Re: Use of X-ray film: technical discussion with example images
This thread is the longest thread in internet history and I am lost for time to glean it for a few answers. I have a 7 or 8 year old box of Fuji HRT Green sensitive X ray fim and want to get busy on some basic experimentation. I know the perils of old flim, but for the moment I will put that aside. I will soon buy a fresh box if need be. I've affixed a Hoya K2 yellow filter to my lens. I need an ballpark ASA rating to start with filter factor already figured in, as the filter will remain there permanently, and a basic starting development time, temperature, and dilution with Adox Rodinal. Tray development. This is 8x10 format. Thank you.
Re: Use of X-ray film: technical discussion with example images
EI 50 6 minutes at 68F 1:100 Rodinal
Re: Use of X-ray film: technical discussion with example images
Thank you. I will start with that. I assume the EI 50 already takes into account the filter factor. I appreciate it.
Re: Use of X-ray film: technical discussion with example images
No
But time of day, month etc
Quote:
Originally Posted by
HT Finley
Thank you. I will start with that. I assume the EI 50 already takes into account the filter factor. I appreciate it.
Re: Use of X-ray film: technical discussion with example images
Here is what I use:
D23 1+2 (Mixed from powder stock chems) 68 deg F
7 min 30 sec normal, for N+1 underexpose 1 stop, develop for 8 minutes
Open tray with plexiglass with smoothed edges in tray bottom, continuous but gentle tray agitation first 1 min 30sec. Thereafter: rock tray slightly 3 times once per minute
Be very wary of safelights, I have one specifically made for X ray film and still have to keep it over 4 feet away and pointed away from the area. I cover the tray whenever possible, and even have to be aware of illumination for the sides
Limited experience with yellow filter, not found a need to change exposure
Re: Use of X-ray film: technical discussion with example images
Forgot to mention, I have had good results from Rodinal as well, I just don't have any and use D23 chem for other things anyway so have it on hand
Re: Use of X-ray film: technical discussion with example images
Quote:
Originally Posted by
Tin Can
No
But time of day, month etc
This, but experiment.
Re: Use of X-ray film: technical discussion with example images
X-Ray people please see TIN Type Zebras above as he has posted charts like of olde
Here
https://www.largeformatphotography.i...Zebra-Tin-Type
Re: Use of X-ray film: technical discussion with example images
I thought I'd report back with preliminary results from today, based on just 2 sheets of film. This is not conclusive, obviously. I was an on-and-off stormy day. Nice puffy clouds and blue sky alternating to storm overcast and rain, back and forth all day. I wanted some blue sky and puffy summer clouds, so I had to jump in from minute to minute. This is Fuji HRT, 8 years old, with a Hoya K2 yellow filter permanently fastened to the rear element of my Bausch and Lomb 12 inch lens in a Betax #4 shutter. First sheet exposed at ASA 25 and developed 5 minutes, 75 degrees in Rodinal 3ml to 10 ounce water. Results: printable, but not perfect. The second ASA 12 same developer and dilution 4 minutes, 75F. On the second, the film showed more printable sky, but a bit lacking in the shadows. More tests are needed. At this time, I believe ASA 12 and 4 1/2 minutes 75F looks like a good place. I was particularly pleased overall. I don't feel so constrained by the constant fight to win over the well-known high contrast battle in using X ray film.
Re: Use of X-ray film: technical discussion with example images
The x-ray films are orthochromatic, some say just close to that. In other words reds do not record, and it is most sensitive to blue. In early morning, near sunset, or on cloudy days additional exposure is required for good negatives. Although some claim to have them, there are NO charts which can be depended upon for accuracy in these conditions. Experience with particular film, developer and methods is required.
Until you are more familiar with the film you need to photograph with it between 2 hours after sunrise until 2 hours prior to sunset. These times are approximate only. After some experience during the middle of the day and with your developer and particular method of development you will be able to nail down this part of the process. Then you can begin to experiment with increased exposure during low light parts pf the day.
Only you can determine this for you. What I do and what others do may be a guide, but that's all, Experimentation is the answer.
