I have the opportunity to do some cave photography on a photographer's tour in which there will be tripods allowed, plenty of time to shoot, formations illuminated, etc. I have always shot Velvia, Provia, or Kodachrome for my landscape work but am wondering if one of the newer print films would work better for this application, particularly in view of the exposure latitude. Can anybody make any recommendations, or comments from experience? I'm interested in ultimately producing a few prints as large as 20 X 30 inches, maybe a bit smaller. I use Leica M. Thanks for the advice.

-- Ronald Blachly (theblach@swbell.net), January 29, 2002

Answers

What is the light source going to be?

-- Andrew Schank (aschank@flash.net), January 29, 2002.

I have shot caves with Velvia in the past. Two things to remember though: One, you will need a very good quality meter, preferably a hand-held spot meter; Two, you will need to compensate for whichever film you use reciprocity failure as well as add the appropriate filtration for color correction.

With Velvia, you need will need to add 1/2 stop for any exposure over 4 sec, and double any exposure time over 60 sec, and add 10 to 20cc magenta filtration. I do not recommend exposures longer than 6 minutes on Velvia.

As for color negative films, due to reciprocity failure, they almost all fall down to an effective ISO of about 25 at long exposure times, so there is little to be gained, IMO.

Hope this helps,

Today, I would probably use Provia RDPIII or Kodak E100S. I don't know the reciprocity/filtration factors for either of these films, but I suspect they are more pliable than Velvia. The appropriate data can probably be obtained off of the Kodak and Fuji websites.

-- Jack Flesher (jbflesher@msn.com), January 29, 2002.

Andy asked a very important question while I was posting -- my response assumes available light or avialable light combined with fill flash.

Sorry,

-- Jack Flesher (jbflesher@msn.com), January 29, 2002.

How much available light is there in a cave?

-- Phill (philkneen@manx.net), January 29, 2002.

Phill:

Depends on the cave, and how far in you go.

:-),

-- Jack Flesher (jbflesher@msn.com), January 29, 2002.

Depends on the light source in the caves of course but that can be filtered. I would look at Sensia or Provia 400 which will give you room to filter. cheers!

-- Don (wgpinc@yahoo.com), January 29, 2002.

The cave is several hundred feet underground so all the lighting is artificial. Since they're not open today I haven't been able to find out what kind of light sources they use. Having not been there in some time I'm not sure, but I remember large flood lights in front of different formations that came on immediately when switched on.

I have an accurate Gossen Luna Pro in addition to the meter in my M6. Lenses to use include 21/4 Voigtlander, last version 35 Summicron, current 50 Summiron, and current 90 Elmarit-M.

Would the Provia mentioned above be grainless enough when enlarged and would blacks be truly black?

-- Ronald Blachly (theblach@swbell.net), January 29, 2002.

Sorry, make that a 25/4 Voigtlander.

-- Ronald Blachly (theblach@swbell.net), January 29, 2002.

I don't really think you need special preparation. In my experience if the cave is illuminated by lights (most are, and if they are not, then they are not very interesting as photo objects) you can just treat it as room (albeit large) interior or a floodlit building. I doubt it will be too dark to meter properly as if it was that dark, you would have a difficult seeing much anyway. But if you can I think I would try take a good incident-capable meter. The slide films would all work reasonably well, although I suspect you will get reciprocity color issues with Velvia and Kodachrome more than with Provia. But actually I would just live with them, unless you have some reason to want it to really look like it is. You will need to bracket a good deal. Same deal really with print film. The biggest pain you will have I suspect is people moving during time exposures: not much you can do about that. A wide angle is best in my experience as detail shots suffer from problems of the viewer not understanding the scale of the image which can limit their appreciation.

I am not a big fan of most caves, I find the lighting arrangements and the commercial side of it slightly tacky and disappointing. The best caves I have seen were in Gibraltar and they were really huge spaces.

-- Robin Smith (smith_robin@hotmail.com), January 29, 2002.

Ron:

If you are unsure of the lighting source, transparency film can be a real problem if you expect to get accurate colors. If they use tungsten floods, then you can filter for it with an 80A or 80B depending on the amount of warmth you want present in the final image. If they use flourescent lights, you need to find out which type to accurately filter for them -- but an FL-D or FL-W will usually get you pretty close. If this can be determined beforehand, you can use the proper filter and expect pretty good results from Velvia or Provia. If you cannot determine the specific light source ahead of time, you will be better using a color negative emulsion with either the 80B or FL-D, as additional color corrections can be madeis at during the printing stage.

Your incident meter is not going to be of much help unless you have the ability to get your measurement directly at the subject, and IME you are often prevented from getting too close to unusual or fragile formations.

Lastly, people moving in front of your camera during a long exposure (over 60 sec) will not create any problems as long as they keep moving and are not lit frontally by any direct light source.

Have fun!

-- Jack Flesher (jbflesher@msn.com), January 29, 2002.

Hey Ron- I remember seeing a lecture presented by a fantastic cave photographer- Kevin Downey of Northampton MA. His technique, basically, was to leave the cave in total darkness. He would set up with flashlights and leave the camera open, then walk around the room, using a dim flashlight (always pointed in the same direction as the lens, so it wouldn't register on the film) and to strategically pop flash bulbs- yes, old school flashbulbs- in a few spots- whatever was neccesary to propery illuminate the cavern. Now I realize that in the situations you will encounter you will almost certainly not have the luxury (or materials) to work like this. But you might find a way to adapt this technique- such as a long cord on a flash, point it in different directions and pop several 1/30th exposures keeping the flash coverage in different dirrections each time. This might help, too, with other visitors, as long as you shoot the flash at one area or another when it is clear (or not, as you like). Using a technique like this, you could also basically ignore any existing light, since at, say 1/30th or 1/50th and f5.6 or f8 it might not even register. This could yeild some really interesting results- you won't see the caves lit in daylight, but the photos you get back will (theoretically) have daylight balanced illumination.

I suggest testing to see how far you need to move the flash to get even coverage at several pops. Also, of course make sure you have a secure tripod...

I hope you can try something like this. Let us know what results you get, however you shoot.

In anycase, you can see some of the photos of Kevin Downey - and a number of other excellent cave photographers at: http://www.bostongrotto.org/Grotto/bg-photos.html

Good luck, and enjoy!

-- drew (swordfisher@hotmail.com), January 29, 2002.

Thanks everyone. So is the consensus that the new Provia 100F (RDPIII) is the film to use? Assuming I get my exposures right and use any necessary filters, how enlargeable (with good technique) will these be? And will the blacks be black? What if I push it one stop?

Finally, if lighting is tungsten and I don't have or can't get the filters in time, what would results be like if I use Ektachrome 160 or 320 Tungsten?

Thanks again.

-- Ronald Blachly (theblach@swbell.net), January 30, 2002.

In my experience Provia 100F (RDPIII) is the finest grain sharpest (and thus most enlargable) slide film out there.

Anyone have a different answer?

As far as pushing it, I have got good results from a rating of 200 and a straight-forward +1 push.

-- drew (swordfisher@hotmail.com), January 30, 2002.

Ronald:

Personally, I would not push Provia if you want to enlarge beyond 16x20. When rated normally, I think you can go up to 20x30 IF you use a very sturdy tripod and near-perfect exposure technique, AND you don't expect people to view you final print from closer than about 1 meter. Also, I would not use any Tungsten emulsion unless you are familiar with how they work beforehand. Lastly, I'd experiment under Tungsten light with the Provia and the 80A and 80B filters beforehand to determine which result you like best -- they are about 200* K apart in temperature.

-- Jack Flesher (jbflesher@msn.com), January 30, 2002.

Ronald, Give my Salamaleks to Osama when you meet him at home there....

Well it's as dark as night with reflexions from the walls.

Indirect lighting? Flash meter?

-- Xavier d'Alfort (hot_billexf@hotmail.com), January 30, 2002.