Pentax 645Z vs Phase One IQ 250 vs Hasselblad H5D 50c

[synn]

Surprised that no one posted this here yet:

Pretty nice 2 part video comparison

https://www.youtube.com/watch?v=7yGhKDwfD1Y

https://www.youtube.com/watch?v=30TWJ8bWGmA

[Phil Indeblanc]

Interesting for the body and ergo, lens. The Hass files on the screen looked color rich and nice tone. Just at face value, and not that the P1 or Pentax cannot get the same file in process. But looks like the leaf shutter is the winner, and not so much the digital backs. 

[synn]

Interesting for the body and ergo, lens. The Hass files on the screen looked color rich and nice tone. Just at face value, and not that the P1 or Pentax cannot get the same file in process. But looks like the leaf shutter is the winner, and not so much the digital backs.

Yes, the Hassy files really did look amazing SOOC.
With the sensors being the same, it really is the other aspects of the system that are differentiating the products. Namely, Leaf shutters, post production software etc.

The video does highlight one view point that I have been maintaining for long now and that is; ACR/LR is absolutely not a good choice for RAW development, especially for medium formats. The Pentax software is terrible in terms of UX, but the colors that he got from it were much better than in ACR, even with the embedded profile.

[torger]

Having worked with profiles lately (DCamProf project) my conclusions is that Hassy's Phocus makes the best color which is like 95% realistic and just at sliiiight "look" to it (which I personally think is how camera color should be), Phase One adds a bit too stronger look, often to the yellowish side, and Adobe's default profiles are not that good at all.

Why Adobe's profiles are not good seems to be the way they apply the tone curve. Phase One for example has a carefully tuned dual-curve approach, one user-selectable RGB curve, and one subtle curve (more Lightness based) in the ICC profile itself. Adobe just have their tone curve as a straight RGB-HSV curve in the DNG profile which distorts colors in a characteristic way, in a way that I'm sure the Adobe team think is good, but I don't. This can be compensated for (my DCamProf project does that) but requires large LUTs (my DNG profiles are 1.5 megabytes!).

If I couldn't make my own profiles Hasselblad would be my primary choice. Phocus is indeed ancient, but if you have a Photoshop-centered workflow you don't need much functionality from the raw conversion anyway. Now when I can make profiles and even make Adobe Camera Raw look good, I would choose the Pentax due to price and flexibility. I don't need the leaf shutter function as I'm not a flash photographer.

[synn]

Torger, have you profiled the Pentax yet? If not, it might be worth asking some of the owners here for helping you with files.
Also, I really think you should write to some of the usual photo blogs like Fstoppers, Petapixel and the Phoblographer to get some exposure to your project. I am sure there are people out there who woudl appreciate what it can do for their workflow.

[torger]

I haven't profiled the Pentax. I've profiled my own camera H4D-50, my old Canon, and there's been some early adopters profiling various consumer cameras and as high end stuff as the IQ260. My project hasn't reached version 1.0 yet (but it's close) so I'm staying a bit low for now. As it's command line (like the open source color management system Argyll) it won't attract a huge following in any case. Making a basic profile is still very easy automatic process though so for the majority of users it's quite easy to use.

Tuning one to achieve the optimal subjective look in various conditions is however a difficult manual process which requires a good eye for color. When it comes to tuning look you can easily spend 20+ hours to perfect one profile, and if you want to compete with the "big guys of color", ie Hassy and Phase One you generally need to do some of that. To be confident that I've made a world-class Pentax 645z profile I would practically need to own one to be able to make field tests and fine tune based on that. To just exceed ACR I'm quite sure the automatic process from a basic daylight or flash colorchecker shot would do it though

[torger]

Just in case someone's interested in 645z profiles:

Based on the Imaging Resource image: http://www.imaging-resource.com/PRODS/pentax-645z/645ZhVFAI000100.DNG.HTM
and the workflow outlined here: http://www.ludd.ltu.se/~torger/photography/camera-profiling.html#the_easy_way

I used the 24 patch colorchecker only. Imaging Resource also have the larger CCSG target in their picture, but it's a glossy target which needs very careful shooting setup to minimize glare issues and IR doesn't do that, so it's generally next to unusable for profiling.

I made a DNG profile "in the blind" in 3 minutes (single illuminant D50/flash). To make one for Capture One is a little bit more complex (there's a workflow for that too).

I attached one with the neutral look, and one with a custom look (very close to neutral) but with the following changes:
  - longer rolloff to white in skin-tone range to improve look of high-key portraits
  - shorter rolloff to white in cyan-blue-magenta to improve color of skies
  - slight warmup of midtones and highs in greens and yellows for making sunlit areas stand out more in landscapes
  - slight saturation increase, skin-tones excluded as well as already highly saturated colors
  - slight reduction of green component in oranges to get better separation between greens and reds (for landscapes)
  - compress the gamut towards AdobeRGB

This is a basic demonstration what the look of a DCamProf profile will be. The elaborate workflows will still be very close in look to those automatic ones, so if you don't like the look at all produced by these profiles DCamProf is probably not the tool to use.

If you do studio portraits you would probably in addition to this do some subtle skin tone adjustments

Another common thing to do is to match the tone curve (brightness + contrast) with the camera's own in-camera JPEG tone curve. In this quick-and-dirty profile I just use a default tone curve which may not match the camera. When using auto-exposure it's of course important that the profile will output the brightness and contrast the camera expects, or else exposure will be off.

[torger]

Stealing/borrowing an image from Imaging Resource's gallery:
http://www.imaging-resource.com/PRODS/pentax-645z/pentax-645zGALLERY.HTM

I've attached a comparison between the profiles, Adobe's default, and the two profiles from the previous post. Unfortunately the gallery did not have any good portrait with good light. But anyway this shows the scale of the differences at least.

The girl's blue top becomes highly saturated in that light and clips sRGB but it's dealt with quite fine. What may look like a gradient artifact on the highlight is actually an effect of specular highlights on the textile's texture (seen in the full size image), so you can ignore that.

I don't have a calibrated screen at this workstation so I can't do much color analysis, but I see as much that skin tones are quite different between Adobe's and DCamProf's rendering, and Adobe's seems to be a bit desaturated overall, especially on high saturation colors.

The neutral vs look rendering differences are so subtle that you need to layer them on top and do A/B switch to see what the differences are (it's deliberate), unless you have super-eyes. If you do you'll notice the warmer yellows and greens, overall a very slightly higher saturation, and lower saturation of the brighter parts of the skin due to a different highlight rolloff in that range (which is designed to work well for high key portraits).

[jwlimages]

Just in case someone's interested in 645z profiles: ...

Torger, thank you very much for posting these! I am just starting to look at them, using some landscape images & comparing to a CC Passport profile I was able to make myself (yes, CCP succeeded with Pentax .dng's, twice out of maybe 50 attempts!). I made mine using "noonish" sunlight.

The first thing I see is that both of yours seem a bit smoother & render a bit lower contrast than the CCP ones. Also interesting is the fact that using a virtual copy in Lightroom, I need to lower the "color temp" 400-600K to get an overall White Balance similar to the image with the CCP profile (or the Pentax Embedded .dng profile, for that matter).

The idea of being able to improve on the x-Rite profiles is exciting!

John

[jduncan]

Surprised that no one posted this here yet:

Pretty nice 2 part video comparison

https://www.youtube.com/watch?v=7yGhKDwfD1Y

https://www.youtube.com/watch?v=30TWJ8bWGmA

Just to tell you: I did, but in a comment , long time ago.  He does a good work. Clearly he is a PhaseOne shooter by the way.

He also has this one:
https://www.youtube.com/watch?v=zwS_p_fUsck

The full review is online in Cantonese. He takes a long time to translate them, probably due to his obligations, but he always does and that is very kind.

Best regards,

[Doug Peterson]

Just to tell you: I did, but in a comment , long time ago.  He does a good work. Clearly he is a PhaseOne shooter by the way.

It could be the (very biased) Phase One dealer in me, but I actually think he skipped a large number of advantages for the Phase One platform. But it was a high-level-overview and I guess that's to be expected.

I'd love to see this review redone with an XF since he was using the legacy DF+. But that's also the way with reviews; the moment you publish the landscape of available options changes.

He got one thing 100% right; if you want to know how the differences apply to YOU then the only way to do that is for YOU to shoot with them and make up your own mind. Personally shooting with the systems in question for one hour is better than a hundred hours of armchair reviews and spec-sheet reading.

[jduncan]

It could be the (very biased) Phase One dealer in me, but I actually think he skipped a large number of advantages for the Phase One platform. But it was a high-level-overview and I guess that's to be expected.

I'd love to see this review redone with an XF since he was using the legacy DF+. But that's also the way with reviews; the moment you publish the landscape of available options changes.

He got one thing 100% right; if you want to know how the differences apply to YOU then the only way to do that is for YOU to shoot with them and make up your own mind. Personally shooting with the systems in question for one hour is better than a hundred hours of armchair reviews and spec-sheet reading.

I did not express myself properly, I did not mean that he was being subjective or biased. I mean he has more phase one experience (capture one by example) and also have a good review of Phase stuff.

Best regards,

[torger]

Torger, thank you very much for posting these! I am just starting to look at them, using some landscape images & comparing to a CC Passport profile I was able to make myself (yes, CCP succeeded with Pentax .dng's, twice out of maybe 50 attempts!). I made mine using "noonish" sunlight.

The first thing I see is that both of yours seem a bit smoother & render a bit lower contrast than the CCP ones. Also interesting is the fact that using a virtual copy in Lightroom, I need to lower the "color temp" 400-600K to get an overall White Balance similar to the image with the CCP profile (or the Pentax Embedded .dng profile, for that matter).

The idea of being able to improve on the x-Rite profiles is exciting

I don't think the X-Rite profile or Adobe's DNG Profile editor is that great. The problem is not the target. A CC24 may seem simplistic, but due to the good linearity especially on these new Sony sensors you don't need many patches to get very good accuracy over a large gamut. You can improve accuracy of ultra-high saturation colors using other targets, or if one's into reproduction custom made targets made of the same material as the artwork to copy can improve accuracy, but when it comes to general purpose photography I do believe that you can make a high end profile with just a CC24 target.

The secret of good color for general purpose photography lies elsewhere: 1) when you apply the tone curve, how the base linear colorimetric profile is compensated for the color appearance changing side effects of the curve, and 2) subtle subjective adjustments, and possibly 3) handling extremes well (close to highlight clipping, close to chroma clipping). And well, choice of curve shape has some significant effect too. In the posted example I just had Adobe's default curve, which indeed is quite fine but there are other choices too.

As far as I know X-rite's software does do any curve compensation at all, they just apply the curve on top of a colorimetric profile and let it become what it becomes. Broadly speaking the effect is desirable, a pleasing increase of saturation, so it looks fine at first glance, but for a top notch result more needs to be done. I have put quite some effort into DCamProf to do a better job on that.

The white balance shift is probably due to an unfortunate design choice by Adobe which means that to avoid that one need to copy the ColorMatrix from an existing profile you want to match. Cameras are mediocre at best at estimating color temperatures, so even if two profile designs both use the best techniques they will easily end up with 400-800K different view of what the color temp is. The profile I provided has it's own designed ColorMatrix, but you can copy the existing (it won't affect color reproduction as that is handled by the ForwardMatrix+LUT).

If you get the shift even with the "as shot" white balance, the there's some other issue. It's quite common that profiles are designed with a subjective temperature adjustments, various sorts of warmups are common. This can be added with DCamProf too. For my own Hassy I've chosen to add such a warmup partly to match what the camera expects. The white balance presets on the camera such as "daylight" usually work better if the profile delivers the same warm/cool as the designer that chose the preset expected.

So indeed there are a number of things one can work with from the basic "3 minute profile in the blind" I posted, but a tuned profile will still be overall close in look to that basic one. So it's a good start to like most of what the basic profile does (the rest can then be tuned), if one doesn't like it at all DCamProf is not the tool to use (as fixing will then become an overly difficult task).