If I shoot tranny in a controlled situation, (e.g. let's say I am copying flat art using two lights, each at 45 degrees), if my lightmeter/camera settings/film/E6 lab are all in sync, I can shoot any numbers of artworks of differing degrees of light and dark under the same shutter/aperature combination and every tranny will be as near as dammit to bang on.

With digital, I can use a grey card to correct the colour balance afterwards (in the RAW converter, or PS) and apply this setting to all the images. Fine.

But, how can I get corrrect density?

If I take care to expose to the right, the exposure will be OK. But, afterwards I will almost certainly have to adjust the sliders in CaptureOne (in my case) to get that level of density/contrast/saturation that tranny produces straight off the bat.

And while these settings are in built in a tranny, so to speak, they will almost certainly vary for each digital image of an artwork.

Worse still, in the tranny I know that the painting was 'that level of yellow' no brighter, no darker. However, when I am processing the digital files and I don't have the artworks to hand, how do I know how dense (light or dark, if you will) the colours were?

If the grey card can be used for all of this, what RGB reading should I be setting it to? 127? This almost always looks to bright for me.

Also, having exposed to the right, I find that moving the dark tone (left slider) to the right, as far as the beginning of the histogram, helps improve saturation/contrast. Ditto, moving the middle slider to the right, taking it from 100 to around 85/90. Do others do this? And do you leave the right slider alone, or would you move it into the histogram too? On balance, I find that bracketing the histogram between the left and right sliders first and then finishing off with the middle slider, gives me the best result. But, overall correct brightness/density is still a bit of a mystery.

In summary, shooting artwork is about as near to all science and no art(!) as photography gets! ;-) Tranny allows the creation of predictable and repeatable results AND it provides an 'off-site' reference for later reproduction - as printers keep telling me! (Let's not even go into the debate about whether I should release the files as RGB or CMYK!).

How can I get the same consistency in digital?

D.

OK, seems like there aren't too many people concerned about density! ;-)

I guess that many people are shooting the likes of landscapes and portraits, so that 'when it looks right, it is right'. Objectively correct colour balance and density aren't really an issue like they would be when photographing table-top product in a studio (when the tub of yoghurt needs to look exactly that shade of green and no other!) or, as in my case, artwork for reproduction.

So, let me summarise what I wrote in my original post and ask if it makes sense.

There are two issues. Colour balance and density. Here I am only interested in density. e.g. how bright/dark should that yellow be?

As a means of arriving at density, does this make sense?

In C1 (I always use C1. I hate the histogram in Camera Raw. No grid, no numbers and no sliders attached. In addition to which, it isn't near as sharp on my screen as the C1 histogram. Very muddy in fact. But, I realise it's horses for courses.) assuming that we have exposed to the right (ETTR):

1. Move the right slider to the left until it reaches the toe of the histogram, but without overlapping it in any way. Moving it to the right will usually be necessary because opening up the camera an extra 1/3 during shooting would have pushed it into overexposure. The slider permits much smaller increments.

2. Move the left slider to the right until it reaches the left toe of the histogram. This will usually be around the 33/37 mark. (Again C1 wins out for me here since the toe is very visible and the warning feature is very sensitive.)

Your image will now look a lot punchier. It will have a bit more contrast and a bit more saturation. All we have done is to move both sliders to their logical extremes. i.e. in as far as they can go without blowing highlight or shadow, but no further.

In essence, what we have done is to set the white and black points manually with the sliders, rather than use the eye dropper. Much more accurate for critical work, in my opinion.

The problem is the middle (mid-tone) slider. We have no indicated point on the histogram to where we can move this one which would us that final 'tranny' look.

Or do we? Here's a suggestion....which works best for studio based work.

Shoot a frame (in the same light, obviously) of a Gretag Macbeth Colour Checker. I am suggesting this product because the correct values of each patch (not the ones that Gretag issue which are considered incorrect) are available here..........

http://www.creativepro.com/story/feature/21351.html

With this image to hand..........

3. Adjust the left and right sliders on the Gretag image (as described above)

4. Now move the middle slider to the right until the RGB values of the mid-grey at the bottom of the checker are as near as possible to 104/104/104.

5. Read the numerical value of the middle slider - usually around 85-95 - and apply this value to your first image. This should add the final touch. You now should have an image that has the punchy, saturated look of a transparency.

Make sense?

D.

Dinarius,

It seems that you answered your own question? Or am I confused?

Let me suggest one thing. When you photograph an artwork, you are using your camera which probably has subtle differences in terms of color, etc. from the camera used to capture the gretag macbeth chart you are using from CreativePro. More importantly, though, your ISO, Aperture and Shutter Speed setting will be different. Even more importantly, the color temperature and intensity of the lighting you use will be different from the file you download. Therefore, any corrections you make to the chart you download will only be applicable to your own work if the chart you download was shot using the same camera settings and lighting as your artwork.

The solution? Get your own Gretag Macbeth Chart. Set up your lighting, etc. and shoot the artwork. When finished, replace the artwork with the chart and photograph this. Then, in C1, process the image of the chart as you said in your post. Apply these settings to your images shot under the same lighting and you should get pretty close to the actual color and density information of the actual artwork.

Of course, if you want absolutely the best reproduction you can get with your system, you should use C1 to calibrate your camera by shooting your color chart under the same lighting as your artwork and comparing it to the color chart you downloaded from CreativePro. Use the sliders to make the color balance, color patches densities and monochrome patches densities of your chart match the ones from the downloaded chart. Make sure you are using the actual RGB values, not your eye, to make these changes.
I'm not sure where you enter and save these settings as a profile in C1; in ACR it's under the Calibrations tab. After you have saved a profile for your camera in that lighting, open your artwork images, apply the profile, and then use the sliders to match exposure, shadows and gamma (density) in the way you stated in your post. This should give you the most accurate color and density possible with your system.

I'm sure others are going to come along and correct me here. I'm not a pro and I'm still learning, too. The above info and the info I posted in my response to your other post all came from Real World Camera Raw by Bruce Fraser, which has been, for me, invaluable. Perhaps someone can make a book suggestion for C1?

I hope this helps more than it confuses.

Jason

[quote=Jason Cory,Mar 4 2006, 06:19 PM]
Dinarius,

'It seems that you answered your own question? Or am I confused?'

Yes, I have. I simply wanted confirmation that what I was doing was making sense.

'Let me suggest one thing. When you photograph an artwork, you are using your camera which probably has subtle differences in terms of color, etc. from the camera used to capture the gretag macbeth chart you are using from CreativePro. '

Apologies for any confusion, but of course(!) I am using a Gretag Macbeth chart which I have photographed myself. I am only using Bruce Fraser's link for the RGB values, rather than using the RGB values that come with the chart. Those are considered to be incorrect.

'I'm not sure where you enter and save these settings as a profile in C1; in ACR it's under the Calibrations tab.'

Yes, I have tried this in the past with ACR. However, I prefer to correct after each shoot. These calibration techniques work best when the lighting is repeatable, in my opinion. This isn't always possible.

Thanks for the reply.

D.