Luminous Landscape Forum
Equipment & Techniques => Digital Cameras & Shooting Techniques => Topic started by: rickster on October 06, 2004, 09:02:40 am
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[font color=\'#000000\']Thanks Guys...
I think my biggest concern is lighting and how to control it. Polarizing is a good idea. I’ve already decided to profile my camera with something like “In Camera”, My monitor and printer are already profiled. Since I have a lot of shots to make and this will be an ongoing project I need a repeatable set-up so outside is out. I was thinking of using two ordinary fluorescent light fixtures, one on each side.
Do you have a source for a polarizing material?[/font]
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[font color=\'#000000\']Flash with a modeling light will provide the steady light that is useful in making copies.
Hard or diffused light can be approximated using a hard light that is closer (more specular) or father away (more diffused) from the subject.
Using two lights, one on either side, is best. You can show surface details by making one light stronger than the other. With side lights, you may not see horizonal texture as well. You may want to try top/bottom or angled lighting.[/font]
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I do a lot of art documentation too.
An easier way of aligning the camera and the painting is to use a spirit level.
Simply take a reading from the painting by holding the level against the frame. Now hold it against the front of the lens and tilt the camara until the reading is the same.
The film/sensor plane and the plane of the artwork are now perfectly parallel.
Occasionally, I will have to photograph an artwork which cannot be moved (too valuable!) and is at an angle too acute for the spirit level. On these occasions I use a plumber's angle setter.
With the exception of my light meter, the spirit level is the most used piece of equipment in my bag!
D
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Thanks for the link, Jonathan, I've been looking for a good reason to buy a Macbeth card!
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If you have Photoshop CS, you can automate the process of color calibrating ACR by going to http://fors.net/scripts/ACR-Calibrator/ (http://fors.net/scripts/ACR-Calibrator/) and downloading Tom's calibration script.
I downloaded and ran the script last night and it worked perfectly, (it took <50 minutes).
Man does it make a difference.
Thanks J...
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For those of you who are interested, here's a sample using the setup from the previous post. Converting to web display really is an injustice though...
(http://www.rickowens.net/I-Think-Therefore-I-Am-LL-.jpg)
Not too bad but still looking for improvements. The next problem is finding a ink paper combination with a large enough color gamut.
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[font color=\'#000000\']Does anyone have any experience shooting art work? I have about 50 paintings I need to photograph. Color rendition is high on the priority list, so I was thinking along the lines of “In Camera” for profiling the camera. I don’t know anything about studio lighting but if I’m profiling I assume the light temp doesn’t matter. Any suggestions would be appreciated.
Thanks.[/font]
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[font color=\'#000000\']Ordinary fluorescent lighting would be the worst possible choice you could make. Most fluorescent lights, even those that are rated as having a daylight color balance, emit light in only a few discreet frequencies. You want a light that covers the whole visible spectrum. Also, fluorescent light varies through the course of each cycle of AC power. To get consistent, repeatable results, you need to use a shutter speed that is an even multiple of the power cycle time, e.g., 1/60, or 1/30.
Try using two flash units mounted off camera or invest in a studio lighting set-up. Make sure that the walls and ceiling are all neutral colors or you will pick up color tones from the reflections.
Most pro photo shops should have the polarizing filter material for the lights.
You don't say much about the purpose of your project, but I have found that many or most art exhibits, etc., want to have slides submitted to judge and select the artwork that is submitted for possible exhibition. Although it is possible to get slides made from a digital file, it is also expensive. I do most of my own shooting digitally, but I shoot copies of my wife's artwork on slide film because it is much cheaper in the long run. Bracket liberally and take several shots at each exposure setting so you have some good duplicates if the artist needs to submit slides to different shows.[/font]
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[font color=\'#000000\']Oh, and do all this in a room where ambient light is low so you can see in the view finder about what you will get on film (or sensor).[/font]
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[font color=\'#000000\']If you have a limited lens selection, you might try an extension tube or close-up attachment for a longer lens.
Take a lot of data (location of lights and camera, exposure data, etc.) when you start. Your results should be quite repeatable. You can reduce bracketng (= save money and time) the next time through.
The suggested in-camera dupe is a great idea. Saves a lot of money and some really fussy types may require an original, not a copy.
If you use hot lights that flicker at the line frequency (60cps in the US and some other palces), use a longer shutter speed than even 1/30. The flicker is very accurate but your shutter speed may not be. 1/30 is only 2 cycles. If your shutter is offjust a bit, you could get a band. I use at least 1/2 second.[/font]
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I have copied thousands of paintings and i think that film is far better than digital[its all about accurate color after all,isn't it?]
That's a quite unjustified assumption if you've bothered to implement good color management in your digital workflow. Digital can deliver much more accurate color than film if used properly. If you have Photoshop CS, you can automate the process of color calibrating ACR by going to http://fors.net/scripts/ACR-Calibrator/ (http://fors.net/scripts/ACR-Calibrator/) and downloading Tom's calibration script. Shoot a Gretag-Macbeth Color Checker, and run the script on the resulting RAW file. It'll take 1-2 hours to run, but the results will pay off for a long time. You can save the calibration settings as your camera default.
I have a 1Ds, 1D-MkII, and a 10D, and calibrated them all using this tool. I get a very similar look no matter what camera I use, which is very handy when shooting a job with multiple bodies.
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Will the Calibrator mentioned above work with Photoshop Elements?
AFAIK Elements does not include Camera RAW 2.3, so no.
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[font color=\'#000000\']If perfect colour accuracy is required, you'll need a completely calibrated system from camera to printer. I'll leave that subject for others to advise.
As for lighting, I've had great luck shooting artwork outdoors. On a cloudy day, the light is sufficiently intense and is of constant colour temperature.
It's also very easy to set up and strike and the rental rates are great.
P[/font]
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[font color=\'#000000\']There are a few more considerations if your endevour is critical...
1) Lens distortion (barrel, pincusion, CA, field curvature, etc.) can alter a true representation of the piece. Traditionally, "process" lenses are used for this type of copy work. A good alternative is an enlarging lens, but then you need to rig up a shutter. If your goals are less critical, at least try to use a prime macro lens.
2) You need to decide how you wish to represent any surface texture in the copy. Do you want to show the brush strokes and canvas or not? If you do, you need "hard light" and experimentation. If not, you need diffuse light (which tends to polarize poorly).
3) Strobes will give you a truer color representation than quartz lights, but it is really hard to work without constant light on the artwork (at least for me).
4) Grey card shots should be considered mandatory.[/font]
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[font color=\'#000000\']Thank you all very much, this kind of information is what makes this forum so valuable.
I didn't think about the effects of line frequency vs. shutter speed, nor the limited frequencies emited.
I have a limited lens selection so maybe this is a chance to try out DxO.
I like the tent idea, and the mirror for alignment.[/font]
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Dlab,
Do you have a link to "Copying and Duplicating in B/W and Colour"?
Many thanks.
D.
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It takes a long time trying really stupid settings before getting it right, but other than that, it works reasonably well. I sent the author some suggestions on how to make it faster and more accurate, but haven't heard back yet.
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Can anyone recommend default USM settings for images of paintings?
I usually deliver 18mb/11"x17"/180dpi files.
Is it possible to use a standard USM output for this size of file, or is it really case dependent?
Like many people before me, the dark art of USM is the thing I find the most impenetrable! ;-)
Many thanks.
D.
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My set up for copying artwork:
4 flash heads 2 on either side at a 45 deg angle
As long a lens as possible
Balance the lighting with a flash meter so center and all corners are identical
I use polarizing filters ont the heads and the camera if the subjet has reflective highlights
the amount of texture in the shot is controlled with the pola filter on the camera
Use a level on the original and the camera
I set a line of masking tape on the floor to help align artwork and camera
the mirror trick works as well
shoot a macbeth color checker every time you change image size as this will help you correct for exposure loss of light due to close focus
I hope this help
Paul lamontagne
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[font color=\'#000000\']The biggest issue with reproduction, particularly with oils or acrylics, is lighting and reflection control. Good WB (including grey card shot) may be adequate for color but obviously profiling may do even better. Use two lights (one off to each side) and if necessary polarize the lights and cross polarize the lens to control reflections. As already suggested I've also had good luck outdoors but if you're doing a number of works changing conditions can make it a lot more difficult to adjust as each has to be done individually.
- DL[/font]
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[font color=\'#000000\']We do a lot of this, including slides for entries as described by jdemott and digital files for prints. We don't polarize, but the material is available in sheet form from most pro lighting stores.
As for lighting, we use two off-camera strobes w/ or w/o soft boxes- doesn't seem to matter and not worth adding or removing from the lights. That's because of the most important detail of the setup: A plain old king-sized bed sheet. Not available at photographic prices from camera stores, so you have to pay a lot less for one at a discount or department store. ::
You need king sized so you can pin the midpoint of one end to the wall above the painting and out of frame. Drape the remainder out and over the camera and tripod (your second tent pole), and pull the sides out and away from the setup, draping them over something or weighting them to the floor if you don't mind working on your hands and knees. Now you have a large light tent. Hit the sides with your strobes and you will have incredibly uniform lighting and no reflections from oils. A strobe meter is really helpful, but even with that it is still a good idea to BLH. (bracket like heck).
This setup should be really useful to you with so many paintings to shoot. Simply slip in and out of the tent to exchange one painting for another and keep shooting.
Hope this helps![/font]
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[font color=\'#000000\']One trick for getting the camera aligned perfectly perpendicular to the artwork:
Put a mirror in the easel/frame/table where the artwork goes, and align the camera so that the center of your lens is in the exact center of the viewfinder. You'll be perfectly squared up, and won't get any perspective distortion.[/font]
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A lot of valuable informations can be found in Kodak publication:Copying and Duplicating in B/W and Colour.I have copied thousands of paintings and i think that film is far better than digital[its all about accurate color after all,isn't it?].good luck
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Hey Jon...
I'm very interested in this script. I see that's it a beta release, have there been any issues during use?
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another question.........
Will the Calibrator mentioned above work with Photoshop Elements?
Thanks.
D.
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This is what has worked best so far...
1. Shoot in garage at night. Tried the attic but way too much vibration.
2. Use a ladder as a tripod. Crude but effective. My tripod is not good enough to hold a 20D with a DO 70-300.
3. Level the camera with wood shims. Again, crude but effective.
4. White bed sheet on the floor in front of the painting.
5. Lighting... This is the tricky part. The only thing that I have found to work are the overhead fluorescents (four tubes that came with the house) and two screw in fluorescents in hot light fixtures pointing up. The camera is about 12-15 feet from the painting and the lights are midway between the two. Not a lot of light but no glare either. The polarizer didn't seem to help much, maybe a little. I have to make sure the lights have warmed up before shooting. This might be an issue as it gets colder.
6. Exposure, F8 at whatever.
7. I shoot a ~40"x50" white board and then a Color Checker and then run the ACR calibrator on the CC and use the white board to check for even exposure and adjust for vignetting.
8. Shoot the painting and convert in ACR using the above saved ACR settings.
9. Open in PSCS, crop, white point, black point, capture sharpen, creative sharpen, output sharpen, print.
Looks pretty good so far, but I'm still trying different setups. I was really fighting color temp until I tried the ACR calibrator. That script works great!
I'll post a sample image for critiques here soon...