Any Kodak 64T epy users out there?

[frotog]

I just got 4 boxes of 4x5 epy from B and H. I'm shooting a repro job for a friend- big oil paintings. I'm going to test it first, of course, but would love to hear from some of you who have used this stuff before. Should I rate it at 64? Is the actual color balance at 3200? The back of the box says to use a 5cc cyan filter at speeds of one tenth of a second but no filter at longer times. Sounds kind of weird...

 

[erikg]

I have shot this film quite often. I have found the speed to be correct, and it is balanced for 3200K. However, most tungsten lamps vary some, due to age etc. so they are usually lower in color temp. (until they are about to die, when they get much whiter) Often this slight shift is not a problem, depending on the art, but it is easy to correct with a filter. Sometimes some filtration is needed to balance out the lab processing too. The film is intended for longer exposures, so it is balanced for that, hence the filter rec. for short exposures. Much like the old VPL color neg, L for long. If you are using cross polarization to shoot these paintings, (and even if you don't) you will have exposures long enough to not have to worry about that. It is a nice film, hope you have a good lab to run it.
Best,
Erik

 

[frotog]

Thanks for the response erikg. I hadn't thought of using a polarizing filter but now that you mention it it's probably a good idea seeing as how the paintings have lots and lots of glazing. I think I might have a 4x4 circular or linear polarizer (I can't remember which) around here somewhere...is there a big difference?

 

[Lee L]

Erik is talking about cross polarization between the camera and lights. That requires a polarizer sheet over each lamp and a polarizer at the lens. Typical procedure is to put a polarizer on one lamp, then one on the camera. Adjust the camera polarizer to maximize its effect on that one lamp, then procede to turn on each of the other lamps one at a time, and then adjust the orientation of each lamp polarizer in turn to maximize its effect, leaving the lens polarizer untouched. Now all the lamps are cross polarized relative to the lens and you are killing as much polarized reflection as possible.

If you use only a polarizer at the lens, you can only kill reflections that are polarized by the reflecting surface.

Whether or not you can meter effectively through a linear polarizer is a function of how your camera meter operates. Other than that, you could go with either linear or circular at the camera, or linear with an outboard meter and filter factor.

Most art copyists try to photography paintings without any glazing or frame, often on a black background, but this depends on personal preference if it's not specified by a submissions panel, museum, gallery, or the like.

EPY is the traditional "standard" for this kind of work under tungsten light. Critical work presumes that you'll be doing some fine tuning with CC filters for each emulsion batch, your lights and reflectors/diffusers, and your lab.

Lee

 

[frotog]

Thanks for the tip Lee. Your explanation spurred a few other questions. Circular polarizers allow for varying degrees of polarization at the lens hence variable filter factors, right? While linear polarizers polarize all the light coming through lens hence the single exp. factor and the ability to use a hand held incident light meter at the painting, right? I was planning on using three mole cools (little 600 watt pars) and either bounce or blow through some 216 white diffusion. Is placement of the polarizing gel on the light fixture a concern(in front of or behind the gobo/bounce card)? Do I have to rotate the polarizing gel on lights #2 and #3 inorder to get the cross polarizing effect that you guys are talking about? BTW, by glazing I meant that shiney stuff that some painters like to coat their paintings w/, not glass.

 

[gr82bart]

I use Kodak Ektachrome 64T, 160T and 320T a lot but for one application only - twilight photography. I've shot the film as long as 15 minutes with no filters and always set the camera at the rated speed.

Funny, but I've never shot this film under tungsten lights!

Regards, Art.

 

[erikg]

Lee's description of the process is excellent. Linear and circular polarizers work the same way, both are adjustable. It's just the circular ones that work best with auto-focus TTL metering SLRs. For your 4x5 that is not an issue, and the linear filters cost less. As for your lighting, when filtering this way the lights are usually used direct, without diffusion, with the polarizer placed 10-12" from the lamp to keep them from burning out. I set the lights at an angle that gives as little glare as possible, metering around the canvas and adjusting lamp distance until the lighting is even across the surface, and then I set the polarizers as Lee describes. Almost always the filters are set for maximum polarization so using a filter factor works well. That's what I do, anyway, maybe other folks have different methods.

 

[Lee L]

You can probably avoid the need for polarization altogether if your lighting setup is well done. Set up the art and camera square and centered. Note that as in the accompanying drawing, the camera sees the canvas covering a certain angle (blue lines). Take the angle of reflection, equal to the angle of incidence, and you get the two wider red lines coming back off the edges of the artwork. A light source at position "A", located inside the family of angles (red lines) within which the camera can see a direct reflection off the artwork, will cause a direct reflection within the artwork (unless it's a very diffuse surface). A light placed at position "B", outside the family of angles that get reflected, cannot cause direct reflections off the artwork (except over small areas if heavily textured and reflective). Note that a wider angle lens placed closer to the art has a wider family of angles, so the lights would need to be at greater angles from the lens-to-art axis. A longer lens placed further away from the art has a narrower family of angles and allows a greater range of safe light placement. So if you place your lights, including the entire lit surface of the diffusers, outside the family of angles (the red lines) and with even illumination across the artwork, you should be good.

You might also want gobos to keep direct light off the lens and reduce flare. A dark background (cloth, paint, seamless paper) also helps prevent flare and distracting shadows.

You can check the setup by placing mirrors in the same plane as the artwork where the edges of the painting will fall, and see if the lights are visible in the mirrors from the camera position. Give yourself a little leeway to account for any tilt in the hanging artwork.

One of these http://images.google.com/images?q=tbn:ZRZ8kgSNLfEz-M:http://www.evipaq.com/images/angle.jpg can help you set your camera square to a tilted hanging painting. No implied purchasing endorsement here, just the first googled link to a decent image of the tool. You can surely find one at a decent local hardware store.

If the artwork is large, you may need to go to two lights on each side, or back the lights further away in order to get even lighting across the painting.

As Erik mentions, there's no practical difference in using linear or circular polarizers unless they interfere with autofocus or with split beam metering setups. That's unlikely to be a problem with your 4x5. I just mentioned it for completeness, and those with other equipment reading the thread.

Lee

 

[PHOTOTONE]

Regarding reflections on paintings. Some artists really pile on the paint, to the point where there is a dimension, little spikes of paint, and these can catch the light, even if the rest of the painting is even and reflection free.

 

[Whiteymorange]

I have used this film (in 35mm) for making slide portfolios for the last ten years with very little trouble. I shoot with 3200K light only - darkened room, no stray light sform other rooms, etc. and I shoot it at the rated speed, using a gray card for the initial setting. I have had very little problem and great color fidelity no matter how old my bulbs were. I generally use a copy stand since much of the work is small, but I have also used a wall and a tripod - three lights and careful metering, again using a gray card.

One exception: In the last batch there was a magenta shift that may be due to the fact that the film was outdated or to the sloppy work of a student who didn't quite get the "no stray light" thing. He had lights in a room behind the camera on and that light bled into his shot.

Good luck!

 

[Lee L]

Regarding reflections on paintings. Some artists really pile on the paint, to the point where there is a dimension, little spikes of paint, and these can catch the light, even if the rest of the painting is even and reflection free.

Ever seen Roy Lichtenstein's "parodies" of the painters who use a tube of acrylic or oil per stroke? They are very flat, as is his style, and hilarious. The ones I've seen in person don't even have a gloss to the paint.

http://www.abstract-art.com/abstrac...gr_inf_images/g037b_lichtenstein_brshstrk.jpg

Sometimes it's good to have those catchlights in copy photos of heavily textured paintings to show their character accurately. If they are obtrusive, cross polarization might help to bring them down a little.

Lee

 

[frotog]

Thankyou...you guys are AMAZING!