X-Ray film weirdness; care to speculate?

Kino

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I expected all the nasties present in the negatives, but not a band of minus density.

Top sheet rated 50 IS0, exposed at 1/2 sec at f11 and bottom exposed at 1/5th sec at f11 (80 ISO?).

D-23 diluted 1:2 for 6:30 in tray with glass sheet in bottom, indicator stop and TF4 fix for 5 minutes.

Two sheets with the same banding across the frame? I think the film is defective...



 

Bronson Dugnutt

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Minus density in the positive implies overexposure in the negative. Perhaps radiation damage or maybe a sticky focal plane shutter.

Potential shutter issues aside, my first thought would be to develop a sheet in full room light and a completely unexposed sheet under safelight. If it is a hard defect affecting the entire batch that would make it quite obvious.

Are both sides of the emulsion effected? When I develop x-ray film in trays I always flip the sheet over so both sides receive sufficient development. You could also try stripping the emulsion from either side of the film. That may provide more information as to the nature/location of the banding if it is present on both sides.
 

Vaughn

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It would show as bands of density on the negative -- some sort of fogging perhaps? Fairly identical fogging...or x-ray exposure, I suppose, if it ever had the opportunity to be zapped.

What type of film? Size? From the title, I though perhaps xray film, but see edge markings on the bottom image.
 
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Kino

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Right about the density; my bad.

This is 8x10 Fuji HR-U Green X-ray film, cut down to Whole Plate, with a 2026 expiry date, so it should be fresh.

Please excuse the color bands in the photo; my light table uses 6500 K florescent tubes that don't play well with digital sensors.

 

ic-racer

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Maybe process a lightly fogged sheet and see.
 

Vaughn

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Pretty bad fogging, but not while in the film holder.

Pick a sheet from each side of the stack of film.
 

Bronson Dugnutt

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The defect extending into the film holder rebate area and being somewhat periodic is leading me to believe this was caused by a pass through some type of x-ray scanning equipment. If unexposed sheets and/or all sheets from different holders & cameras exhibit the issue, then that would be the clear culprit.

Kodak provided a Baggage X-ray Scanning Effects bulletin that indicates the exact nature of the defect will depend on the type of scanning machine used as well as the orientation of the film in relation to the scanning (see the images near the bottom of the linked page). Your examples resembles the 'CTX 5500 end-on exposure' but a direct comparison between roll & sheet film is difficult.

For reference, my stack of HR-U is from an older batch and seems to be OK.

 

koraks

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Looks like something blocking the light path; possibly you mistakenly held the shutter release cable in front of the lens. Doesn't look like a film defect or x-ray damage to me.

@Kino how do you process this film; in trays? Are you using a safelight at any stage of handling this film while it's still sensitive (i.e. before stop bath)? If so, try turning it off and see if the problems persists. The safelight you use for B&W paper may (will) not be safe for x-ray film.
 
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Kino

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Here's the box from my batch. Note that it was originally imported to Australia according to the label. If true, this film has traveled quite a bit and who knows through how many entry ports. I bought mine on Ebay; maybe an argument to only buy from a medical supplier in your country.




That's what I thought it looked like at first, but I didn't use a cable release and I was quite careful to trigger the shutter gently.

Last night, just before I went to bed, I took the camera into a dark room with a flash light, checked the interior for loose items (none) and for light leaks (none).

I used an oversized tray with a sheet of glass in the bottom to process the film and one of those oversized, red globe safe lights (basically a dipped globe bulb) far back in a corner (8 feet at least) away from the film. In fact, it was so dim it was practically useless. The light was largely blocked by my film drying cabinet, which is to the immediate left of the sink and the light was beyond that, shining into the corner.

Some of the random unevenness of the plate density could probably be attributed to this untested light, but that strip is too uniform from sheet to sheet for this to be the issue.

 

koraks

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What kind of light did you use to cut the film to size?
As @Vaughn said, you've got pretty bad fogging all over the place. I'd fix that first before trying to troubleshoot other issues.

Btw, that safelight looks pretty orange. Not sure if that's going to work well with xray film. AFAIK Super HR-U is orthochromatic so any green light will fog it. Typical darkroom safelight filters are not made for handling this material. For me, red LED filtered with additional layers of rubylith worked well enough.
 
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Kino

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Same light to cut the film. I have new bulbs arriving today or tomorrow, depending upon USPS...
 

koraks

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Ok, see what happens. And in first instance I'd suggest processing a sheet from original box all the way to stop/fix in absolute darkness to ascertain that your material is unfogged - which I expect it is, but it tends to be good for peace of mind to establish it beyond a doubt.
 
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Kino

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Well, I pulled a sheet from the middle and the back of the pack and I cannot see the above defect. Either the fogging is limited to a certain number of sheets on one side of the pack or I did something drastically wrong when I pulled the first two sheets.

I could also have leaky film holders; investigating that now. Since I used one, double sided film holder, it might make sense that the leak spans the two chambers on one end. I'll probably load all them with photo paper and hang them outside for a while to see if there are leaks.

I did, however, discover that the small, red AC safe lights sold on Ebay are NOT safe with Fuji HR-U Xray film. I did a 1 through 10 minute wedge with the film on my enlarger baseboard (of course, not turned on), about 5 feet away with the light reflected. There is practically no difference between the steps, but the ruler I laid over one edge was perfectly clear.

I am not saying these don't work for other applications, but be aware of my experience if you are thinking of using them for X-ray film.

https://www.ebay.com/itm/235241444895

Yes, I know of the other filters, but I had these on-hand, so I tried them; no dice. Just add it to the knowledge base...
 

Andrew O'Neill

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In regards to safelights, I've been using my "hanging from the ceiling" safe light, with the yellowy orangey coloured filters, with no issues.
 
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Kino

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And you are using Fuji HR-U; correct?
 

Bronson Dugnutt

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Arrrgghhh.... *shakes fist at safelight*. On the upside, at least the entire package isn't toast.

I've been luckily with regards to my safelight. It was something I already had on hand before I started using film in earnest. It came as a 'freebie' along with a telescope purchase I made some years ago. Red LEDs are a great option for safelights provided you can find the correct type & power. Their emission spectrum is extremely narrow which allows them to be used without any additional filtration. The idea of using any type of incandescent / black-body source, even with filtration, would make me uneasy.

I suppose the one exception to that unease would be the under lens red safety filter that was supplied with my enlarger. It seems to be safe enough when paired with a relatively low wattage incandescent bulb.
 

jonathanchli

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When working with Blue- or Green-sensitive X-ray films (Agfa, Carestream, Fuji or unkonwn house brands) in the laboratory, we use Kodak GBX-2 safelight filter in front of a Kodak bullet lamp fitted with a low wattage incandescent bulb (pointing away from the film). At home, I substitute the low wattage incandescent bulb with a low wattage Red LED.

We also never use/switch on any fluorescent tube, CFL or LED bulb in the darkroom because some of the fluorescent pigment(s) in the tube/bulb can emit a dim afterglow for a while...
 
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