View Full Version : projecting images for an illustrated lecture

Henry Carter
26-Sep-2004, 21:19
I have to give an illustrated lecture to a group of about 400 people. My talk involves speaking about and showing images that I have documented with my 4X5 camera. When speaking to smaller groups I have used a set of matted 16X20" prints on two easels with lights, and this has worked well. This approach will not however work for speaking to larger groups.

For a presentation to a large group I have two options:

(1) Scan my 11X14" portfolio prints and project jpegs with an LCD projector as part of a power-point presentation, or:

(2) Make 35mm transparencies (i.e. photograph my prints) and project them optically.

Which route should I take??

Louie Powell
27-Sep-2004, 04:54
This is the 21st century. I would opt for the powerpoint presentation, recognizing that the optical quality won't be quite as good, but the flexibility that comes with powerpoint is a read advantage.

However, I would also take along a selection of prints that could be use to illustrate the quality that comes from LF and that can be used to engage members of the audience in dialog following the formal presentation.

Robert A. Zeichner
27-Sep-2004, 05:15
I recently made several sets of B&W slides using T-max100 and processing with Kodak's Direct Positive kit. Results were excellent. A kit will do (10) 36 exposure rolls as I recall.

27-Sep-2004, 06:12
I would just shoot the prints in some color slide film on a copy stand and be done with it. Either bracket or make a test roll and let some automatic processor deal with it.


David A. Goldfarb
27-Sep-2004, 07:16
I do the same as Lee--shoot 35mm copy slides. The optical quality is much better than LCD projection, even with a relatively cheap projector. Most art historians I know who lecture with slides all the time still prefer slides for most things. The only time I would be tempted to use Powerpoint would be if the talk would otherwise require more than two projectors.

John Flavell
27-Sep-2004, 19:03
Always take prints. People love prints, especially if they're allowed to hold them and talk about them.

Henry Carter
27-Sep-2004, 19:06
Thanks to all for your input. Given that I work in B&W with a 4X5 camera and make fibre based prints, it makes more sense to maximize the projection quality by using 35mm transparencies.

One of our local labs has a Scala processor, and they can make Scala copy slides. The other local labs make copy slides with color transparency duplicating film. I assume that Scala is the better option.

David A. Goldfarb
27-Sep-2004, 19:25
I'm not sure, really. If you have time, you might do a test, or ask the lab what they think. Scala is really beautiful, but I'm guessing it will pick up more contrast than dupe film.

Henry Carter
27-Sep-2004, 19:36
That's a good point. The lab can pull the Scala to flatten the contrast a bit. I have the time to do some testing. I will take the same two prints and have Scala copy slides made in one lab and then have another lab make copy slides with duplicating film. I will need to have 50 to 60 slides made for my lecture.

Ralph Barker
29-Sep-2004, 00:46
Another option to Scala, Henry, is any of several conventional B&W films that process well in dr5 to produce B&W positive transparencies. See www.dr5.com for details and examples with various films.

Emmanuel BIGLER
29-Sep-2004, 05:00
Henry. As far as I understand, your originals are B&W large format negatives and you wish to show a high quality B&W positive preview of the images to the audience.

Then, you could directly make positive copies of your negatives on a special 35 mm film named Eastman Fine Grain positive. My understanding is that this film is intended for copying B&W negatives for the movie industry, but it has exactly the right contrast and tonal range to deliver a good B&W positive slide from an original B&W regular negative. I have no idea whether Big Yellow still has the film on catalog, though. The film was (is ?) available only in bulk 35 mm rolls. I remember, may be here, having read about a professional B&W portraitist in the US who makes a positive 35 mm B&W slide from his negatives to show his clients with a regular 35 mm slide projector, so that they can chose their preferred portrait before actually printing it.

Henry Carter
2-Oct-2004, 22:24
I have had copy slides made, and here are my impressions:

I took the same three B&W fibre prints to two different labs to have copy slides made. One lab used Kodak duplicating film (a version of Ektachrome 64?) and the other lab made dupes using Scala (pulled one stop to reduce contrast).

I have compared the results by projecting them with a slide projector. The biggest difference is that the blackest areas of the Kodak transparencies tramsmit some light, appearing dark brown instead of black, whereas these dark areas are totally black in the Scala dupes. This gives the Kodak dupes a slightly washed out look, whereas the Scala dupes have a look and DMax much closer to the original prints. The Scala dupes have a little more contrast and perhaps a slightly compressed tonal scale. The Kodak dupes are perhaps more open, but part of this is an illusion because the darkest areas transmit some light and have a brown color cast.

Both films give acceptable results, both are sharp, and they both have a tonal richness and detail that is far superior to projecting a digital file with an LCD projector.

Brian Stein
11-Oct-2004, 22:16
I am not sure if the originals were colour or B & W. If the former I wonder about the possibility of using an 'overhead' type projector with the whole 4x5 slide? Has anyone tried this?