White or Black Color base?

[mcddeb]

In researching making corrections in Photoshop, I have read on other forums and in tutorials that Canon uses a white color base and Nikon uses black as a color base. What does the Sony A700 use? This is important as it is the basis of what you need to know to do adjustments in PS accurately. I have also read this would affect what color the chosen camera brand likes to get the best white balance, some do better using a white card as opposed to the universal 18% gray card. Thoughts, anyone know?

After posting this, it occurred to me since Sony makes the sensors for Nikon, it's probably black. Anyone know for sure?

[Javelin]

I don't know about colour base but it might have to do with how each camera brand derives it's colours. a grey card some consider important to set your exposure and white ballance is 18% greay which means it's halfway between black and white. But a lot of people think it should be 12% grey for digital cameras instead. maybe what your asking is if a given camera will define it's whites based on more towards black than white on the greay scale? for example maybe Canon likes 18% grey and Nikon likes 12% grey more which would seem to have more to do with how each manufacturere calibrates it meters.

I found this site which explains the arguments pretty well and also gives you a tip to decide how to set your given camera up. he suggessts shooting a grey card with bracketing and picking the exposure you like and use an ev adjustment to get that every time you use the grey card.

http://www.bythom.com/graycards.htm" onclick="window.open(this.href);return false;

[mcddeb]

I think that is what I was trying to say. I too have read that about the 12% gray card and haven't seen it mentioned in anything else I have read. As I am studying ways to become a better photographer, I was thinking it would be a waste of effort to keep metering off a gray card if my camera had a native white base preference. Thanks for the link, I will check it out.

Debra

I read the link, thanks so much for referring it. I was beginning to think I had made it up in my head about the 12% thing. I wonder how Will Crockett's method of metering off the palm of your hand in the field if you don't have a gray card with you mixes with this? I've been spending a lot of time lately reading tutorials and books on exposure and Photoshop techniques, I have to wonder - are we over thinking the process somewhat? I have seen critiques of what I thought were great photographs that just slaughtered the photo in terms of color, composition, etc.

[David Kilpatrick]

The 18% grey card was based by Kodak on the old ASA rating of films and the calibration of meters prior to a date (which I can not find) in the 1950s when the ASA and DIN ratings for films were revised. Kodachrome used to be rated at DIN/ASA 12°/12 but was 'uprated' without any change to the emulsion itself, to 15°/25 - at the same time, metering off the 18° grey card began to produce underexposure relative to the average European scene on which the standard was first based.

Geoffrey Crawley, around 1978, proposed a revision of the standard to 12% grey based on the observation that most modern TTL meters were calibrated to 12%, not 18%. The discussion about 12 versus 18 dates from Geffrey Crawley's original research, but Kodak would not change the standard of their grey card. In fact the grey card remained unchanged and was never updated to cope with colour photography. It has a very unequal spectral response with a peak at the red end of the spectrum, meaning it's not really grey but magenta-ish.

In 1996 (?) Douglas West was discussing this problem with me, as he wanted to make a write-wipe vinyl grey card similar to the Agfa Color Target. We had just had some ring binders made with vinyl covering card, so we put him in touch with the maker, suggesting a folding white-grey card. Folding enables contrast judgement (a method pioneered by US photographers such as Monte Zucker, and taught in the UK by Ian Gee, whose Guild of Wedding Photographers newsletter we were producing at the time). You hold the card 90 degree folded and compare shadow and highlight values. White enables white balance, grey for exposure. Douglas then sourced a dozen and more types of vinyl. We requested vinyls made using mineral fillers, not dyes, to produce the grey colour.

Shirley had just obtained her MSc in Colour Science, we had the measurment equipment to hand, so she tested all the vinyls and came up with one which showed an equi-energy spectrum (that is, a straight line from far blue to far red). It was fairly close to 18%, the error was towards the 12% side not the other way. We recommended this material and Douglas went into production. The card is A4 folding to A5, to fit in camera bags, it can be written on with a wipe-off pen or chinagraph, and it will give accurate WB readings under any illumination (which the Kodak card does not). We were working for Paterson Photographic at the time, and suggested they bought the product as a branded line, which they did. I believe Douglas approached Kodak, but since the research was ours, not theirs, they declined - Kodak has the strangest hangup about in-house science versus anyone else!

Douglas just issued a new run of the card, over a decade later, and it remains about the best everyday grey/white card you can have. We never made a penny from this - it was done in the interests of creating better grey card, with the help of a one-man band 'manufacturer' who shared our ideas. We do get this credit: "Our innovative design has been developed from the groundbreaking concepts of Icon Publications Ltd."

See: http://www.photo-software.com/greycard. ... 3godGk8hCw" onclick="window.open(this.href);return false;

David

[Javelin]

Thats a great link .. the only cards I could find were simple kodak ones that the person selling says nobody really uses. I am shooting pictures in ajn arena where depending on which side you on has diferent lighting and it just destroys any atempts at WB. can get a decent sertting off of a white surface but it's far fom perfect. I want a grey card to get it right before I even start... the white surface gives me 3800K or something and it should be just a tiny bit warmer to be right.

[mcddeb]

Thanks David, fascinating to read. It's amazing how most people don't think what the science behind taking a photograph entails. I have to admit I never really thought much about it myself until I got into photography this past couple of years and really the past few months of wanting to do more than use modes and click a button. I will most certainly get one of those targets.

Thanks for your patient and clear teaching.

Debra

[01af]

... Canon uses a white color base and Nikon uses black as a color base.

That's pure nonsense.

-- Olaf

[mcddeb]

That is a rather cryptic reply. I confess I am not a scientist or technically advanced person. It is something I have read from a couple of different sources. The last article I read before posting my question said the white color base is responsible for the "ethereal skin effects" you get from Cannon and the black base explains the vivid colors of Nikon. I honestly don't know if it is correct or not. Are you a scientist or camera technician? Why do you say it is nonsense? I don't care if it is or isn't, I was curious if anyone else had heard of it or not. And if it indeed had anything to do with the differences in the images you get from either camera, especially in regard to the images I get from my Sony. And if anyone knew, it would certainly be David or the other knowledgeable people on this forum who so generously share knowledge without making a person feel stupid.

D

[Alain]

...
In 1996 (?) Douglas West was discussing this problem with me, as he wanted to make a write-wipe vinyl grey card similar to the Agfa Color Target. We had just had some ring binders made with vinyl covering card, so we put him in touch with the maker, suggesting a folding white-grey card. Folding enables contrast judgement (a method pioneered by US photographers such as Monte Zucker, and taught in the UK by Ian Gee, whose Guild of Wedding Photographers newsletter we were producing at the time). You hold the card 90 degree folded and compare shadow and highlight values. White enables white balance, grey for exposure. Douglas then sourced a dozen and more types of vinyl. We requested vinyls made using mineral fillers, not dyes, to produce the grey colour.

Shirley had just obtained her MSc in Colour Science, we had the measurment equipment to hand, so she tested all the vinyls and came up with one which showed an equi-energy spectrum (that is, a straight line from far blue to far red). It was fairly close to 18%, the error was towards the 12% side not the other way. We recommended this material and Douglas went into production. The card is A4 folding to A5, to fit in camera bags, it can be written on with a wipe-off pen or chinagraph, and it will give accurate WB readings under any illumination (which the Kodak card does not). We were working for Paterson Photographic at the time, and suggested they bought the product as a branded line, which they did. I believe Douglas approached Kodak, but since the research was ours, not theirs, they declined - Kodak has the strangest hangup about in-house science versus anyone else!

Douglas just issued a new run of the card, over a decade later, and it remains about the best everyday grey/white card you can have. We never made a penny from this - it was done in the interests of creating better grey card, with the help of a one-man band 'manufacturer' who shared our ideas. We do get this credit: "Our innovative design has been developed from the groundbreaking concepts of Icon Publications Ltd."

See: http://www.photo-software.com/greycard. ... 3godGk8hCw" onclick="window.open(this.href);return false;

David

David

Nice, are they colored material (as I seem to read) or "painted"? I suppose that the white part is also as good as the grey part.
Are the mark II card the same material aka do they have the same spectral response?

"Folding enables contrast judgement" : Can you give some more information, the sentence above isn't clear to me.

Alain

[David Kilpatrick]

I'll try to find Ian Gee's original article on using folded cards for contrast assessment. I am pretty sure the new Douglas Grey card is a different vinyl formulation, but he has tested it the same way to get one without any peaks or troughs in the response. Both the white and black sides are non-brightened, self-coloured vinyl using filler to achieve the grey colour, and very light-permanent. They are not painted.

David

[01af]

"... Canon uses a white color base and Nikon uses black as a color base."

That's pure nonsense.

That is a rather cryptic reply.

Cryptic ...huh!? Which part of "that's pure nonsense" didn't you understand?

It is something I have read from a couple of different sources.

Sure. I did understand this nonsense isn't yours but coming from some obscure sources.

The last article I read before posting my question said the white color base is responsible for the "ethereal skin effects" you get from Canon and the black base explains the vivid colors of Nikon.

And that's nonsense---as simple as that.

I honestly don't know if it is correct or not.

... so you're asking. That's fine. And the answer is: it's not correct.

Why do you say it is nonsense?

Because it is.

The only thing I can think of that's remotely connected to "black colour base" or "white colour base" is additive and subtractive colour models. Primary RGB colours add up to white; primary CMYK (or CMY) colours add up to black. However this has nothing to do with digital cameras and their allegedly different colour bases. All digital cameras naturally are using the RGB colour model ... so do all colour monitors and TV sets. And there is no such thing as a "colour base" which might be either "black" or "white."

I don't care if it is or isn't ...

You don't!? Then why are you asking anyway?

And if anyone knew, it would certainly be David or the other knowledgeable people on this forum who so generously share knowledge without making a person feel stupid.

I know, and I told you. Did you notice that no-one (except me) here responded to that "black or white colour base" thing yet? Wanna know why? Because it's nonsense, that's why. Sorry if being told that something you've read is nonsense makes you feel stupid.

-- Olaf

[mcddeb]

Now, now 01af, no need to act like an oaf. I meant I have no vested interest as in it wasn't my theory of the white/black color base, so I didn't care if someone disproves it or not. I wanted to know for the sake of learning how to best adjust my camera. I understood "pure nonsense" completely, but you didn't base it on any facts which is why I said "cryptic reply".

As for making me feel stupid, you didn't, so no need to apologize. It appears you have a need to feel superior to others which is why you write in such a negative, condescending manner. Too bad, because indeed you do sound knowledgeable, but when you write in such a rude manner, I hazard a guess no one will want to read your comments and will not be able to benefit from your knowledge. From what I have read from you so far, I would say you have a long way to go before I value your opinion or comments as much as I value David's and others in this forum.

If you find my commentary offensive, stupid, ignorant or whatever adjective you would insert here, I truly invite you to ignore me completely and move on to another topic.

D

[01af]

If you find my commentary offensive, stupid, ignorant or whatever ...

I didn't take any offense, and I don't think you're stupid or ignorant. At worst, one could say you're uninformed ... or rather, in this particular case, misinformed. We all are uninformed about most things and well-informed about a few things. And that's what a special-interest forum like this is about: it helps people turning from uninformed into informed state. So please note that I never said you were stupid---it's you who used that word.

... I truly invite you to ignore me completely and move on to another topic.

Thank you very much. Maybe I should accept that invitation. But before I do so, please note that I am the only person who actually responded to your primary inquiry ... even if you didn't like the answer. All the others immediately digressed from the "colour base" topic to the grey card topic (which you did mention in your original post but wasn't your primary point). That's because a grey card discussion makes sense, much unlike a "black or white colour base" discussion.

Maybe you want to point us to those "sources" where this absurd "black or white colour base" thing is coming from ... if they happen to be on the Internet.

-- Olaf

[mcddeb]

Thank you and you are correct. You are the only one that addressed the color base issue. Perhaps it relates to how the sensors reads the card, but that was not spelled out specifically, so I still do not know for sure other than your assertion that it is nonsense. The internet post I was referring to was on another forum called I love photography and was posted by Andrea Joki. I have read it somewhere else, but for the life of me can't remember where.

Indeed, you didn't call me stupid, sometimes the way a person writes things seems to infer their thoughts as opposed to what they express. And you are correct at any given moment, I or anyone else for that matter, am uninformed or misinformed which is why I posted the question to begin with.

I like you much better when you play nice.

Debra

[David Kilpatrick]

I didn't reply to the black or white colour base since it has no meaning, and therefore no comment can be made about it. It's like asking whether a car use kilometre petrol or miles petrol.

Both cameras take raw files. To create a WB JPEG (a raw file has no WB, only a tag to help post-processing) it is impossible to work from the blackpoint as that has no colour content, but the blackpoint will have an effect on the channels. Nikon clips the blackpoint - it's a feature of all their current raw conversions. This should not have any effect on either white or grey card balance readings, but it might lead to the confusing terminology used.

Many point and shoot cameras, because they can adjust the whitepoint live using the image from the sensor (Live View), do a better job making the brightest highlights white than some DSLRs do. Nikon also has some cameras with an external WB sensor, and so does Olympus. Both of these over-ride any calculations made from the raw image, or work alongside these calculations. Since not all Nikon DSLRs feature the external WB sensor, they clearly do not have only one way of handling WB.

If you want a really accurate WB, try the Expodisc (or a Pringles tin lid) and take the reading from the incident light, not from the subject. Doing this preserves subtle colours introduces by nearby surfaces into the shadows, while cleaning up directly lit areas perfectly. It also deals well with situations where only reflected light is reaching the subject.

I realised I have never put many of my pre-June 2006 magazine articles on to Photoclubalpha, so I found the files for a test of the ExpoDisc from back then - on a KM 5D, which is you will read has one of the best designed custom WB systems ever put into a DSLR (the A100 shares it):

http://www.photoclubalpha.com/2009/01/0 ... -dynax-5d/" onclick="window.open(this.href);return false;

David