1 Attachment(s)
Re: Use of X-ray film: technical discussion with example images
Quote:
Originally Posted by
seezee
I'm not sure what's causing your problems with the cutter. There will always be a small 'waste' cut-off, due to the difference between nominal and actual dimensions for 4×5, but my Dahle cutter handles that with aplomb. Did you mark the cutter with e.g., Dyno tape, so you can accurately set the guide with reliable repeatability? Are you trying to cut more than 1 or 2 sheets at a time?
As to the scanner, I just bought a scanner after having paid for the cost of an Epson v850 in $5 + tax chunks, that being the price of a 2400 dpi scan with dust removal & output to TIFF at my local lab. So I feel your pain.
These local guys don't even remove the dust. The 4$ is for a low resolution scan.
How exactly are you cutting? Please, could you explain your process?
This is what's happening to me:Attachment 155729
I end up with that 2/16' lip at the edge, and it's just too slight for the Dahle Vantage guillotine blade to snip. I've tried pushing the blade slow and pushing it fast. Either way, it refuses to cut the paper and simply bends it instead.
Re: Use of X-ray film: technical discussion with example images
Quote:
Originally Posted by
senderoaburrido
These local guys don't even remove the dust. The 4$ is for a low resolution scan.
How exactly are you cutting? Please, could you explain your process?
This is what's happening to me:
Attachment 155729
I end up with that 2/16' lip at the edge, and it's just too slight for the Dahle Vantage guillotine blade to snip. I've tried pushing the blade slow and pushing it fast. Either way, it refuses to cut the paper and simply bends it instead.
Exactly. 4×5 is ~1/16″ smaller in each dimension than nominal. You should wind up with a ⅛″ waste piece, which the Dahl should be more than capable of handling.* Here's how I do it:
- Cut 1 sheet at a time, beginning by making a 4-15/16″ wide piece and a 5-1/16″ wide piece for each sheet. The 5-1/16″ is the one that falls off the cutter bed.
- Set the 4-15/16″ pieces aside. Trim ⅛″ from each of the wider pieces.
- Reset the guide. Cut each piece so you get a 3-15/16″ piece and a 4-1/16″ piece.
- Set aside the narrower pieces and trim ⅛″ from each of the wider ones.
I always place the round corner against the fixed top guide and the adjustable guide. If in doubt, hold the film in place with your (clean) hand — although, in my experience, the clamp does just fine. By the way, if you load the film holders with the round corner in the same position that you would put the notches on conventional film, you'll alway know which side was facing the camera. If you're using Ektascan this doesn't matter, but it's useful on the double-emulsion stuff.
I do not find that the speed at which I make the cut has any affect, good or ill.
*Is it possible your cutter is defective?
Re: Use of X-ray film: technical discussion with example images
Is your cutter old? Mine does those cuts easily one at time. I set up stops and cut 4 sheets into 16 all the time.
I pull the knife towards the counter edge slightly.
I use a piece of 'real' as the pattern and use it to set dimensions.
Quote:
Originally Posted by
senderoaburrido
These local guys don't even remove the dust. The 4$ is for a low resolution scan.
How exactly are you cutting? Please, could you explain your process?
This is what's happening to me:
Attachment 155729
I end up with that 2/16' lip at the edge, and it's just too slight for the Dahle Vantage guillotine blade to snip. I've tried pushing the blade slow and pushing it fast. Either way, it refuses to cut the paper and simply bends it instead.
Re: Use of X-ray film: technical discussion with example images
For cutting film with a guillotine cutter that I borrowed from church from time to time I used an oops sheet of film to get close. Then, I made a corrugated cardboard template very slightly over sized compared to commercial film because it fit my holders with less slop. Then, I used some blocks of maple with sharp (not rounded) corners to create stops on the guillotine cutter. These I held in place with a small C clamp. The guillotine cutter works better if I cut one sheet at a time and (and this is key with the one I used) you have to press the blade toward the stationary part of the cutter, at least a little. For 5x7 I cut off an almost 1" strip 10" long. I do a bunch of these and then put everything away light safe. Then I re-set the stop so I get the 5" dimension. Yes, you do end up with slivers of film. 4x5 is similar but easier to mess up because the dimensions are more similar. I'd do a bunch of one, reset, then do a bunch of the others. Before I get too far I like to check how they fit in the holders just to make sure I've not made a dumb mistake like making the film 4x4 or 5x5. Don't ask how I know I need to do this...
My local photo store has a rotatrim. That costs a LOT more but cuts beautifully. Maybe some day. Meanwhile, I scored a free guillotine cutter at a yard sale this summer, but haven't tried using it yet. The bigger one from church could break down 14x17--->whole plate, but that is also a future if ever need...
why goto all the expense and hassle of scanning when you can make contact prints? Just saying...
Back to film cutting: from what I've been told, in the bad old days of glass backed negatives being common, the plates actually were 8x10." Then, people started coating emulsions onto (?cellulose nitrate? cellulose acetate?) some kind of plastic. The plastic film was MUCH thinner than the glass plates of old and flopped around too much to use them in glass plate holders. So, someone had the bright idea of making an insert into the glass plate holders that would allow you to use your existing film holders with the new film. This insert was made out of sheet metal. The sheet metal adapter holder has some size to it, so 8x10 exactly films did not fit, they had to be an 1/8 or 3/32 or some such smaller side to side and top to bottom. Thus, 8x10 film is a little smaller. When we go to cutting 4x5 or 5x7 from 8x10 those losses get doubled in both dimensions in 4x5 and in one dimension in 5x7 because they did the same thing (I think) with 4x5 and 5x7 holders. In the end, the slightly smaller than the nominal dimensions became the standard even for purpose made film only (glass plates would not fit) film holders. I have had the blessing to end up with 5 8x10 holders that have the metal inserts or could be used with glass plates. Since I want to make my own films some day, I'm really glad to have them even if I have to have a non-standard set up for the camera back.
If that's not weird enough I have a 1/2 plate camera that came with three holders all of which had adapter inserts for 4x5. These are much more crude than the nice ones sold by E.Kodak, but they work! (after a fashion).
Re: Use of X-ray film: technical discussion with example images
Quote:
Originally Posted by
seezee
Exactly. 4×5 is ~1/16″ smaller in each dimension than nominal. You should wind up with a ⅛″ waste piece, which the Dahl
should be more than capable of handling.* Here's how I do it:
- Cut 1 sheet at a time, beginning by making a 4-15/16″ wide piece and a 5-1/16″ wide piece for each sheet. The 5-1/16″ is the one that falls off the cutter bed.
- Set the 4-15/16″ pieces aside. Trim ⅛″ from each of the wider pieces.
- Reset the guide. Cut each piece so you get a 3-15/16″ piece and a 4-1/16″ piece.
- Set aside the narrower pieces and trim ⅛″ from each of the wider ones.
I always place the round corner against the fixed top guide and the adjustable guide. If in doubt, hold the film in place with your (clean) hand — although, in my experience, the clamp does just fine. By the way, if you load the film holders with the round corner in the same position that you would put the notches on conventional film, you'll alway know which side was facing the camera. If you're using Ektascan this doesn't matter, but it's useful on the double-emulsion stuff.
I do not find that the speed at which I make the cut has any affect, good or ill.
*Is it possible your cutter is defective?
Quote:
Originally Posted by
Randy Moe
Is your cutter old? Mine does those cuts easily one at time. I set up stops and cut 4 sheets into 16 all the time.
I pull the knife towards the counter edge slightly.
I use a piece of 'real' as the pattern and use it to set dimensions.
I hope it is not defective. It isn't old, though. Bought it ~2 months ago at a Canadian office supply company.
I'll take the advice offered here and cut much closer to the edge of the board, in case the spring tension is keeping it an integral millimetre or two away.
Re: Use of X-ray film: technical discussion with example images
"why goto all the expense and hassle of scanning when you can make contact prints? Just saying..."
Agreed!
Re: Use of X-ray film: technical discussion with example images
For cutting down to 4x5, I drilled holes in the wooden bed of my guillotine, into which I place finishing nails. Make the 5" cut, move the nail over to the 4" hole, make 4 more cuts... Easy, even in the dark. I then snip a corner with scissors if needed to serve as notches.
Re: Use of X-ray film: technical discussion with example images
X-ray is fine in dim red light. So notches are t needed even with single sided stuff. It's really obvious. The non black side goes toward the lens. With double sided it doesn't matter. I bought a nifty antique ticket punch before I figured this out. I should re-sell it.
Re: Use of X-ray film: technical discussion with example images
I tried again last night. Worked a lot more carefully. Pushed the blade a little closer to the edge, which seemed to make perfect cuts and curved cuts alternatingly. Ended up with about 1/2 good negatives, and another half that needed extra trimming with scissors. Much better rate of success, much firmer fit in the holders. Thanks guys! I'll have to pay closer attention next time to improve my technique.
Re: Use of X-ray film: technical discussion with example images