Camera dynamic range issue

[RobinFaichney]

This might be my fault, I don't have a terrific amount of experience. I use a Canon 5Dii and I'm very happy with the results generally, but not for copy photography. I have studio flash and the problem is basically the same whether exposing according to the flashmeter or using trial and error to match the white paper of the original. I think colour is probably OK -- camera, display and printer/paper are all profiled and calibrated -- but despite trying all kinds of adjustments in Lightroom, when most tones look right, I can't get white to look anything other than dull, or if white is bright enough, other light tones are too light. Also, a test image, properly exposed, when reprinted without adjustment has both black and white leaving something to be desired. Reading back I realise this might look like a Lightroom issue, but I've spent a fair bit of time massaging tone curves and I don't think the answer's there. I suppose I could still be missing something there though...

[D Fosse]

Just guessing, but perhaps Lightroom is choking on a bad monitor profile?

Do you have a ColorChecker passport or similar? That could give a clue. I always include one in repro work. The gray patches (well, all of them) have standardized values in Adobe RGB / sRGB, which are relatively straightforward to translate to Lightroom % values (via soft-proof). So if you set the sliders accordingly and it still doesn't look right, you know something's wrong.

[digitaldog]

Be helpful if you could provide a same raw image (I assume you're capturing raw).

[bill t.]

Are you dissatisfied with the files, or the resulting prints?

I have done a lot of 5D2 copies of my wife's colorful pastel pieces using sunlight, and for that reason I create a Colorcheck Passport camera profile just before shooting the piece.  In LR, I usually have to do nothing except take the saturation down a bit.

The printing media imposes the biggest constraints, since that's where you get tension between the color gamut described by the original art and the color gamut available on the media.  One solution is to pick a media that's a good match for the original.  For instance matte media often has trouble in the blues, reds, and violets when the original is very saturated in those colors, and may have a lower contrast range than the original which squeezes all the tones.

[RobinFaichney]

Thanks for all the comments so far, but Andrew's suggestion re the raw file seems most promising, so many thanks to anyone who's willing to take the time to look at it, please PM me with your email address (or suggest a better way of sharing -- I'm thinking of using http://sprend.com/).

[JeanMichel]

I do a larger amount of artwork documentation, and I use a 5d2 too. A ColorCherker or similar device is essential. You also need polarizing filters over your lights and on the lens.
Jean-Michel

[RobinFaichney]

I do a larger amount of artwork documentation, and I use a 5d2 too. A ColorCherker or similar device is essential. You also need polarizing filters over your lights and on the lens.
Jean-Michel

I have Colormunki Photo and have profiled and calibrated camera, monitor and printer/paper using it. Can you explain the function of the polarizing filters please, I've not come across this before. But now it occurs to me, maybe it would eliminate reflections off glass, which I don't encounter.

[NancyP]

You can polarize your lights and use a polarizer on your camera to completely eliminate reflection.

[RobinFaichney]

You can polarize your lights and use a polarizer on your camera to completely eliminate reflection.

Thanks. I've avoided glass so far, and gotten around other difficulties by careful positioning of lights and use of diffusers, but I can see that this would be very useful in some situations.

[digitaldog]

Looking at the raw, I suggest you do a bracket, add more exposure. Everything looks down to me, you're far from ETTR even though this isn't a noise issue. I don't see this as being a dynamic range issue, seems if anything, the image in ACR defaults looks pretty muddy, if anything it needs more contrast and exposure. Try upping exposure ½ a stop till you are a good stop and a half over the original and see if that helps at all. Everything appears a bit cool too but WB and further adjustments perhaps with tint/temp will help. And do consider putting a Color Checker into the image outside the frame to aid in all this.

[digitaldog]

Even the much maligned "Auto Tone" with custom White Balance seems IMHO to improve this a great degree.

[JeanMichel]

I have Colormunki Photo and have profiled and calibrated camera, monitor and printer/paper using it. Can you explain the function of the polarizing filters please, I've not come across this before. But now it occurs to me, maybe it would eliminate reflections off glass, which I don't encounter.

Hi again,
Polarizing allows you to control, or even eliminate, reflections. In some cases removing all reflections can make a textured painting look too flat, so judicious use is required. Fort work behind glass, either remove the glass or photograph through a black  curtain; polarizing filters will not remove reflections from glass surfaces. The black curtain a good practice
for all works in any case. 
Jean-Michel

[RobinFaichney]

Thanks Andrew, I think I've gotten my head around this now. My previous experience was like bill t, copying artwork using very few adjustments, and I got to think that was normal, but the difference this time is the target has a much wider tonal range, so I have to bump contrast etc. I can see, to many people here, that will probably look pretty stupid, but at least I've learned now! Thanks also to all other contributors, this has been a valuable experience for me.

[Vladimirovich]

Also, a test image, properly exposed

to check if your raw was indeed properly exposed you need tools like rawdigger (www.rawdigger.com)

[digitaldog]

to check if your raw was indeed properly exposed you need tools like rawdigger (www.rawdigger.com)

That would be ideal but not necessary, the OP could bracket and then assuming the setup is consistent, he's all set once he finds the best setting.

Do you analyze every image you shoot raw with that tool? Seems like overkill.

[loosecanon]

The problem is the dynamic range of the paper image is less than that of the camera.
What is essential is to record all the detail on the page that is required, this will give you grey whites and maybe grey blacks.
When copying make sure lighting is very even across the image, as the next stages will show up any irregularity. Also use a good prime lens to reduce vignetting. I use two lights.
Once you work out correct exposure take all images with the same exposure.
In lightroom adjust to get image as you wish - levels will bring blacks to be black and white to be white. If necessary fine adjust with curves. Take your time to get it right, remember you can use the eyedropper tool to set whites and blacks etc.
Then apply these adjustments to all the images.