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Originally Posted by dpaqu
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http://www.largeformatphotography.in...=1#post1390800
Quote:
Originally Posted by dpaqu
After an interminable hiatus due to a broken leg, I'm back up and running—well, figuratively.
Slowly starting to work again.
Camomile flowers shot with a Rittreck View and a 90mm Super Angulon.
13x18 x-ray film (green sensitive Fuji HR-E).
Rotary development in Ilford MG 1+50 in diy PVC tube for 8min.
Scan from contact print on Ilford MG Warmtone paper at grade 2.
https://farm1.staticflickr.com/788/2...2949a506_b.jpg
I hope the leg heals quickly and completely! The image is simply wonderful, you're getting amazing results with this film. Is this double sided film? Do you strip the backside or leave it on? Can you tell more about the diy development tube; does it allow for free flow of chemicals along the backside of the film as well?
Koraks, thank you.
Yes, it's double sided.
No, I do not strip it.
The PVC tubes are still at the testing stage. I did some research (including this forum) and came up with a number of internal diameters which are supposed to work best for each format.
This particular film was developed in a 3" tube.
The reason why I'm testing this method, is because rotary developing has given me the most consistent and uniform results so far.
I've tried deep tank with Kodak and diy hangers, glass bottomed trays, and a number of Jobo drums, all with different agitation regimes, and rotary is what comes closer to what I'm looking for.
Still, this isn't a perfect method either.
This particular type of film (Fuji HR-E) comes out almost perfect (so far, and under my particular testing conditions), but the Fuji RX-N (blue sensitive, double sided) comes out completely scratched under the same testing conditions.
The Agfa HDR (green sensitive, single sided, AH layer) comes out almost as good as the HR-E, but I have other issues with it (in all probability due to it been expired since 2013, while the Fuji films are fresh.)
Thanks for the update; so your tubes are just that: tubes with two end cos and nothing else? Perhaps the hr-e has a topcoat that prevents from scratching. I know the film I use scratches if you so much as look at it.
I'm a retired X-Ray Engineer. I have worked with film for the last 45 years and all X-Ray film is made for a mechanical film processor or even the old dip-tanks. For 99% of the film the developer is a rapid type at 100-105 degreed F for any where from 25 to 60 seconds in the developer depending on the type of film and the machine rack type ( deep tank or laminar flow tank) All the fixers have a harder in it to prevent scratches as it moves from the fix tank to the wash tank and then the dryer rack.
The rollers today ( pretty much obsolete due to digital imaging having taken over) are made of EDPM rubber compound or a compressed epoxy-paper type to prevent roller marks as the film is transported from one rack to the next.
If your fixer does not have a hardener in it the emulsion swells and will be very soft and easy to scratch until it is dry.
The dryer is hot as in over 125 degrees F and the film is made to take that kind of heat.
Mammography film is very fragile when wet but is extremely sensitive to low light making it ideal for B&W photography. If you have a densitometer, an image with an average density of 1.80 will give you the best tonal range using mammo film.
As for normal X-Ray film a 1.60 will be in the ball park.
X-Ray film is sensitive to the screens Green or Blue that fluoresce depending on the silver coating make up. But the film is very sensitive to any light other than what we see as red. It does see red but at a much slower speed so a red safe light can be used at 6 feet away and no brighter than 5 watts.
I have spent hundreds of hours in an "un-safe light darkroom" where outside light leaked around a seal or an LED of some sort fogged the film or someone putting in a 25 watt bulb or higher burning the safety coating of the safe light fogging all of the film.
Go into your darkroom and turn the lights off. If you see any white light or the overhead lights are florescent there can be an after glow. The film if close enough to the light "leak" will see it and become fogged.
A easy test to do is put your keys or change on a piece of film under your 6 foot away safe light and expose for 60 seconds ( average time to unload a cassette and place the film in a tank or machine) and develop the film If you have a ghost image of your objects, you have an un-safe , safe light of a light leak/ light source fogging the film.
Most X-Ray film is pretty tough stuff as it has to be loaded,unloaded, bent many times as it travels through the film processor machine and then thrown up on a view box or back into a film scanner by Techs that are always in a hurry due to a demanding doctor.
As for quality from batch to batch, lot number to lot number Fuji is hard to beat. Agfa is the worst for QC and was pulled from almost all of my clients due to their problems with QC.
X-Ray film loves the cold,hates the heat. If you order a box of film in the heat of Summer and it sits in a hot delivery truck for hours you will have exposure problems guaranteed.
New film sometimes called "Green film" as in new made last week can be overly sensitive to light and drive you nuts. It needs to outgass and age for a few days once opened to match your other boxes of older film.
I made my living troubleshooting these problems for decades and making sure if you had an X-Ray for a broken bone or breast cancer , you got the best results the Tech could hand to the doctor.
Always test your film before you go on that "picture of a lifetime" shoot. Just because it is new does not mean it is any good. I would send cases and cases back to the maker every week that tested poorly.
White Box or White Label film many times is Agfa film that did not meet specs; so called Factory Seconds. It will work but the next lot number can be way off than what you expected. By law it must be within 3.0 of the last lot number. 3.0! think about that? Yes Virgina, the human eye can see a 3.0 density difference and it is striking.
Hope the info helps. X-Ray film is very interesting to play with in general photography.
Results can be very impressive if you understand it.
And that is a whole other story.
Thanks for the info.
Finally we get an X-Ray Tech on board.
Welcome!
Interesting. From reading that, I've been getting my best results from Agfa rejects.Quote:
Originally Posted by Rapidrob
And what about https://www.zzmedical.com/8x10-in-ca...deo-film.html?
The info provided is useful. We didn't know it was done hot or about hardening fixer.
That said many are getting scratch free results using careful handling.
I slosh 14X36" by hand seesaw in a tray and get great results. 2 clips, 10 minutes and done. Fot that I use Ilford PQ Print develop. It's fast and reusable.
Koraks, yes.Quote:
Originally Posted by koraks
They are plain PVC tubes, manually rolled on a diy roller base.
A couple of notes though:
These tubes don't accept end caps directly. They require a coupling and a screw cap with its own base.
The coupling has a sort of a stopper in its middle which is a tiny bit smaller in diameter compared to the tube itself (can't measure it with my caliper, because it's in the middle of the coupling.)
So, to avoid scratches during loading/unloading, I have only glued the base of the screw cap to the coupling, but not the coupling to the tube.
I load the film directly into the tube. Then I fit the open end of the coupling to the tube.
To deal with leakage from this unglued connection, I first rap around the end of the tube with some thread seal tape. It works fine.
Rereading all the above, I hope that it all makes sense to you and it doesn't sound like gibberish.