--> Skip to main content

A New Method for Processing X-Ray Film

Anybody shooting large format film today knows that film is extraordinarily expensive. A sheet of 8x10" black & white film will run anywhere from $3 to $10. Those interested in ultra large format photography have come up with various ways of shooting on a budget: paper negatives, lith film, and X-ray film. X-ray film costs anywhere from $.50 to $2/8x10" sheet.

When you first think of X-ray film, you might imagine a film capable of seeing through surfaces. But get your mind out of the gutter! For the conventional photographer, X-ray film has some quirks. But if anything those quirks limit what the film sees, not expands.

X-ray films typically are orthochromatic. Much like films in the really olden days, they are not sensitive to the red spectrum. For your photography, that means a really red rose will look blackish. For portraiture, that means that freckles and zits will look darker than they do, so keep that in mind.

A big plus to orthochromatic films is that they can be handled and developed under red lights. So you can develop by inspection - actually watching the latent image materialize much like when you print conventionally.

Another quirk to X-ray film that presents the biggest challenge to conventional photography is that most films are coated on both sides! What does that mean to you, the budget large format photographer? Several things....

First off do you know what turns your prewash to blue, green, or black? When you pour clear tap water in to your film drum and it comes out colored, that is a dye adhered to the back of conventional films called an anti-halation layer. That prevents light that hits the film from bouncing around off the back of the film layer causing blooming highlights. If conventional film has an anti-halation layer, then you could call x-ray film's secondary layer a "pro-halation" layer. Instead of discouraging those hightlight blooms, x-ray film encourages that effect. Never fear, it can add unique feature if employed correctly.

Another related effect is that photos are going to appear less sharp. There are two identical images with a several micron thick piece of plastic separating them. So in addition to those blooming highlights, there will be a slight overall glow to any image.

But most importantly, the double sided emulsion makes processing difficult. Processing in a conventional drum blocks the chemistry from completely penetrating the back emulsion, which with normal film would just be the plastic backing. That effectively ruins your image, since the back emulsion is very unevenly processed. Some photographers deal with this problem by scratching off the back emulsion.

Other photographers have dealt with this by careful tray processing or other techniques. I've heard of people using ziplock bags as an example. But I've come up with what I think is an easier solution. I just lined the conventional 8x10" tray with plastic cling wrap. It seems to have minimized scratching problems and is very easy and cheap to apply.

Give it a try!

(sample photos to follow)


Popular posts from this blog

Linhof Serial Year List - Salomon Says

Recently I've acquired a few Linhof cameras. I got a 5x7 view camera from Oakland Museum's White Elephant Sale. Later I stumbled upon a Color Kardan 90 Jahre Jubalaeum edition on Craigslist. And more recently, I found a "baby Technika" 2x3 (6x9) at Oakland's East Bay Depot for Creative Re-use. Not knowing much about Linhof large format cameras, I tried getting more info online, and came across a strange thread on the Large Format Photography Forum . Basically on this thread various Linhof owners ask a guy named Bob Salomon what year their Linhof was made. And the thread is over 100 pages long! Sifting through that thread is mindnumbing. Why Bob doesn't just publish the list of serial numbers is beyond me. Maybe it's just nice to feel needed. So I started compiling a spreadsheet of the serial numbers and the answer Bob gives. If you don't feel like spending a couple days reading this thread to get a hint as to the age of your Lin

Lossy DNG File Sizes by ISO.

Fairly recently I discovered the magic of lossy DNG's. My stock photo library is ever growing. Though JPG's might really be enough for my archive, I've been keeping my raw files. RAW files take up lots of space. And RAW files can't typically keep user generated EXIF data in the file. RAW files keep their keywords and other metadata in a sidecar, that is if you regularly save the EXIF data to file. So recently I've been converting all my RAW files to lossy DNG's. After testing the highest ISO setting on the new-to-me A7R IV, I converted the files to lossy DNG's only to find a surprise. The very high ISO lossy DNG's were much larger than the original Sony RAW files! Lossy ARW vs Lossy DNG full image sample So I thought it would be a good test to shoot from the lowest to highest ISO, convert to lossy DNG and see where the file size savings invert. Here's the data as seen in the above screen shot: ISO Lossy Sony ARW Raw file size (MB) Lossy DNG file siz

From the Archive: Obsolete Film Data Sheet Scans - ORWO Information

Here's a sheet I got from writing ORWO Technischer Kundendienst back in the 1980's. It lists development times for all the ORWO Black and White films sold for export at the time (NP15, NP22, NP 27) combined with western developers Microphen, Atomal, Rodinal, Refinal, D-76, & ID-11. A little bit of ORWO history- Germany's big photo film/paper manufacturer up until Germany's losing WWII was AGFA (short for  A ktien G esellschaft F ür A nilinfabrikation - or corporation for some sort of plastic manufacture.) Germany was occupied by the winning powers USSR/USA/GB/FR and the rift between the USSR led to some complications for industries. Depending on your view of history the US and western allies were much friendlier to the land they occupied (remember the USSR lost many millions of their citizens to the NAZIs which made them much less tolerant.) In any case, some factories in the east moved to the west with many key employees. Most photo enthusiasts know of the t