p.30 #1 · Sigma DP2 Merrill: Have any of you tried it?
sector99 wrote:
SIGMA is catching a lift from their new cameras and one can see them offering a CSC mirrorless body product. If they are smart SIGMA will first offer an M-Mount, then an APS-C monochrome sensor (FOVEON without filters) in order to threaten the Leica MONOCHROM body.
An M-mount body won't be happening with the current generation of sensor technology. Current Foveon sensors are prone to severe color shifts due to varying light angles from lenses; the majority of interesting M-mount lenses would produce fairly unusable results. Only SLR designs (where some limitations on light angles are enforced by the requirement to clear the mirror) or specially designed extra-telecentric lenses (e.g. DP1M, DP2M lenses, which are different from "typical" rangefinder mid/wide designs) can produce acceptable results. One can hope that further technology developments (improved microlens arrays like Leica has developed? fancy shaped silicon like the recently discussed Sony patent?) will eventually make this possible, but Sigma can't just slap their current sensors in an M-mount body with useful results.
Also, what's a "FOVEON without filters"? In the Foveon design, the sensor silicon is the only filter. A "Foveon without filters" (i.e. without silicon) would be the Emperor's New Clothes of sensors, capable of producing the finest ZEROCHROM images for devoted fans of minimalism
p.30 #3 · Sigma DP2 Merrill: Have any of you tried it?
sector99 wrote:
If they are smart SIGMA will first offer an M-Mount, then an APS-C monochrome sensor (FOVEON without filters) in order to threaten the Leica MONOCHROM body.
If Sigma is smart, they will go after a much bigger market than that. The M market is tiny compared to most other segments.
p.30 #4 · Sigma DP2 Merrill: Have any of you tried it?
OK, here's an exposure push test series to check for shadow desaturation.
Taken under (icky) compact fluorescent lighting, with quick "custom" gray card WB. SPP "neutral" color settings, NR defaults (middle setting). All at ISO 100, varying shutter speed in 1-stop increments, then pushing results in post (first 2 stops in SPP, rest in Aperture) to keep lower-left white square at fairly constant luminance.
No attempt was made, beyond the gray card WB, to get colors "correct" in this, which might have been futile under these lighting conditions because color accuracy was pretty awful to start with.
Color saturation never completely goes away, but it drops pretty steeply at -4+ stops under. There is definitely also a strong nonlinear "S-curve" tonal adjustment being applied (as Tariq has noticed), based on the increasingly large amounts I needed to push the files (compared to the shutter speed, especially at -4 and beyond) to keep constant exposure; the bottom row of gray patches also shows a steeper fall to black at lower exposures.
p.30 #5 · Sigma DP2 Merrill: Have any of you tried it?
For comparison, here are ISO1600, 3200, and 6400 versions for the exposure -4, -5, -6 shots (increased in-camera ISO instead of post-processed pushed ISO100). These do better than the pushed versions for retaining color, and don't need additional pushing beyond nominal to correct for SPP's exposure curve. The DP2M is definitely not an "ISO-less" camera like the D800/Sony sensors.
p.30 #6 · Sigma DP2 Merrill: Have any of you tried it?
Another issue in the exposure push series, increasingly visible in the -4, -5, and -6 shots, is how the RAW developer is segmenting the image into different blobby regions, with sharply defined borders, to guess what the color is in each. I suspect that (and this would require further testing) color reproduction at low exposure falls off even more quickly for areas with high spatial frequency color changes (as opposed to the uniform test chart patches, where the algorithm can try to average the color response over a larger region).
p.30 #7 · Sigma DP2 Merrill: Have any of you tried it?
mpmendenhall,
Thank you for the interesting and hard work.
Your findings confirm the day to day shooting sofar with the DP2M.
How much this is an image quality issue very specific for this camera i am not sure. We have to keep in mind that the new Nikons with Sony sensors are state of the art at this time regarding this subject.
Sigma burries the nasty artifacts in the toe of the tone curve, not intended to get extracted per raw converter.A valid decision but hopefully things can improve in future Foveon developements.
p.30 #9 · Sigma DP2 Merrill: Have any of you tried it?
Here is the ISO100 image re-processed in SPP with "Fluorescent" white balance, followed by color correction (46C+30M) to the lower-left patch, instead of the "custom" gray-card WB used in the above sequence. Still "neutral" color style. It's not perfect, but a whole lot better than the badly under-saturated "custom" WB version. Lesson learned: because color reproduction is a much more complicated process for DP2M images than just getting the gray point correct, "custom" WB with a gray card under "adverse" lighting (probably anything off the regular outdoor/daylight continuum) is likely to be unhelpful. The built-in "closest" camera WB setting, even if the gray point needs significant adjustment, provides a better starting point.
p.30 #11 · Sigma DP2 Merrill: Have any of you tried it?
carstenw wrote:
But the reds and oranges look brown...
Like I said, it's definitely not perfect --- far from it --- but a better starting place than the really horrible color reproduction produced from the gray card "custom" white balance. From here, one has a chance of tweaking colors to get a bit closer to reality.
p.30 #12 · Sigma DP2 Merrill: Have any of you tried it?
Nothing special about the photo, although I think the sigma did a nice job on the colors for what it was, just a snap shot in our local safeway. Anyone pay over $6 for a tomato before?
p.30 #13 · Sigma DP2 Merrill: Have any of you tried it?
And now, for everyone's daily dose of "WTF, SPP?," here's a 100% crop from an ISO 1600 file set to Monochrome in SPP.
If you look closely enough, the "monochrome" pixels are in color (red and green noise patterns). Yes, it's like that in the original TIFF16 output by SPP, not just this JPG crop. WTF, SPP?
p.30 #14 · Sigma DP2 Merrill: Have any of you tried it?
It's time for a visit to flickriver "dp2 merrill". Select "Interesting" in the search window.
Spend some time there and discover the truth about SIGMA DP2M color for yourself. No color "Checkers" needed to "Explain" what you can see with your own eyes. No imaginary color in monochrome images either.
Just 12,399 images taken by real photographers displayed against a black flickr background.
You want bokeh? You want spatial resolution? Your want vibrant color? You want it in your coat pocket?
You want to match FF DSLRs?
Some experts say you can do all of that––with a little determination.
I'm not shilling for SIGMA here––just changing the subject to reality in images.
The Sigma DP1M images appear as if a curve has been applied which had the effect of increasing mid tone contrast at the expense of loosing shadow detail (think S-curve). The effect can look really good overall but I think I would prefer having control over creating that look rather than it being the default.
Not just an S curve.. it looks like the same result as duplicating the image as a layer, changing it to Overlay, Soft Light or Hard Light and applying High Pass filtration to that layer (or to some degree, the Clarity slider in LR).
p.30 #16 · Sigma DP2 Merrill: Have any of you tried it?
sector99 wrote:
What Mr. Gilbran's examples (Just ABOVE) clearly reveal to me is (1) better spatial resolution as evidenced in blades of grass against the light grey path (2) better contrast AND spatial resolution on the fire hydrant and (3) a more realistic appearance in shadow detail for the SIGMA DP Merrill images vs. the NIKON D800E images.
As for the color checker/Lightroom examples above I'm far less sanguine over any color channel weaknesses since these examples aren't from camera RAW results. the comment that SIGMA is attempting to "Hide noise" is pejorative in nature and as such should be ignored on its face.
As for the known Bayer mosaic limitations, modern photographers have been diverted from the truth over time that the Bayer methodology inherently reduces per pixel spatial resolution and with an anti-aliasing filter further lowers the effective sensor resolution. In other words 24 mega pixels isn't what it seems.
SIGMA has, with Fuji's X-Trans filter-reducing mosaic inventions, placed increasing pressure on conventional Bayer/AA sensor technology.
The market leaders are now reduced to adding "Features" like PERSISTENCE (SONY's new RX1 6 frame stacked noise reducer). Never mind this trick was first used in the early 1900's to stack film negs at Lowell Observatory while studying Mars. Talk about hiding noise!
SIGMA is catching a lift from their new cameras and one can see them offering a CSC mirrorless body product. If they are smart SIGMA will first offer an M-Mount, then an APS-C monochrome sensor (FOVEON without filters) in order to threaten the Leica MONOCHROM body.
Life is good for those wanting more truth in sensing coupled with jacket-pocket cameras....Show more →
Sony seems to be well aware of the shortcomings of Bayer sensors. They have a patent on a foveon alike technology. Outdated Bayer technology is a cash cow, and as long as customers are crying for more mp instead of image quality, there is little incentive to invest in new production facilities and technologies. http://www.sonyalpharumors.com/next-sony-foveon-alike-patent/
p.30 #17 · Sigma DP2 Merrill: Have any of you tried it?
rscheffler wrote:
Not just an S curve.. it looks like the same result as duplicating the image as a layer, changing it to Overlay, Soft Light or Hard Light and applying High Pass filtration to that layer (or to some degree, the Clarity slider in LR).
p.30 #18 · Sigma DP2 Merrill: Have any of you tried it?
glacierpete
To be sure camera cattle pine for more Bayer fuzz. However, the masses sought range finders too––until the SLR revealed a better path. As always the bleeding edge users will blaze a new trail and I suspect the Merrills will be their weapons of choice.
It's the option of a slightly better detection scheme combined with a clear convenience package that will start to erode the leader's dominance.
A good test can be seen in the looming SONY RX1's release sales. The CZ lens is good, the package is smallish.
But now one can have two cameras (DP1M & DP2M) each with competing resolution to the RX1 for $800 less. One for each jacket pocket. Each technology prints comparable 20X30s.
One could even dispense with the DP1M and do smallish panos with the DP2M for wides.
To be fair the SIGMAS lack a built-in fill flash and are slower in AF. However the lure of Bayer & AA Free capture is strong.
p.30 #20 · Sigma DP2 Merrill: Have any of you tried it?
The major issue with comparing the Sigma DP Merrills to the Sony RX1 is in overall utility. Throw in low light and/ or artificial light sources into the mix and the Sigma's are going to suck big time. So, the equivalency only holds up in bright, daylight type scenarios.
