Shooting large paintings, questions about lights

[Too Many Cameras]

I have a book at home with an entire chapter on this. When I get back this evening, I'll see if I can find it. If so, I'll post some tips from it.

[esox]

Thanks

[Too Many Cameras]

The book's advice isn't basically the same as we've seen with a few added details. Note that this book is from the 1950s and focuses on black and white film. It suggests two studio lights at 45-degree angles from the camera. Then it adds that polarizing filters should be on the lights. But no mention is made of a polarizing filter on the lens (that doesn't indicate that's wrong, in fact, I think a polarizing lens on the camera would be a good idea.)

For metering, it suggests a spot reading from the image's center and each corner as well as a number of random points on the subject.

I'm assuming these are large paintings and you won't be using an additional bellows, but if you are then there's some added calculation in that.

Also, if the original is closer than eight times the focal length (e.g., 80 inches for a 10-inch lens) you'd need to increase the exposure by up to 3/4 (at 1:1).

If any of these are sculptures, it suggests lighting them as realistically as possible.

That's all I got.

[lenser]

The ideal would ne a set I can ise also as light flr object sculpture pictures. And also clzssiczl studio job : portrait, artistic nude'... Ansd not too expésive, I just bought the phase one equipment... Are my wishes too ireal ?

It is not too ideal(?) a wish at all. I can't speak for the European market, but many fine used items are available in the US via ebay including the White Lightning series of flashes that are incredibly reliable and allow for quick interchange of standard reflectors and snoots, to umbrellas, and on to soft boxes. I have owned White Lightning Ultras for over 25 years and still use them almost daily. They adapt to any needs I have from the copy work we have been discussing, to portraits and commercial assignments and all with ease.

Many other manufacturers have similar mono lights that could also be used as you wish for all applications. Please note that I am very partial to mono lights as opposed to the systems that rely on a central power source that operates four or more heads. Those are very good systems and usually quite reliable, but if your power source ever goes down.....you are out of business until you repair or replace it which might take more than a few days. With the mono lights, with power already built in each head, if one goes down, you can carry on quite successfully with the rest in your kit.

The one thing that I haven't mentioned or seen mentioned in all of your answers is that in the copy work, be sure that your reflectors are all the same style and diameter and that they are set to exactly the same power and distance in order to avoid hot spots or a different lighting pattern from one side of the piece to the other on whatever you are copying.

A couple of others have mentioned melting the polarizers that are at the lights. That is a problem only if you have them right on top of the reflectors. Simply buy large enough sheets so that you can hang them several inches in front of the light (the modeling light is the heat source) and you can leave them in place pretty much all day. The big sheets keep you from having any spillage of the raw light onto the piece and six or eight inches of space allow for adequate air circulation and for the heat to dissipate upward and not fry the material. Since they do subtract light, I second the idea of swinging at least one out of the way (temporarily) for easier focusing or, just have a bright painters light beside the camera on a separate stand that you switch on only for focusing and then switch it off while doing the photography. That gives you a much brighter focus light and keeps you from having to fiddle with what should be a static set up on all of your actual copy equipment.

Regarding the separate focus light, don't set your camera's polarizer while using the focus light. Only set it while viewing the piece under the polarized light.

[Sevo]

YMMV as to whether you may photograph with flash, if the paintings are in the care of a curator - these tend to own luxmeters and IR meters to check risks, but usually won't trust the flashmeter you bring. I often had to use constant light - the focus light on my flash heads being gentle enough to satisfy the museum staff.

[Robert Langham]

I shoot this kind of stuff often with polarizer film over two lights, (dynalite heads), a polarizer on the camera and a greycard with color scale. I'd sure recommend talking them out of using large format and shoot it on digital. Seems like I bought the polarizer film from calumet. Comes in a roll. I used those little double clamps, top and bottom, to hold polarizer film an inch or two in front of a fairly big cone reflector on the dynalites, then put a stand and a black card between the light and the camera to keep glare down. Good luck, no matter what your approach. You'll really see the reflection controlled when you spin the polarizer on the camera. On the frame and the brush strokes. Be sure that both sheets of polarizing film over the lights are turned the same way! You don't want to be polarizing ONE light and UN-polarizing the other. Just clamp them in front of the lights with the curly side toward the light and the same edge up.

Helps to shoot the artwork with the longest dimension vertical between the two lights, (Stand paintings on end)....that's where the most even illumination is- a strip evenly between two lights. But then you have to go vertical with the camera as well.

I'm sure I've over-explained this.

[Bob Salomon]

Couple of things to watch out for.
1: The polarizers used on lights are heat sensitive. You have to make sure that you don't have them so close to the light source that they begin to deform or warp. They need an airspace.
A good way to determine how much space is with a piece of unexposed but developed black and white film. Just hold it in front of the light and see if it starts to deform, if it does move it a little further away. When you find the spot where it doesn't then that is how far away the polarizers should be from the light.

2: When photographing precious metals under polarized light, silver, gold, platinum, they will appear black so if they are present in the art work or the frame or matte watch out.

3: When setting the lights up the one on the left should point to the right edge of the art work and the one on the right should point to the left edge. This way you will avoid the hot spot in the center that can occur when both lights are directed at the middle of the art work or copy work.

Lastly, since you are not in the USA, you can get sheets of polarizing material up to 40 x 40cm, 0.4mm thick, from Heliopan in Munich. These are not polarizers that you can use on a lens as they are not optical grade. However you would have to make your own holding system.

As someone else suggested, a pair of clips doew work. One easy way to make your own is to make a large hole in a piece of heavy weight, black mount board, tape the polarizing gel to the mount and then mark each mount with an indicator that shows the plane of polarization.

It is easy to determine this by looking through your camera's polarizing filter at one of the lighting pols. Then rotating the lighting polarizer till you get the max. polarizing effect. Then make a mark so you know where that point is and repeat with the other lighting pol. It is important that you do not change the position of the camera pol while doing this.

Then when you are ready to use the pols just mount them to the lights so the index mark that you made is in the same position on each light. It will save a lot of set-up time when you are ready to shoot as all you will have to do is point the lights and then rotate the pol on your lens.

[Robert Langham]

Just in case you were confused by the excellence of my description: Here's a light set up with the cone, clamps and polarizer film:

[esox]

I ws a bit overwhelmed by the excellence of your technical words (excuse my french, I'm ... french...) but I'm completly subjugated by the superiority of your illustration !

Now I have to find 4 identical used studio flashes... That is a challenge ! Is it necessary that they are fully identical or equal power is enough ?

[Drew Wiley]

One thing I don't think anyone brought up yet is the need for a long enough lens to back away from the shot and not accidentally become part of it - what I mean is that some media are reflective enough
that the light will reflect onto you or shiny parts of your gear, and then back onto the subject. In a worst case scenario, you can wear black clothes and tape over the shiny things with black masking tape, or better yet, shoot through a hole in black board, kinda like making a black bird-watching blind.