XRAY Film As A Copy Film?

[Andrew O'Neill]

 

[FotoD]

Interesting video as always, Andy!

I've used Ilford Ortho (120) for the interpositive step. And then enlarged that to X-ray film. That gave somewhat better sharpness IMO. Still softer than an in-camera negative of course.

 

[koraks]

Cool! I used it in that application here as well: https://www.photrio.com/forum/threa...be-scan-one-negative-2025.215648/post-2937385

In my case the sharpness was not an issue because I used single-sided x-ray film, which sadly is no longer readily available.

PS: yes, I can see the difference in the video, but whether it's meaningful is another matter.

 

[Andrew O'Neill]

Cool! I used it in that application here as well: https://www.photrio.com/forum/threa...be-scan-one-negative-2025.215648/post-2937385

In my case the sharpness was not an issue because I used single-sided x-ray film, which sadly is no longer readily available.

PS: yes, I can see the difference in the video, but whether it's meaningful is another matter.

I do have a box of Kodak Ektascan single-sided to try it out with. I know what will happen, though. I will love it as a copy film, run out, and unable to find more...

 

[Kino]

Andrew, you mention stripping-off one side of the emulsion in the video.

Just how fraught with danger to the other side of the emulsion is this process?

 

[pentaxuser]

I liked the music so much I had difficulty concentrating on your presentation "It's a quarter to three and there's no-one in the bar except you and me" kind of music where the P.I. describes his story involving "dolls", booze, Jimmy Mulloy, detective first class, who is his "police nemesis" etc. It's all in B&W of course and constant night

pentaxuser

 

[Andrew O'Neill]

Andrew, you mention stripping-off one side of the emulsion in the video.

Just how fraught with danger to the other side of the emulsion is this process?

I tested it quite a bit. As long as the film is duct taped down to glass, the side facing the glass is safe (that's the side we want to keep). I never had an issue with bleed over. Very little ammonia is required to remove the emulsion.

 

[Kino]

I tested it quite a bit. As long as the film is duct taped down to glass, the side facing the glass is safe. I never had an issue with bleed over. Very little ammonia is required to remove the emulsion.

Straight or diluted? Thanks for the clarification!

 

[Andrew O'Neill]

Straight or diluted? Thanks for the clarification!

Straight. I never did try it diluted... Probably would work, but maybe take a bit longer.

 

[cowanw]

If the difference in sharpness in the first enlargement is due to a thickness of film, I would have thought that the Depth of Field (which can be quite deep) of the 35mm enlarging lens at a smaller f-stop would be way larger than the thickness of an x-ray film. Maybe you could test focus on the x-ray film and then focus on the easel and split the difference. I think the difference would be tiny, Perhaps a Gelatine print of the 35mm negative would be just as soft anyway?
Is your easel white and is there reflected light coming from underneath?
Your premise seems off to me. (but I have never done this)

 

[FotoD]

It's not just the depth of field. It's also the geometry of projecting an image to different distances. They will not be the same size, and therefore less sharp when printed together.

 

[koraks]

There's also scatter in the top emulsion layer. DoF doesn't solve this, trust me. The backside image on double sided x-ray film is just fuzzy, there's no way around that.

 

[Andrew O'Neill]

If the difference in sharpness in the first enlargement is due to a thickness of film, I would have thought that the Depth of Field (which can be quite deep) of the 35mm enlarging lens at a smaller f-stop would be way larger than the thickness of an x-ray film. Maybe you could test focus on the x-ray film and then focus on the easel and split the difference. I think the difference would be tiny, Perhaps a Gelatine print of the 35mm negative would be just as soft anyway?
Is your easel white and is there reflected light coming from underneath?
Your premise seems off to me. (but I have never done this)

People who have used most xray films would get this. It's got nothing to do with DOF. This is double-sided film. It has emulsion on both sides. The side facing the lens during the exposure is sharp. The emulsion on the other side is unsharp. There is no way around this unless you strip the unsharp side after processing... But this technique literally cuts the density range in half. I tested this 'til the cows came home. An easier way around this issue, is to use single-sided xray...

 

[koraks]

So...was the milking alright?

Sorry, couldn't resist - LOL!

 

[Andrew O'Neill]

 

[MCB18]

I have a bunch of x-ray film coming in at some point, I’m very curious to see if it is double sided, or single sided. The data sheet seems to indicate that it is double-sided, but I have also heard folks say that it is only single sided.

 

[koraks]

Virtually all of it is double-sided. The main exception is the film specifically intended for mammography. It's rare and generally significantly more expensive.

 

[MCB18]

Virtually all of it is double-sided. The main exception is the film specifically intended for mammography. It's rare and generally significantly more expensive.

It’s NDT film, not medical film. Seems like that is a more mixed bag. I know that both single- and double-sided NDT films exist. Just not sure exactly what this stuff is.

 

[cowanw]

It's not just the depth of field. It's also the geometry of projecting an image to different distances. They will not be the same size, and therefore less sharp when printed together.

If this were so then the effect would be dof related for sure ? for an extra projected distance of .25mm

 

[cowanw]

There's also scatter in the top emulsion layer. DoF doesn't solve this, trust me. The backside image on double sided x-ray film is just fuzzy, there's no way around that.

Scatter sounds better but if this were so then contact prints on regular film should always be printed emulsion to emulsion and thus backward? Maybe that is so? but not great for portraits or other right left sensitive images.
Still if its so then it is so! I would still like to see a same size gelatine print of the 35mm negative.
Xrays always seemed tack sharp to me, although it is true Mammograms used single side xray film

 

[Kino]

People who have used most xray films would get this. It's got nothing to do with DOF. This is double-sided film. It has emulsion on both sides. The side facing the lens during the exposure is sharp. The emulsion on the other side is unsharp. There is no way around this unless you strip the unsharp side after processing... But this technique literally cuts the density range in half. I tested this 'til the cows came home. An easier way around this issue, is to use single-sided xray...

I have to wonder if you could intentionally over expose the film by a stop (or more) and then strip off the back emulsion; did you try this?

Of course, you would have to flip the negative as you did in the experiment to keep the front emulsion in contact with the dupe negative. Might even have repeat the process on the resulting dupe negative.

Just wool gathering here...

 

[AnselMortensen]

<Disclaimer On>
Sometimes...
<Disclaimer Off>

Most of the time, single-sided film has a code notch.
No need for a notch with double-sided.

 

[MCB18]

you know, @Andrew O'Neill i should really send you some of this 2422 stuff I have, bet you would have fun with it.

 

[cliveh]

I would have thought that Xray film is perfectly good as a copy film.

 

[koraks]

contact prints on regular film should always be printed emulsion to emulsion and thus backward

Contact prints are indeed emulsion to emulsion and that's how they end up in the correct orientation.