5/14/96

Does anyone out there know how to make high-quality overheads from standard B&W photographs (e.g., TEM images including HRTEM images)? I have always made slides for my talks up until now. Just using the standard xerox transparencies does not give very good results, but I have seen talks where people use transparencies and they are remarkably good. Is there some trick or method I am missing out on?

Roy Christoffersen
roy@bayou.uh.edu

We switched from slides to overheads more than 10 years ago. The very high quality of our overheads from continuous tone and line copy originals is attributable to our use of VGC Total Camera III units. We have several hundred people at our site who provide work for the two or three Total Cameras here. The machines also make screened paper positives as well as positive transparencies. Different Total Camera units can make separation negatives for color reproduction. We are very pleased.

The units incorporate a high quality, large format copy camera; with self- contained lighting, automatic focussing, and wet processing. Reproduction range is 33 to 300%.

VGC Corp is at 5701 NW 94th Ave., Tamarac, FL 33321, 800-998-3400 (I noticed our latest supplies order is to "GraphLine" at the same address and phone number. I don't know if that means they changed their name or GraphLine provides supplies and service (?)).

The only "trick" involved in making high quality photo reproductions is finding the money to pay for one of these. Our newest one was the best part of $12K in 1987!

Ronald M. Anderson
ron-anderson@vnet.ibm.com

We have a FuJix color printer that does transparencies very well. It is not cheap and the transpareancy paper itself is ca. $3.0o a page. The Codonics printers also do a good job. They are ca. $9000. Good luck.

Nina allen
nallen@unity.ncsu.edu

Roy,
You can digitize you EM images, import into PageMaker, export to high quality laser printer (>1200dpi), and print on transparencies directly. The quality is much better than from xerox. Good luck,

Ya Chen
Email:YChen@macc.wisc.edu

Dear Roy,
The main methods of producing high-quality EM viewgraphs that I've come across are:

1. Going to a Copyshop that has a Laser Photocopier, viewgraph ready for photocopying, and having it lasercopied onto transparency. The results are remarkably good in my experience; because the laser-copier prints digitally you can also photocopy a laser-copy with results far better than a photocopy of the original (e.g. for hand-outs from your talk etc.).

2. We obtain very nice results by scanning the original EM negative into a PC using an AGFA Arcus II flatbed scanner; the picture files are then inverted (to get a positive), imported into MS Powerpoint and incorporated in viewgraphs that way. The scanner is used in 'transmission mode' for negatives. If you have a scanner without the transmission feature, scanning a print works almost as well for viewgraphs.

Mark Yeadon
email: yeadon@uimrl7.mrl.uiuc.edu

Dear Roy,
I have had some reasonable results printing digital images onto overhead transparencies on a 600 dpi laser printer. You should scan the images in to at least 2000 by 2000 pixel resolution. The quality depends upon the original digital image and the printer, so the better video printers will do a better job. Also, some copiers have a photo copying option (gray-scale) that will reproduce mid-tones.

However, I don't think an overhead transparency will ever be as good as a slide.

Mary Mager
email: mager@unixg.ubc.ca

oy Hi! If you are making overheads from negatives, Ted Pella has a Dry Silver Processor made by 3M that makes excellent overheads. You expose the negative on the overhead transparency on the enlarger the same as if you were printing the negative. It then takes 6 seconds to run it thru the processor for the finished product. The printer sells for $2150. The overhead transparency film costs about $2 apiece.

Lee Dickey
roy@bayou.uh.edu

Roy: I have used the ILFORD ORTHO film with good results. It processes like paper but requires some trial and error to find the right conditions to get the best projected picture.

I also saw some similar film made by DuPont used in a lab I visited ten years ago. I don't have the references and it may no longer exist. (I would actually be very interested to get the references if the material is still available).

Michel Deschuyteneer
deschuyt@sbbio.be

Hello All,
I guess this might interest fairly many of you. I have used the method which I learned in Japan, Sendai. Juji makes a product called FUJIGRAPH PROJECTION FILM PT-100, which you can get in A4-size.

The film can be used as enlarging paper and the results are very good. They used this film in the MRI in Tohoku University, where Professor Hiraga taught me to use it.

Jouko K. M„ki, Ph.D
jokamaki@utu.fi

You can get some awfully good results from scanning an image at anything over 100dpi and reprinting with a d2t2 (diesub) printer.

We use the Kodak XLS8600, which gives excellent results in B&W or colour.

DON_STEELE@CCKRDC.CA.ALCAN.CA
Don Steele

We use Kodalith to produce photographic quality overheads. I guess other companies manufacture similar products, designed, I believe, for lithographic processes. It's about 1 to 1.5 stops faster than ordinary photographic paper and processes in exactly the same way, apart from drying (like polaroid negatives, you can put it through a dryer but have to be very careful!). With a bit of masking using overheads you can put on micron markers, frames etc. to make it look good. A lot cheaper & quicker than buying a scanner and high resolution laser printer.

Richard Beanland,
richard.beanland@gecm.com

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