SLIDE COPYING ON A SHOESTRING

By Geoff Ashworth, FRPS 

We often need copies of our favourite transparencies but commercial copies can be unsatisfactory, often with a marked colour bias (usually blue). We can, of course, buy professional copying equipment, but this is expensive and is difficult to justify for occasional use. There is, however, a fairly simple (and cheap!) solution - my own copying set-up involves a once-only outlay on “equipment^TM of about £10, requires no special camera, lens, or film, not even a darkroom, as all I need to do is draw the curtains and set up my projector and screen on the dinning table. 

I need copy slides to send to exhibitions or to use in lectures and as I rarely part with originals, the vast majority of my exhibition acceptances over the past few years have been produced by my simple rear-projection method. I use a normal slide projector and an old Olympus 0M2 camera with either a standard lens or a short zoom, but occasionally with a micro lens if I wish to go in really close to copy a small part of the projected image. The only other item needed is a small rear projection screen, made by fastening some rear projection material on an old picture frame. 

This is the set-up:­

What could be simpler? But let’s go into a little more detail: 

PROJECTOR: Any projector will do, provided it will focus on the screen from a distance of about 3 feet. A zoom lens on the projector does make life easier as it avoids the need to keep moving the projector backwards and forwards to vary the size of the image on the screen. Bear in mind that the smaller the projected image, the sharper it will be, and I am usuallycopying an image not largerthan about 12”x9”. 

CAMERA AND LENS: Any SLR camera with TTL metering can be used. A standard lens usually focuses down to about 1511 so is OK for the size of the image being copied. A short zoom (mine is 37-70) is useful as this helps to line up the image to be photographed without having to move the tripod. A good solid tripod is essential. I use the lens fairly wide open and using the camera meter exposure is usually between ½ a second and 2 seconds, depending upon the brightness of the slide being copied. I will often deliberately underexpose the copy to increase colour saturation. 

FILM: The advantage of this method is that I use my normal daylight film, so I can make copies at anytime without changing the film already in the camera. 

Normally I use Fuji Provia or Ektachrome Elite 100 and both give very satisfactory results. Copying can increase contrast to a greater or lesser degree, but I have not found this to be a problem with these films. I avoid Kodachrome 25 or 64 as I do find them contrasty. 

Filtration: Using daylight film under artificial (projector) light means that blue filtration is required to balance the film/light and here some experimentation may be required to obtain the correct balance because each person’s set-up can be slightly different - the projector, camera, lens and type of film being used. 

It is not too difficult to obtain a perfect balance, though, and I suggest using a Hoya blue 808 filter as a starting point - this particular filter does give me a perfect balance with both the films I use. Once you have found the correct filtration, stick to it and to the same camera, lens and film. I filter the light coming from the projector, by fixing the blue filter to the front of the projector lens using blue tack, as this leaves the camera lens free to take other filtration or attachments if you wish to modify the image whilst copying. If copying a Kodachrome slide, there can be problems in obtaining correct colour balance and I find that some additional magenta filtration helps in this case. 

SCREEN: Here lies the secret of the whole set-up - a small rear projection screen that will give a bright grain-free image with even illumination (no ‘hot spot” in the centre). I have experimented with many different materials for such a screen with varying degrees of success, the “hot spot” usually being the problem. Some retailers advertise so-called Rear Projection Material, often quite expensive, but even this usually suffers from “hot spot” and is not suitable for slide copying. I have, however, at last discovered a particular type of plastic material that is grain free and gives perfectly even illumination without any trace of “hot spot”. Unfortunately it is not available retail as it is made for a different commercial use, and it has to be bought from the manufacturer in a bulk roll with a hefty carriage charge because of weight and packing. I cut up his material into pieces of suitable size and have already supplied it to Clubs and individual photographers who all seem to agree that it is ideal for the purpose. 

MODIFYING YOUR SLIDES: We have been talking about straight copies of slides, but this can be just the start. The method is ideal for producing creative images from your slides whilst copying them. You can experiment by using different pieces of patterned glass -stand them against the screen whilst projecting a suitable slide and whilst looking through the camera viewfinder, move the glass around until that elusive “winner” comes into view. Keep your lens wide open when using this technique to retain the exact image you see when you press the button. You can use various filters and attachments to modify the image, change the colour, or, of course, copy just a small part of your original slide. 

Why not have a go? You already have everything you need apart from the rear projection material and I can supply pieces of this approximately 16” x 14” ready to fasten to your old picture frame. 

The cost - £10 for a piece plus £1 postage and packing; a little expensive but being plastic will last for years with care. My address is: 26. Rydon Acres, Kingsteignton, Newton Abbot, Devon, Q12 3YN. 

(Geoff Ashworth is a member of the Western Counties Photographic Federation and thanks are given to Geoff and, Sir George Pollock, editor of the WCPF, for their kind permission to publish this article).  

CR.C. EDITOR’S COMMENT

I was very interested on reading about Geoff’s offer for his slide-copying, screen material and sent off for a sheet and received a reply in very good time. I haven’t as yet been able to give it a try, as this will have to be a “winter night’s” activity, but I was most impressed with the picture quality on simply holding the ‘sheet’ in front of my projector, it gave an extremely bright, even and fine-grained picture. I plan to try it for both slide and cine copying, but it could be the ideal material for building your own back-projection screen. l”m sure Geoff would be pleased to give you further advice if you need it.