Re: X-ray Film example and comparison.
It's sharp enough for contact printing. Yes, it's due to emulsion on both sides. My carbon prints look very nice. I've never tried to enlarge with it and I don't entend to.
I don't understand how a formalin pre-soak would work as a hardener. Wouldn't the film have to be dried first so that the formalin can "harden" the emulsion?
Also, placing a sheet of glass in the developer tray is a good idea, but my trays are flat bottomed and smooth, so not necessary. The key is to use minimal, gentle agitation. I tried the ziplock bag method, and it worked very well.
Re: X-ray Film example and comparison.
Quote:
Originally Posted by
Andrew O'Neill
It's sharp enough for contact printing. Yes, it's due to emulsion on both sides. My carbon prints look very nice. I've never tried to enlarge with it and I don't entend to.
I don't understand how a formalin pre-soak would work as a hardener. Wouldn't the film have to be dried first so that the formalin can "harden" the emulsion?
Also, placing a sheet of glass in the developer tray is a good idea, but my trays are flat bottomed and smooth, so not necessary. The key is to use minimal, gentle agitation. I tried the ziplock bag method, and it worked very well.
I was thinking that if you could run the film in the formalin pre-soak before processing it would make it easier to handle the film without scratches. But it might not work as the formalin could render the emulsion useless so I just wondering if anyone had actually tried a pre-soak. Maybe this has already been answered but the thread is very long.
Sandy
Re: X-ray Film example and comparison.
As I understand it, the formalin presoak is primarily for "tropical" or high temperature development, and prevents the emulsion from swelling. I have no idea if this would help with xray film.
Regarding the (lack of) sharpness, only on rare occasions do I see the sort of bleeding highlights I would expect from the second emulsion causing halation. Rather the emulsion (for lack of a better adjective) seems thin--lacking body and depth--which often means that the "razor" sharp edges are absent. Of course, this is largely irrelevant with most alt processes. I do notice however that when I use studio strobes or in contrasty and directional outdoor light, the film is notably sharper than when I with diffuse light.
Re: X-ray Film example and comparison.
And I imagine the type of light used in the exposure system would have an effect on sharpness. A point source system like halogen perhaps would be slighty sharper than a a bank of uv flourescent tubes.
Re: X-ray Film example and comparison.
Today I developed a sheet of x-ray film in a zip lock bag but this time I inflated the bag with air after I poured in 2 litres of developer. It was then placed in an 11x14, flat-bottomed tray. Why did I inflate the bag? This way the top side of the bag won't touch the film and makes agitation a lot easier. Because I blew in air from my mouth, the temperature of developer after development rose from 20C to 21C. I now know that I am full of hot air...
A bit of water in the same tray set to 20C should control the temperature.
Film is scratch free.
Sandy, if you read this I'll bet you could develop a 20x24 sheet in a black plastic 20x24 photo paper bag.
Re: X-ray Film example and comparison.
Andrew
What developer and why so much?
Please and thankyou
And Jason , don't forget the stripping of one emulsion side technique- that should tell us if it's the diffusion due to the base or the emulsion- my WAG is that a slow ortho emulsion should/would/could be pretty sharp on its own.
But NO GUESSING
Re: X-ray Film example and comparison.
Quote:
Originally Posted by
EdWorkman
...And Jason , don't forget the stripping of one emulsion side technique- that should tell us if it's the diffusion due to the base or the emulsion- ...
Somewhere earlier on this thread someone reported stripping one side of the emulsion, and as I recall, the difference in sharpness did not appear significant.
Re: X-ray Film example and comparison.
I tried a goofy thing a while back just for fun. I added 4 grams of glycin to D76 and it knocks the contrast on identical sheets back about 1 stop.. It's easy to do and I just ordered some 11x14 x-ray film to play with so can contribute more once I have exposed and developed some...Evan Clarke
Re: X-ray Film example and comparison.
I just finished developing a sheet of Blue in a ziplock bag. Pyrocat HD in glycol .75-.75-100 oz. 15 min 68 degress agitate by flipping the bag 3 cyles , 15 sec per minute. I poured 16 oz in the bag and inserted the film. This amount let the film sit just above the level of liquid [ 10 '' horizontal, 8'' vert] until turned it flat.
NO SCRATCHES as reported,
but
a strip of high density along one edge- could possibly be not procedure related, but that edge was nearest the bottom of the bag, hmmmm.
Bad news- I did a presoak in a different bag and transferred the wet neg to the develope bag, leving my prints in the middle of the top long edge of the neg, sigh.
Neg try will be presoak in the bag and pour the developer onto the film. As pyro is so dilute I fear/expect Mackie lines, i hope the presoak will solve that. But I have to think on this more before I jump in again. The neg is still wet, so no conclusions about how it will print on VC- I think I might increase develope time a bit. As I struggled to get the neg into the bag, I pulled it out and trayed it in TF-4 fixer.
If I just had several more thumbs.
Re: X-ray Film example and comparison.
I decided to check out this films response to long exposures. Someone earlier said that this film is not affected by reciprocity effect. Not true.
Please see attachment of curves for 1, 10, and 100 second curves. The 1/8s curve is my reference curve. You can see that there is considerable speed loss even at 1 second.
I also carried out a tonal/colour response comparison with conventional b/w film. I'll upload later.
