Luminous Landscape Forum
Equipment & Techniques => Medium Format / Film / Digital Backs – and Large Sensor Photography => Topic started by: eronald on December 14, 2013, 07:18:43 pm
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Hi,
I just retrieved a C1 profile which I made for the P30/P30+/P40/P45+. In fact it is for the P30+ as its name indicates, but should also work on the other models.
The file is called P30+DaylitePortraMedSat.icc
This is and edited profile, with a boosted luminance curve, reduced saturation, and a reduction of the magenta facial skin cast which is sometimes problematic for certain images taken with digital cameras. It is suitable for portraits and people images, not shots of things.
To install the profile on windows machines, I think you just doubleclick on it - tell me otherwise. On Macs, the profile should be copied to the folder YourHomeName/Library/ColorSync/Profiles after which you restart C1 and you will find it in the list of profiles under "Other".
Here is the download link (https://dl.dropboxusercontent.com/u/93354707/P30%2BDaylitePortraMedSat.icc). Test at your convenience. Please paypal me the retail price of a decent filter(edmundronald at gmail dot com) if you use this for your work.
Edmund
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Hi Edmund,
Would it be used with 'film curve' or 'linear response'?
Best regards
Erik
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Hi Edmund,
Would it be used with 'film curve' or 'linear response'?
Best regards
Erik
With whatever you prefer, but usually some film curve eg. standard or high contrast.
It is similar in use to any profile supplied by C1, except some "look" aspects have been baked in, according to my own aesthetics.
There are other versions with other "looks", I'll find them when I can.
I made this years ago, when I was heavily into camera profiles and profile editing, and in fact it was used by some guys on this forum; I assumed people had all moved on, but in fact I just realized the same backs and sensors are still floating around, so it might be useful to some.
Edmund
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Hi Edmund,
Thanks for your efforts!
Unfortunately, C1 and I make no friends, it seems.
Best regards
Erik
With whatever you prefer, but usually some film curve eg. standard or high contrast.
It is similar in use to any profile supplied by C1, except some "look" aspects have been baked in, according to my own aesthetics.
There are other versions with other "looks", I'll find them when I can.
I made this years ago, when I was heavily into camera profiles and profile editing, and in fact it was used by some guys on this forum; I assumed people had all moved on, but in fact I just realized the same backs and sensors are still floating around, so it might be useful to some.
Edmund
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Erik,
If you are using a Phase back, I very, very strongly recommend C1.
The use is free with their backs - just switch it into DB mode when it asks for a license.
Edmund
Hi Edmund,
Thanks for your efforts!
Unfortunately, C1 and I make no friends, it seems.
Best regards
Erik
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Hi Edmund,
I have a payed for license for Capture One, so cost is not the issue for me. I have three real issues and a few other ones:
1) My workflow is Lightroom. Parametric workflow. I could switch to Capture One but that means reprocessing 75000 images.
2) I cannot get the images I want with Capture One. OK, I have worked with Lightroom since 2006, so I have a long experience. Wit C1 one I have something like eight months of reluctant experience.
3) Capture One is just incomprehensible. Hard to relate controls to physics. Lightroom is similar in a sense but they make a better job. Jeff Schewe and Eric Chan are good at explaining Lightroom. I don't feel that Phase One has that good level of communication.
4) Lightroom can work with calibration workflow, based on test targets and math. Capture One makes a mess of it. LR has Adobe DNG Profile editor, Color Checker Passport software and QPcard software. Does C1 has any profiling software available? I understand you may use Argyll, but I got the impression that C1 ICC profiles are a mess.
5) Capture One doesn't really support DNG or any other open format whatever that may be. I am strongly against proprietary data formats.
6) I feel the user interface in C1 is horrible. It can be configured in many ways, I know, but I want something that is not configurable but works. Try supporting someone who has an entirely different setup than yours, possibly in another language and you get the idea. Why is saturation grouped together with exposure?
7) I don't really feel good about Phase One. Expensive products, lot of marketing but I don't feel they deliver. The P45+ I have has been around for six years or so. It delivers lots of detail compared to my Alpha 900, which is a pair years younger, but it also delivers lots of artefacts. The artefacts are a downside. They could have added an OLP filter and lost some edge contrast, but Phase One saved a thousand Dollar or two, and gave us aliasing artifacts. Noisy shadows. I am not upset with my purchase, it was what I have expected and that is what I got.
No mistake, I like my P45+ and Hasselblad 555 ELD. I like both camera and the back. I also like the Zeiss lenses. The area where MF, Phase One, P45+ and Zeiss delivers is sharpness, not always but mostly.
Look at the two images below. Left side is what I achieved in C1 with 1/2 hour work. Right side is LR5.3 without adjustment except setting white balance and choosing the QPCard profile, all sliders at zero.
Sorry for getting agitated, it just that C1 provokes a lot of feelings, none of which positive. That said I see a few advantages in C1, processing is faster and it produces less aliasing artefacts than LR.
Best regards
Erik
Erik,
If you are using a Phase back, I very, very strongly recommend C1.
The use is free with their backs - just switch it into DB mode when it asks for a license.
Edmund
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4) Lightroom can work with calibration workflow, based on test targets and math. Capture One makes a mess of it. LR has Adobe DNG Profile editor, Color Checker Passport software and QPcard software. Does C1 has any profiling software available? I understand you may use Argyll, but I got the impression that C1 ICC profiles are a mess.
Not a mess at all. Capture One supports the universal ICC format, for input, editing, proofing, and output - rather than a proprietary or closed calibration system. Any software that can generate or edit an ICC profile can be used with C1.
7) I don't really feel good about Phase One. Expensive products, lot of marketing but I don't feel they deliver. The P45+ I have has been around for six years or so. It delivers lots of detail compared to my Alpha 900, which is a pair years younger, but it also delivers lots of artefacts. The artefacts are a downside. They could have added an OLP filter and lost some edge contrast, but Phase One saved a thousand Dollar or two, and gave us aliasing artifacts. Noisy shadows. I am not upset with my purchase, it was what I have expected and that is what I got.
No mistake, I like my P45+ and Hasselblad 555 ELD. I like both camera and the back. I also like the Zeiss lenses. The area where MF, Phase One, P45+ and Zeiss delivers is sharpness, not always but mostly.
Phase One's choice to omit an AA filter (along with every modern digital back other than the ZD) was most definitely not to save money. I've probably had two conversations with clients about artifacts in P1 files in the last year – on the opposite side I've had dozens about the crispness and detail.
The success of the D800E (to the relevant market) to me vindicates the AA-or-not argument in the high end of photography.
So in summary you're happy with your purchase of a back from 2007, love that you can use a classic camera system with it, and wish to keep the back (from other posts), but find that it "doesn't deliver". And you hate aliasing, but continue to use software which systematically produces artifacts more than the alternative. No one says we have to be creatures of logic :P.
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Hi Erik,
You are a Phase One customer and perfectly entitled to publish your opinions. Many of which I agree with, actually.
When it comes to calibration, Phase One use the ICC format, and Adobe used a novel description, DCP files are the DNG profiles, I believe. As an independent member of the ICC I have appreciated the wide array of tools available for a long time for the ICC format, especially since Kodak who invented the Bayer array and much of the technology also pioneered all these matrix-shaper models, and created the first tools. All the tools necessary for editing DNG profiles are not really available outside Adobe, so I would need to create them before I could work as well with their software. I have had various discussions at various times with people at Adobe, including a pretty noisy 15 minutes or so with Thomas Knoll, and the upshot I guess is that they think everyone else is an idiot, and I think they're pretty smart but their results are not as good as they should be, although they are steadily improving. One reason for such smart people arriving at suboptimal results initially is ALLEGEDLY that quite hypothetically quite a few large corporations in the camera industry with well-founded expertise may have been pretty upset with them, and therefore they might have received less help than one would expect from some of the people who make cameras and know them best.
Phase One has the advantage of knowing *their own* cameras really well, and being able to optimize their software and their cameras to work together. I consider C1 to be VERY good in conversion quality, and in many ways superior to Lightroom. The C1 profiles for their own backs are probably exactly what they want them to be; they are not snobbish and know perfectly well that this is open to interpretation. Some of their profiles for third party cameras could be substantially improved. Years ago they asked me to do a bunch of 3d party camera profiles for them, because they had seen my work, and they knew I had industry access and backing. I asked them to sell me a camera at dealer cost (I liked the product), and hold me legally harmless if there were any issues with the profiles and third parties, as I cannot afford legal costs. They refused *both* these requests, and so I never worked with them on this: Request 2 was the deal-breaker. I have since owned a Phase back and it was in many ways a good product, and in some ways problematic, and Phase was neither more nor less difficult to deal with as a customer than any other camera company.
Edmund
Hi Edmund,
4) Lightroom can work with calibration workflow, based on test targets and math. Capture One makes a mess of it. LR has Adobe DNG Profile editor, Color Checker Passport software and QPcard software. Does C1 has any profiling software available? I understand you may use Argyll, but I got the impression that C1 ICC profiles are a mess.
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Hi,
QPCard software can generate ICC profiles but does explicitly not support C1, C1 one can read the profiles but they just result in a mess. Please recommend a calibration software, that generates ICC profiles for C1 from a calibration card at reasonable cost. For Lightroom there are three programs that are actually free.
This thread my offer some insight (Please note that EsbenHR is a Phase One employee working on that stuff): http://www.luminous-landscape.com/forum/index.php?topic=82891.0
Well, the AA-filter for the ZD was at $3000 last time I checked and the IR filter was $1000. Let's put it this way, any image I have shot that is correctly focused at f/8 has some aliasing artefacts. They may be subtle, but they are there. I know there is a moiré filter, but that is not at all subtle. Stopping down to f/16 or bad focus reduces the problems.
The aliasing actually produces fake detail. It can be hard to separate from real detail. What I see most frequently is color aliasing artefacts, see below.
I have written an article about it: http://echophoto.dnsalias.net/ekr/index.php/photoarticles/78-aliasing-and-supersampling-why-small-pixels-are-good
I like the back. It delivers on sharpness and resolution but it fails to deliver on shadow noise. The shadow noise issue is not to bad, it is just below the threshold that matters, I don't have the confidence to pull shadow detail as on the Sony Alphas. I don't know how I feel about colour accuracy. Just as an example, you say that it works with any ICC profile. The topic I referred to indicates that generating ICC profiles for P1 is far from trivial. I considered selling it, but I really like it from many aspects. What I don't like is yellowish greens, aliasing, noise and Capture One. The last problem is easily solved, I just use Lightroom instead.
I also enclose an example. The statue is processed in C1 (to the left) and LR5.3RC to the right. In LR I just set a profile I generated with QPCard software (at zero cost except the QPCard), I have not moved a single slider. Not even exposure. I spent something like half an hour producing the left image.
Sorry I am a bit aggressive, but trying to use C1 makes me loose my temper.
I can also mention that Chris Barrett posted some sample images using IQ260 compared to his new Sony A7r. As expected the IQ260 was much sharper than the Sony, even on a pr pixel basis, but the image was excessively noisy. True Chris Barrett was using ISO 100 (instead of ISO 50) but that also applied to the Sony (which also has ISO 50 as minimum). The IQ260 image was underexposed, but Chris said that more exposure caused washed out highlights. I downloaded those raw files, and quite clearly the Sony image had more shadow detail. More importantly, normal detail was noisy on the IQ260. At least in my case I got less noise with LR 5.3 than with C1.
See this thread: http://www.luminous-landscape.com/forum/index.php?topic=84842.0
Best regards
Erik
Not a mess at all. Capture One supports the universal ICC format, for input, editing, proofing, and output - rather than a proprietary or closed calibration system. Any software that can generate or edit an ICC profile can be used with C1.
Phase One's choice to omit an AA filter (along with every modern digital back other than the ZD) was most definitely not to save money. I've probably had two conversations with clients about artifacts in P1 files in the last year – on the opposite side I've had dozens about the crispness and detail.
The success of the D800E (to the relevant market) to me vindicates the AA-or-not argument in the high end of photography.
So in summary you're happy with your purchase of a back from 2007, love that you can use a classic camera system with it, and wish to keep the back (from other posts), but find that it "doesn't deliver". And you hate aliasing, but continue to use software which systematically produces artifacts more than the alternative. No one says we have to be creatures of logic :P.
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Erik,
Three names at random for programs generating camera profiles are i1Profiler, Basiccolor Input, and the pervasive and free Argyll.
Iliah has a simple wrapper for Argyll called MakeInputICC. (http://photofeedback.blogspot.fr/2013/07/iliah-borgs-makeinputicc-camera.html)
However it must be said that the practicalities of camera profiling are really difficult; It may take considerable effort to get useful results. In "normal user" hands, the software will resolve difficulties for a given setup and lighting conditions, but rarely yield a good general purpose profile.
Hi,
QPCard software can generate ICC profiles but does explicitly not support C1, C1 one can read the profiles but they just result in a mess. Please recommend a calibration software, that generates ICC profiles for C1 from a calibration card at reasonable cost. For Lightroom there are three programs that are actually free.
Erik
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Hi Edmund,
Thanks for being helpfull. I considered looking into Argyll, but the postings by TorbenHR made me realize that it is a bit more complex than I would expect: http://www.luminous-landscape.com/forum/index.php?topic=82891.msg671193#msg671193
Also, I am quite happy with LR. I tried Capture 1 because it is strongly suggested that is the best program for Phase backs, but I don't see the advantages. I spent some time on it (tens of hours) and the more I use the less I like it. So I guess it was a bad investment, not the first one and not the last one.
Best regards
Erik
Erik,
Three names at random for programs generating camera profiles are i1Profiler, Basiccolor Input, and the pervasive and free Argyll.
Iliah has a simple wrapper for Argyll called MakeInputICC. (http://photofeedback.blogspot.fr/2013/07/iliah-borgs-makeinputicc-camera.html)
However it must be said that the practicalities of camera profiling are really difficult; It may take considerable effort to get useful results. In "normal user" hands, the software will resolve difficulties for a given setup and lighting conditions, but rarely yield a good general purpose profile.
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I like the back. It delivers on sharpness and resolution but it fails to deliver on shadow noise. The shadow noise issue is not to bad, it is just below the threshold that matters, I don't have the confidence to pull shadow detail as on the Sony Alphas.
No other camera/sensors can "pull" as much clean shadow detail as the latest Sony full frame CMOS sensors, in the Alphas and the Nikons. Canon's are notoriously bad in this regard. The more you underexpose the image and "lift" exposure the great the difference but there is always a difference.
I can also mention that Chris Barrett posted some sample images using IQ260 compared to his new Sony A7r. As expected the IQ260 was much sharper than the Sony, even on a pr pixel basis, but the image was excessively noisy. True Chris Barrett was using ISO 100 (instead of ISO 50) but that also applied to the Sony (which also has ISO 50 as minimum). The IQ260 image was underexposed, but Chris said that more exposure caused washed out highlights. I downloaded those raw files, and quite clearly the Sony image had more shadow detail. More importantly, normal detail was noisy on the IQ260.
Same comment as above but also, remember the digital backs are CCD not CMOS so they work differently and you start loosing a lot of image quality, specially in the shadows, when you raise iso from the base setting. Some backs have special modes, like the 140iso long exposure mode in the IQ260 and the sensor + mode but generally, if you stray from base iso you are not going to get the best out of the sensor. It gets ugly quick, with the CMOS cameras it is much more gradual. It is what it is. Would I love that to be different? Absolutely.
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Anyway, as OP, I welcome comments from anyone who actually uses my profile within C1.
Please understand that it is an edited profile with a specific look, not a "neutral" one.
Edmund
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Most real world users move a bit back 'n forth to get rid of moire, not do test after test with the specific intention of causing moire and then looking at it 100% for hours.
My old D70s was moire city for most of the time and I used it to death. Like literally, till the camera died on me. I really don't think your P45 is any worse, unless you're obsessed with finding artifacts than making pictures.
Regarding the UI, yeah, C1 is an acquired taste, but the additional detail it resolves plus the color output makes it well worth the pain for me. Once I got the hang of it (Which was only a couple of months ago), I haven't opened LR even once.
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Anyway, as OP, I welcome comments from anyone who actually uses my profile within C1.
Please understand that it is an edited profile with a specific look, not a "neutral" one.
Edmund
Did you make profiles for more of the Phase One backs?
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Did you make profiles for more of the Phase One backs?
Maybe.
And why would you ask :)
Edmund
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Hi,
If you refer to the aliasing article, it was intended to explain aliasing. I used a target designed for lenses, because that target would show the behaviour. This behaviour is not distance specific, you get the stuff so long the lens out resolves the sensor. What I mostly see is not moiré but colour aliasing.
I essentially never shoot in a studio as I am a landscape photographer. In studio shots I presume that you can have a short feedback loop, but in nature less so.
Sample below is a particularly bad case.
Best regards
Erik
Most real world users move a bit back 'n forth to get rid of moire, not do test after test with the specific intention of causing moire and then looking at it 100% for hours.
My old D70s was moire city for most of the time and I used it to death. Like literally, till the camera died on me. I really don't think your P45 is any worse, unless you're obsessed with finding artifacts than making pictures.
Regarding the UI, yeah, C1 is an acquired taste, but the additional detail it resolves plus the color output makes it well worth the pain for me. Once I got the hang of it (Which was only a couple of months ago), I haven't opened LR even once.
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Hi Edmund,
Sorry for the rant. I tried your profile on that shot of myself, and also on another shot of a lady sitting beside me and I was still not happy. Than I moved onto a sculpture in a mediaeval church.
The enclosed screen dumps shows Phase One P45+ outdoor daylight on left and your profile on the right.
Best regards
Erik
Anyway, as OP, I welcome comments from anyone who actually uses my profile within C1.
Please understand that it is an edited profile with a specific look, not a "neutral" one.
Edmund
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Hi Ken,
Thanks for making those things clear. What surprised me in the Chris Barrett shot was that I saw less benefit from the large sensor area regarding noise than I would expected.
The sharpness is there, no questions. It is somewhat similar to what I see on my equipment (39 MP 120 vs 24MP 135).
Best regards
Erik
No other camera/sensors can "pull" as much clean shadow detail as the latest Sony full frame CMOS sensors, in the Alphas and the Nikons. Canon's are notoriously bad in this regard. The more you underexpose the image and "lift" exposure the great the difference but there is always a difference.
Same comment as above but also, remember the digital backs are CCD not CMOS so they work differently and you start loosing a lot of image quality, specially in the shadows, when you raise iso from the base setting. Some backs have special modes, like the 140iso long exposure mode in the IQ260 and the sensor + mode but generally, if you stray from base iso you are not going to get the best out of the sensor. It gets ugly quick, with the CMOS cameras it is much more gradual. It is what it is. Would I love that to be different? Absolutely.
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Hi Edmund,
Thanks for your explanation and thanks for taking time. With regard to Lightroom, for me it is smooth workflow solution. I don't really convert images, I use the raw images. My preferred format is DNG. I never process an image for colour in Photoshop.
I think Lightroom is a bit different since Eric Chan came aboard. I like a lot of features in the new processing pipelines (2010 and 2012), I actually regarding LR to be tone mapping capable a feature I use all the time.
I guess that being a long time LR user (since 2006) I am sort of tuned to Adobe colour rendition.
That said, for the images I posted I had most negative 'votes' for the one processed in C1. The positive votes were pretty split on the LR images. Some are oversaturated, but it can probably be compensated. I wanted to show the results at defaults.
Best regards
Erik
Hi Erik,
You are a Phase One customer and perfectly entitled to publish your opinions. Many of which I agree with, actually.
When it comes to calibration, Phase One use the ICC format, and Adobe used a novel description, DCP files are the DNG profiles, I believe. As an independent member of the ICC I have appreciated the wide array of tools available for a long time for the ICC format, especially since Kodak who invented the Bayer array and much of the technology also pioneered all these matrix-shaper models, and created the first tools. All the tools necessary for editing DNG profiles are not really available outside Adobe, so I would need to create them before I could work as well with their software. I have had various discussions at various times with people at Adobe, including a pretty noisy 15 minutes or so with Thomas Knoll, and the upshot I guess is that they think everyone else is an idiot, and I think they're pretty smart but their results are not as good as they should be, although they are steadily improving. One reason for such smart people arriving at suboptimal results initially is ALLEGEDLY that quite hypothetically quite a few large corporations in the camera industry with well-founded expertise may have been pretty upset with them, and therefore they might have received less help than one would expect from some of the people who make cameras and know them best.
Phase One has the advantage of knowing *their own* cameras really well, and being able to optimize their software and their cameras to work together. I consider C1 to be VERY good in conversion quality, and in many ways superior to Lightroom. The C1 profiles for their own backs are probably exactly what they want them to be; they are not snobbish and know perfectly well that this is open to interpretation. Some of their profiles for third party cameras could be substantially improved. Years ago they asked me to do a bunch of 3d party camera profiles for them, because they had seen my work, and they knew I had industry access and backing. I asked them to sell me a camera at dealer cost (I liked the product), and hold me legally harmless if there were any issues with the profiles and third parties, as I cannot afford legal costs. They refused *both* these requests, and so I never worked with them on this: Request 2 was the deal-breaker. I have since owned a Phase back and it was in many ways a good product, and in some ways problematic, and Phase was neither more nor less difficult to deal with as a customer than any other camera company.
Edmund
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Hi Edmund,
Would it be used with 'film curve' or 'linear response'?
A quick comment on this since I've recently worked with this -- you should not use a capture one ICC profile with a radically different curve than it was designed for. The various contrasty curves are close enough to the default film curve, but the linear curve is quite far off which can lead to distortions of the color, in the tests I've made you often get a bit greenish cast of darker skin tones.
The reason for this is that LUT-based profiles have different color corrections depending on brightness. Eg a bright blue may get a different hue/saturation adjustment than a dark blue. The contrasty curves brightens the image compared to the linear curve. As the ICC profile is applied *after* the curve is applied this means that you'll get different color adjustments depending on the curve.
If we look at DNG and DCP many profiles there are "2.5D" ie they have only hue and saturation correction which is the same regardless of brightness. This is nice because they get brightness-independent. However to get the best corrections one need to be able to have different corrections depending on color brightness and DCP supports this to with full 3D profiles. DCP profiles is however applied before the tone curve which may seem good (as it would be "curve-independent"), but it should not not make any real difference in practice as you always need to have some sort of curve target you calibrate with, and I assume Adobe's profiles are designed for their default curves. Adobe also applies an S-type of contrast curve which causes more color shifts than the gamma-like curve Capture One generally uses. I should say though that I haven't investigated color shifts in Adobe's DCPs in relation to the curve as much as I've done with Capture One's ICC profiles, but I would expect that you'd have same type of performance issues with Adobe's profiles if you change curve to a linear curve (I don't remember now if it's even possible to assign a linear curve in Lightroom though).
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The linear curve in Capture One was designed to be used for reproduction, where the end user will often create their own input profiles. Note that it is intended for use during the capture stage (typically tethered) and the lights should be adjusted accordingly. If one tries to use in in post the result will be under exposed and the tones will be "squeezed"
Yair
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I'd like to remind people that they are free to download my old profile (https://dl.dropboxusercontent.com/u/93354707/P30%2BDaylitePortraMedSat.icc) and make up their own minds.
Think of it like trying out a new film, except in this case there is no need to go out and shoot.
I recommend the standard film-like C1 curve, but of course anyone is free to experiment.
Edmund
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I used to, on occasion, shoot heavily lit fashion tethered to C1, using the linear curve. I found it easier to create contrast with light. This was mainly shooting tests for models and testing lighting set ups. The C1 Film standard could often result is crushed blacks and blown highlights if you light a set using a meter only.
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Dear Erik,
> Please recommend a calibration software, that generates ICC profiles for C1 from a calibration card
Can you upload a couple of your shots of calibration targets, raw?
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Hi,
But I am on travel, back on thursday.
Best regards
Erik
Dear Erik,
> Please recommend a calibration software, that generates ICC profiles for C1 from a calibration card
Can you upload a couple of your shots of calibration targets, raw?
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Hi,
Here they are: http://echophoto.dnsalias.net/ekr//Articles/FakeProfiles/CalibShots/
The ColorChecker shot is what I use for all my profiles. On the Sony I am quite happy with the built in profiles, so I did not mess around with making my own.
Best regards
Erik
Dear Erik,
> Please recommend a calibration software, that generates ICC profiles for C1 from a calibration card
Can you upload a couple of your shots of calibration targets, raw?
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Dear Erik,
I'm afraid the shot is not quite good enough for profiling, the values on the black frame around ColorChecker Passport vary up to 12%, and the white balance is not uniform enough too. I placed 66x66 pixels samples on the frame like this, numbered clockwise, first one is upper left corner.
(http://cl.ly/image/0c1Z1e1g2S3g/20130802-CF043649-20131218-164040-RawDigger-ScreenShot.png)
Exported values to csv, original csv attached. Opened the file in Excel and for each colour channel calculated sample average divided by minimum average, Excel spreadsheet attached.
On a side note, I would try to clean the target or, even better, use a ColorChecker SG as it in my experience always result in more realistic and usable profiles compared to using just ColorChecker.
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I do of course regret that when asked to contribute to the specs for this target I didn't more vocally insist on a uniformity check. Mea culpa. Maybe we could debate on features we could request for a future version? My feeling is that the smaller the total sample area the better, as this reduces light falloff effects across the active area, but some tricks might improve software flare reduction too.
Edmund
Dear Erik,
I'm afraid the shot is not quite good enough for profiling, the values on the black frame around ColorChecker Passport vary up to 12%, and the white balance is not uniform enough too. I placed 66x66 pixels samples on the frame like this, numbered clockwise, first one is upper left corner.
(http://cl.ly/image/0c1Z1e1g2S3g/20130802-CF043649-20131218-164040-RawDigger-ScreenShot.png)
Exported values to csv, original csv attached. Opened the file in Excel and for each colour channel calculated sample average divided by minimum average, Excel spreadsheet attached.
On a side note, I would try to clean the target or, even better, use a ColorChecker SG as it in my experience always result in more realistic and usable profiles compared to using just ColorChecker.
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Yes, flare is a problem. For uniformity, maybe an N8 grey border? The cross in the middle is unnecessary IMHO, as in my experience it is better to shoot targets out of focus.
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Yes, flare is a problem. For uniformity, maybe an N8 grey border? The cross in the middle is unnecessary IMHO, as in my experience it is better to shoot targets out of focus.
The idea was to provide an aim point, and an element of repeatability. Otherwise people tend to choose one of the fields but not always the same one as an aim point. What was the name of that book? Camera Profiling for Dummies?
Edmund
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I see. What I would suggest is a neutral grey cover sheet for flat field and an overlay for any focusing needs.
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I see. What I would suggest is a neutral grey cover sheet for flat field and an overlay for any focusing needs.
What features would you like to see adjacent to the color fields of a chart?
Edmund
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If there is a hard N8 sheet to cover the target, all I want that the plastic frame has no specular reflections.
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I'm doing a different design :)
What sort of fields would you like on the target?
Please remember that when doing "Profiling for Dummies" you basically get one test shot. Which should be sharp because in a repro cycle it is a production exposure.
Edmund
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Dear Iliah.
Learning all the time ;-)
I would expect the target to be evenly illuminated, as all corners are approximately equal distance from the sun, but I was concerned about contamination from surrounding light. This time I had my target on metal table.
Can we use studio flash for D50 or D60 reference or we do need real sunlight? Studio flash is simpler, but I have not really found a description of spectral distribution of flash light, so I don't know how well it approximates an D-series illuminant.
Anyway, one nice thing with raw is you can always change a profile.
Best regards
Erik
Dear Erik,
I'm afraid the shot is not quite good enough for profiling, the values on the black frame around ColorChecker Passport vary up to 12%, and the white balance is not uniform enough too. I placed 66x66 pixels samples on the frame like this, numbered clockwise, first one is upper left corner.
(http://cl.ly/image/0c1Z1e1g2S3g/20130802-CF043649-20131218-164040-RawDigger-ScreenShot.png)
Exported values to csv, original csv attached. Opened the file in Excel and for each colour channel calculated sample average divided by minimum average, Excel spreadsheet attached.
On a side note, I would try to clean the target or, even better, use a ColorChecker SG as it in my experience always result in more realistic and usable profiles compared to using just ColorChecker.
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This time I had my target on metal table.
what about a lot of light being reflected from metal surface back into your lens ?
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Can we use studio flash for D50 or D60 reference or we do need real sunlight?
as far as I remember what he was writing about a simple setup - it was a stabilzed (voltage) halogen floodlight w/ gel(s), reflected off brushed aluminium metal surface on the target (not a direct illumination)
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Iliah is right.
Best regards
Erik
as far as I remember what he was writing about a simple setup - it was a stabilzed (voltage) halogen floodlight w/ gel(s), reflected off brushed aluminium metal surface on the target (not a direct illumination)
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Hi,
I don't think so. The metal area is dark, so it is reflecting away from the lens. But I think it may reflect skylight on the target. On the other hand, the grey patches had quite normal colour temperature, so I assumed that would not be a problem.
Lot of food for thought…
Best regards
Erik
what about a lot of light being reflected from metal surface back into your lens ?
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as far as I remember what he was writing about a simple setup - it was a stabilzed (voltage) halogen floodlight w/ gel(s), reflected off brushed aluminium metal surface on the target (not a direct illumination)
I guess you mean this one:(http://cl.ly/3l0Q2Q0t2m1738340n0C/Screen%20shot%202012-03-17%20at%209.54.49%20PM.png)
Well, a uniform and very flat grey cover sheet helps to make light setup less demanding through the application of flat field, but the point re halogen flood lights with CTB filters still stands.
Flat field is especially important these days because sensors add digital vignetting (and sometimes it is non-neutral, too; meaning the colour is changing) on top of lens vignetting. Playing with lights to compensate for digital vignetting is a waste.
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I guess you mean this one:
not this one - this one is more complex (2 lights + 2 reflecting surfaces to illuminate the target indirectly).
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Hi,
I don't think so. The metal area is dark
you still can see specular highlights on it in your shots means it is still reflecting something right in your lens - what if that adds to microghosting and flare...
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you still can see specular highlights on it in your shots means it is still reflecting something right in your lens - what if that adds to microghosting and flare...
Right. Flare and glare are two bad guys.