Grey card white balance and camera profiles for flower close-ups

[GardenersHelper]

In this thread Andrew (@lightshipman) posted 4 images of an orchid and the issue of white balance was raised by a couple of us. I mentioned the possible use of a grey card to help adjust white balance. I have found grey card adjustments so useful that I thought it might be interesting to provide an example. I have also been using camera profiles recently, which I have also found useful, albeit more subtle in their effects, so I thought I would add that into the mix.


Gray card adjustments

You can use grey card adjustments for both RAW and JPEG images. You have to use post processing software that knows how to handle white balance adjustments, which I think is the case with most image editors.

To make grey card adjustments to an image you first need to capture a "white balance reference image" of something neutral coloured, typically a white or grey card (not any old white looking or grey looking card, but one that has been prepared specifically for photographic purposes to be absolutely neutral). While out taking photos you capture an image of the card every now and then, like this.


0601 7 IMG_5581 Shooting a white balance reference shot by gardenersassistant, on Flickr

I use a piece of white and a piece of grey card. White is meant to be better for white balance adjustment, but is easy to over-expose, so if the white area of the reference images does get over-exposed I use the grey area instead. Grey seems to work fine as far as I can tell.

When you come to post process your images you use the eye dropper tool on a white balance reference image to set that image's white balance. You can then copy that white balance to other images.

The following illustration shows the same shot, captured with a Canon 70D. At the top left is what the image looked like when processed using the "As shot" white balance. At the top right is what it looked like after using a grey card adjustment.


0601 1 70D White balance x camera profile by gardenersassistant, on Flickr

Cameras often have trouble with colours in the blue/purple range. In this case the grey card adjusted image is much more realistic, and I find that generally to be the case.



Camera profile adjustments

Different cameras capture colours differently, and even two cameras of the same model can differ a bit apparently, and different makes and models can differ a lot. To counteract this and get more of a "standard" or (hopefully) "realistic" rendering of colours you can use camera profiles.

Unlike with grey card adjustments, camera profiles only work with RAW images. You have to use post processing software that knows how to handle camera profiles. This is less common that with white balance adjustments. Photoshop, Elements and Lightroom can use camera profiles. I don't know about other software.

As with grey card adjustments, you capture reference shots. In this case the shots are of a multi-coloured target, like this.


0601 8 P1490299 Shooting a camera profile reference shot by gardenersassistant, on Flickr

You then create a "camera profile" for the camera that captured the reference shot. I do this using Adobe DNG Converter, which converts a RAW image into a DNG image, and then DNG Profile Editor to create the camera profile. (DNG converter and DNG profile editor are both free, and the conversion to DNG and the preparation of the camera profile are both quick and easy.)

If your post processing software knows about camera profiles you can tell it to use the appropriate camera profile instead of the general purpose profile that it normally uses. The bottom two images in the composite image above illustrate the effect of using a camera profile. At the size shown above the effect looks rather slight, if you can see it at all. However, if you compare larger versions of the image the differences are much more clearly visible. Here are larger versions of the image, with 1100 pixel high versions available at Flickr. Both of these used a grey card adjustment. The first uses Lightroom's general purpose "Adobe standard" profile. The second uses a camera profile prepared for the 70D that captured the shot.

If you can download the images and flick between them so that one replaces the other without you moving your eyes the differences will be much easier to see than if you try to compare them by moving your eyes from one to the other on this page or in some other software. I use Faststone image viewer to flick between images - it lets me switch instantly back and forth between images using the arrow keys so I can keep my eyes fixed on a particular part of the image as I flick back and forth to compare them.

Adobe Standard profile

0601 3 IMG_5578 Grey card WB, Adobe Standard profile 1100h by gardenersassistant, on Flickr

70D camera profile

0601 4 IMG_5578 Grey card WB, 70D camera profile 1100h by gardenersassistant, on Flickr

For the comparisons I have done, I have generally found the versions using camera profiles to be more pleasing to my eye, and more realistic. For the most part (but not always) they seem to have more "depth"/clarity or some such, to be more subtle/less garish, and to have more realistic colour rendition. I routinely use camera profiles these days.

There is an issue as to whether you need to make one or more camera profiles every time you go out shooting, or whether you just need one profile for a camera, or perhaps a few for different conditions. It seems to me that for the most part different profiles for a particular camera produce fairly similar results, the main possible exceptions being (if it is sunny) very early in the morning, shortly after dawn, and late in the afternoon, shortly before sunset. It also doesn't seem to matter much whether reference shots are captured in the sun or in shade.


Grey card and camera profile adjustments for different cameras

The above examples relate to a Canon 70D dSLR. Both techniques work for other cameras. Grey card adjustments work for any camera, and camera profiles can be used for any camera that can capture RAW images (as long as those images can be converted to DNG images).

Here is a shot of the same flower, on the same day, captured a few minutes before the 70D version, using an FZ200 bridge camera. (Unfortunately this shot used a very small aperture and the 70D version used a much larger aperture, so the dof is very different in the two versions. They were not captured as test/comparison shots, but are the most suitable and similar images I can find for this comparison.)


0601 2 FZ200 White balance x camera profile by gardenersassistant, on Flickr


Adobe Standard profile

0601 5 P1490307 Grey card WB, Adobe Standard profile 1100h by gardenersassistant, on Flickr

FZ200 camera profile

0601 6 P1490307 Grey card WB, FZ200 camera profile 1100h by gardenersassistant, on Flickr

It is possible that these techniques are even more useful for my FZ200 than my 70D because it seems to me that the auto white balance on the FZ200, and the unadjusted colour rendition on the FZ200, are not as good as on the 70D.

 

[lightshipman]

Nick,
This is another very interesting article, and written in a very understandable format, I will digest this over the weekend and try to do some experimenting using grey and white cards.

 

[TimmyG]

Excellent Nick! I don't use a grey card (I don't own one) but I really should. I usually shoot with just the light from the flash, so tend to stick to the flash balance, but always end up adjusting slightly in post. This is only ever to my own tastes (and on my own monitor) so not very accurate at all! Add to that the fact any diffusion I am experimenting with might throw the colour balance way off! I really should be more methodical in my approach.

 

[orionmystery]

Great tip! Might work for non-skittish bugs too!

 

[GardenersHelper]

Excellent Nick! I don't use a grey card (I don't own one) but I really should. I usually shoot with just the light from the flash, so tend to stick to the flash balance, but always end up adjusting slightly in post. This is only ever to my own tastes (and on my own monitor) so not very accurate at all! Add to that the fact any diffusion I am experimenting with might throw the colour balance way off! I really should be more methodical in my approach.

My card is white on one side and grey on the other. I have cut two strips from it and have them in a little wallet thingy and pull them out a bit when I want to use them. They get a bit beaten up over time so I just cut new strips to use.


P1490348 LRS1 by gardenersassistant, on Flickr

I sometimes alter the white balance during post processing even when using a grey card adjustment and camera profile. It's still a judgement call, and I'm not so much interested in accuracy (which is a bit of a difficult concept I think when you dig into it) as what looks good to my eye, on my monitor, in whatever the ambient light happens to be when I'm doing the processing! And in any case I don't take a grey card reading for every shot. In fact, I often end up with only one or two for a whole session. I really should do more, as the white balance can vary considerably from shot to shot, for example depending on the position of the subject in relation to foliage and the colour of that foliage, and when moving between sun and shade - and of course if the sun is going in and out behind clouds, or you are working under foliage that is moving in the breeze and continually changing the ambient lighting, that can make it impractical to get an "exact" grey card reading for a particular shot. So this these are "helper" techniques, not a rigid "make it correct" type of thing.

With your very small subjects I imagine flash is the primary light source, so using a "flash" white balance makes sense (subject of course to diffuser colour cast issues). But for many of my shots when I use flash, the light is a mixture of ambient and flash light, and a mixture which varies between different parts of the image (the more distant, the greater then ambient contribution, but also for the subject especially if I have the flash turned right down so as to be providing fill, so different parts of the subject may have different white balances. These combinations are never going to be "right", but I have recently been using grey card and camera profiles to help with flash shots too.

 

[Steve Smith]

I understand that a grey card is traditionally used for exposure measurements, but why use it for white balance? To me, it makes more sense to white balance with a white card as it's much easier to produce a neutral white than a neutral grey.

(I appreciate that you mentioned white or grey in the first post).


Steve.

 

[GardenersHelper]

Great tip! Might work for non-skittish bugs too!

Absolutely. I use the same techniques for bugs, especially when using available light, but also sometimes (see previous post) when using flash.

I now use a camera profile routinely (which, because they don't vary much as the conditions vary, may or may not have been captured during the shoot in question). However, I'm not very methodical about when I do and don't use a grey card even with natural light shots, and even less so when using flash.

I suspect my use of these techniques will settle down when I've been using them a bit longer. It's all still a bit experimental at the moment, and in any case when I am out taking photos I tend to get wrapped up in the capturing (finding, framing, exposing) and forget about capturing reference shots. I am trying to develop better habits so the use of these techniques, especially grey card reference shots, becomes a natural part of the capture process that I don't need to remember to do, but just do as a matter of course.

 

[GardenersHelper]

I understand that a grey card is traditionally used for exposure measurements, but why use it for white balance? To me, it makes more sense to white balance with a white card as it's much easier to produce a neutral white than a neutral grey.

(I appreciate that you mentioned white or grey in the first post).


Steve.

Indeed so. I have got my terminology a bit skewed here I'm afraid. I realised that part way through drafting the top post and was lazy and didn't go back and amend it. I should really refer to "white card" rather than "grey card", or better yet perhaps a "neutral card". Instead I just wrote "White is meant to be better for white balance adjustment, but is easy to over-expose, so if the white area of the reference images does get over-exposed I use the grey area instead. Grey seems to work fine as far as I can tell." I do use the white in preference to the grey, and only use the grey if the white is over-exposed. I could definitely have been clearer about that. Sorry, and thanks for pointing it out.

 

[chris malcolm]

Having trouble with flower colours I decided to photograph a flower, print it, and hold the print beside the flower. Lunch intervened between photographing and print comparison. The result was terrifying!

I later discovered that Morning Glory flowers change colour as the day progresses! I also discovered the problems of fluorescence, metamerism, etc..

Acquiring and using a white balance card HSS helped a lot. It's interesting to see the camera profile differences. I don't understand why simply setting white balance with an accurate reference card doesn't automatically carry any camera profile inaccuracies along with it.

 

[Whippet]

I used one of these yesterday for a product shoot of some Xmas chocolates

Not yet pp'd the set but the ability to set white and black points as well as colour balance looks handy. Should really have got the Colorcheckr reference card as well to set a profile as per the OP to get the colours as accurate as possible...

 

[jockwav]

Just to add - grey cards can be used for more than just metering. You can also use it to do a custom white balance. For custom WB, you don't necessarily need a 'white' object, just a 'neutral' one. A grey card is neutral.

Many programs allow you to just click on an object with a dropper tool and apply that setting to any number of photos. You can also set a custom WB in camera (usually by taking a picture of a suitable target, then setting that as the 'correct' WB).

Just another reason to have a grey card... They're so useful (and relatively cheap as well) that there isn't really any reason not to have one.

 

[GardenersHelper]

Having trouble with flower colours I decided to photograph a flower, print it, and hold the print beside the flower. Lunch intervened between photographing and print comparison. The result was terrifying!

I later discovered that Morning Glory flowers change colour as the day progresses!

I also discovered the problems of fluorescence, metamerism

"metamerism" - had to look that one up. Very interesting indeed. Thanks. More complications for the "what is the real colour" conundrum.

Acquiring and using a white balance card HSS helped a lot.

"HSS"?

It's interesting to see the camera profile differences. I don't understand why simply setting white balance with an accurate reference card doesn't automatically carry any camera profile inaccuracies along with it.

Can't say I understand it either. It's the white balance that has the big effect, but camera profiles do seem to be useful, albeit in a rather more subtle way. To my eye they appear to improve the colour accuracy and also (difficult to pin this down) change the distribution of colours and brightness in some way that seems to improve the clarity/local contrast/"impact" or some such.

There can also be differences using profiles for which the reference images were captured in different conditions, but quite often when I've tried alternative camera profiles the results have been pretty much identical to my eye.

 

[GardenersHelper]

I used one of these yesterday for a product shoot of some Xmas chocolates

Not yet pp'd the set but the ability to set white and black points as well as colour balance looks handy. Should really have got the Colorcheckr reference card as well to set a profile as per the OP to get the colours as accurate as possible...

That's an interesting looking device.

As for the Colorchecker, I think I might have just purchased a (rather less expensive) card if I had known that you don't actually need to use the software that comes with the Colorchecker. Indeed, I prefer the free software and don't use the Colorchecker software. It is quite handy though to have the Colorchecker, with it being relative small and in a robust enclosure.

 

[Whippet]

That's an interesting looking device.

As for the Colorchecker, I think I might have just purchased a (rather less expensive) card if I had known that you don't actually need to use the software that comes with the Colorchecker. Indeed, I prefer the free software and don't use the Colorchecker software. It is quite handy though to have the Colorchecker, with it being relative small and in a robust enclosure.

Sounds like a good idea but any ideas where you can get a cheap but accurate colour reference card? The Datacolor SpyderCheckr 24 which has a LR plugin is £42, stand alone cards I've found seem to be more than that.

 

[GardenersHelper]

Sounds like a good idea but any ideas where you can get a cheap but accurate colour reference card? The Datacolor SpyderCheckr 24 which has a LR plugin is £42, stand alone cards I've found seem to be more than that.

Cheap, £12, this one.

Accurate? Don't know I'm afraid. The user reviews seem ok, but there are only 11 of them on that Amazon uk link, and 24 at Amazon.com, and none of them apparently from an expert who might have compared results with one of the more expensive ones. I didn't find any useful looking reviews elsewhere either I'm afraid.

Note the comments, especially at Amazon.com, about how very small it is. From my point of view, for close-ups using achromats, that would actually be an advantage, but that may not be the case for you of course.

I haven't found the need for a Lightroom plugin. But again of course YMMV.

 

[lightshipman]

Following on from Nicks original description of using a grey card, I did a bit of experimenting today, using a grey card for the first time ever. The following four images are the result, forget focus, I didnt set up my tripod or use manual focus, it was calibrate using grey card and hand held shooting.
No grey card calibration

No grey card calibration
DSC_2971 by andrewwright4, on Flickr

And grey card calibration
DSC_2972 by andrewwright4, on Flickr

A very worthwhile exercise, now I will be carrying a grey card around with me.

 

[GardenersHelper]

I did a bit of experimenting today, using a grey card for the first time ever. The following four images are the result, forget focus, I didnt set up my tripod or use manual focus, it was calibrate using grey card and hand held shooting.

......

A very worthwhile exercise, now I will be carrying a grey card around with me.

(As pointed out above by Steve, my use of the term "Grey card" is a bit misleading when we are talking about white balance, so I'm switching to the term "Neutral card").

I'm glad you are experimenting - that is definitely the way to go. However, I have to admit to being a bit puzzled about exactly what you did here. When I've been thinking about the effect of using a neutral card I've compared the same image, processed once using Auto White Balance and once using the White Balance taken from a Neutral card reference shot. What I see here is seven different images. Can you help me understand this please Andrew.

The other thing I'm puzzled about is why the exposures are so different. The first two "without grey card calibration" images look over-exposed, and the third one looks under-exposed. The exposure looks ok for all four of the "grey card calibration" images. Is this related to how you used the grey card?

 

[lightshipman]

I set up my little table outside, the sky was over cast, with no direct sun, I placed the grey card on the table at the side of the flower and set up the AE lock button, then took the photos, very hit and miss, as when I started the bracketing funtion was on, so I picked the images with 0.0ev. I was really suprised at the difference in the exposure for the flowers, in the close up photo, the petals are 'burnt out' or nearly so, whereas with the corrected shots the colours are so much more accurate.
Somehow the images have got mixed up, each pair is supposed to be a similar shot, one without grey card calibration and one with, post needs editing!!
I imagine the creme de la creme would be to set the grey card directly alongside the subject matter and continue from there, I was being disturbed all the time by phone calls from work so really getting a bit stressed out. Will now carry on experimenting at leisure!!!
Re read my post above, the pictures are all out of sequence, am trying to rectify!!!

 

[GardenersHelper]

I set up my little table outside, the sky was over cast, with no direct sun, I placed the grey card on the table at the side of the flower and set up the AE lock button, then took the photos, very hit and miss, as when I started the bracketing funtion was on, so I picked the images with 0.0ev. I was really suprised at the difference in the exposure for the flowers, in the close up photo, the petals are 'burnt out' or nearly so, whereas with the corrected shots the colours are so much more accurate.
Somehow the images have got mixed up, each pair is supposed to be a similar shot, one without grey card calibration and one with, post needs editing!!
I imagine the creme de la creme would be to set the grey card directly alongside the subject matter and continue from there, I was being disturbed all the time by phone calls from work so really getting a bit stressed out. Will now carry on experimenting at leisure!!!
Re read my post above, the pictures are all out of sequence, am trying to rectify!!!

I'm still puzzled I'm afraid. FWIW I capture shots from time to time with a neutral card in them, but I only use those shots to get the white balance from them. Shots that I process for viewing never have the card in them. So, when I'm shooting a subject I take some shots and then I just hold the card in front of the subject and take another shot - that is the shot I take the white balance from, and apply that white balance to the other shots.

I'm trying to understand your "in the close up photo, the petals are 'burnt out' or nearly so, whereas with the corrected shots the colours are so much more accurate." It seems to me there are two separate issues here, one being whether the exposure is ok and the other being how accurate the colours are. Perhaps I'm just being a bit thick here (wouldn't be the first time )

I wonder though - are you capturing some shots with the card in them, from further away, and then cropping out the card, and comparing that shot to another one taken from closer in that doesn't have the card in it?

 

[lightshipman]

nick,
Im afraid the photos are really mixed up, thay should follow a more logical sequence with firstly a shot taken just by switching the camera on and taking the shot in aperture priority, using the cameras normal auto mode, the next one should be a similar shot but after having calibrated my camera with the grey card on the table at the side of the subject, I then composed the subject with my AE locked, not including thegrey card, and the shot was taken, initially I did one of each close up, and then further away. I was trying to edit the post and switch the photos around, and yes the posted pictures have different exposures, again part of my mix up sorry, they should all be the same exposure, which the images I meant to post have.

 

[lightshipman]

All these photos are same exposure, but taken with and without grey card calibration, as described in the Nikon Guide to Landscape Photography, using the grey card supplied in the rear cover of this book

No calibration
DSC_2960 by andrewwright4, on Flickr

With calibrartion
DSC_2973 by andrewwright4, on Flickr

No calibration
DSC_2969 by andrewwright4, on Flickr

With calibration
DSC_2974 by andrewwright4, on Flickr

The images are not identical composition,as I took them hand held, just as similar as I could get them.

 

[Whippet]

I think lightshipman is using a grey card to set exposure as opposed to setting correct white balance which is what the OP was posting about. I'm guessing the blown out images are taken at a long shutter speed which is why they are blurred. I'm guessing he is using auto setting which is why the first image is so bad, either way it's the wrong end of the stick for this thread!

 

[GardenersHelper]

nick,
Im afraid the photos are really mixed up, thay should follow a more logical sequence with firstly a shot taken just by switching the camera on and taking the shot in aperture priority, using the cameras normal auto mode, the next one should be a similar shot but after having calibrated my camera with the grey card on the table at the side of the subject,

Ah, I think I understand; we are doing different things. You are using the grey card to create a custom white balance for the camera to use for your "with calibration" shots. In contrast, I am leaving my camera in Auto White Balance mode, and using images of the card to alter the white balance when post processing.

Am I right in thinking you aren't changing the white balance when post processing the images?

 

[GardenersHelper]

I think lightshipman is using a grey card to set exposure as opposed to setting correct white balance which is what the OP was posting about. I'm guessing the blown out images are taken at a long shutter speed which is why they are blurred. I'm guessing he is using auto setting which is why the first image is so bad, either way it's the wrong end of the stick for this thread!

Our posts crossed.

I did wonder if it was a grey card exposure setting, but I'm not sure yet. See my previous post. But you might well be right.

 

[arad85]

Just to note... a grey card will get your exposure and white balance right, but it won't do anything for the way your camera represents colour. You need the colour checker passport (or similar - I have no idea how accurate the CPP or other cards are) to be able to manage that.... It isn't subtle either in some circumstances either....

 

[lightshipman]

Ah, I think I understand; we are doing different things. You are using the grey card to create a custom white balance for the camera to use for your "with calibration" shots. In contrast, I am leaving my camera in Auto White Balance mode, and using images of the card to alter the white balance when post processing.

Am I right in thinking you aren't changing the white balance when post processing the images?

Yes that's correct, and I am trying to correct at the camera stage rather than at pp. and yes it is the exposure that is getting calibrated, one thing this thread has got me doing is taking a better exposed image more constantly.