliage and on the path where the Sigma does not. I saw this in a couple of other test shots as well where it was clear that the DP2M was weaker in this area. I notice this mostly in reddish hues where the DP2M was either more muted or just producing a too-similar shade of red for two things that looked obviously different in person. This seems to be a quality of the Merrill sensor, and the Quattro is much better at recreating color (even if it gives up some of that "micro-contrast").
In my opinion there are two reasons for this:
1. The extra micro contrast of the Merrills work against subtile color gradation. The information is there, but it's hidden behind very dark and bright "spots". Lots of micro contrast does grey out the specific area.

2. At the default NR position, SPP does some chroma noise reduction to prevent color blotching. This can desaturate very faintly saturated parts in the image.

You can get a very different, and kind of quattroesque look by using the monochrome mode as luminance layer.

I showed this in an other forum with a DP Merrill file that a user provided:
On the left side you see what you usually get with the DP Merrills with default settings. On the right side i used a SPP monochrom conversion as luminance layer.
Only by adding this layer, the "hidden" colors suddenly pop out.
I don't say it looks better, but it is definitely a method that can be useful sometimes. Of course the amount can be adjusted by using more or less opacity.






Stoneage
 

ggibson

Well-known member
Wow, really interesting. I'm not sure what to do to try out this technique. Do you have a link to the other forum where you explained?
 

Stoneage

Member
Wow, really interesting. I'm not sure what to do to try out this technique. Do you have a link to the other forum where you explained?

It's very simple, and i mostly use it for smoother skin tones, as skin can sometimes look a bit harsh with the DP Merrills.

1. Convert a color image in SPP to your taste and save it as TIFF
2. Convert the same image in the monochrome mode. (this layer will be the luminance layer, or "rendering" layer.)
In the monochrome mode i always turn off luminance noise reduction. Be sure no parts are blown out. Save it as TIFF also.
3. Open both images in Photoshop and blend them together using Luminosity layer mode.

I'm not sure if there is a benefit in this sample, but good enough to explain:



Same method for smoother skin:


There are endless variations with this method depending how you process the monochrome image (for example by using the blue layer) or by playing with the opacity in Photoshop.
Or by just using specific parts from the Monochrom layer. (only the skin for example)

Hope it helps.

Stoneage
 

Malina DZ

Member
Thank you for the tip Stoneage! This technique provides pleasant results for quick skin smoothing with less detail loss than SPP Luminance NR setting of 0.75! :cool:
 

xpatUSA

Member
In my opinion there are two reasons for this:
1. The extra micro contrast of the Merrills work against subtile color gradation. The information is there, but it's hidden behind very dark and bright "spots". Lots of micro contrast does grey out the specific area.

2. At the default NR position, SPP does some chroma noise reduction to prevent color blotching. This can desaturate very faintly saturated parts in the image.

You can get a very different, and kind of quattroesque look by using the monochrome mode as luminance layer.

I showed this in an other forum with a DP Merrill file that a user provided:
On the left side you see what you usually get with the DP Merrills with default settings. On the right side i used a SPP monochrom conversion as luminance layer.
Only by adding this layer, the "hidden" colors suddenly pop out.
I don't say it looks better, but it is definitely a method that can be useful sometimes. Of course the amount can be adjusted by using more or less opacity.






Stoneage
Interesting. Those images remind me of looking at some Quattro images in RawDigger that looked foggy because I had the black level set at zero but the lowest level in the Quattro images was much higher than that. By setting the black level to "auto", the images sprang into life just like the ones above!

rgds,

Ted
 
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