Hi all,
I'm thinking of getting two betterscanning 8x10 ANR glasses for sandwich 8x10 portra instead of taping them to one ANR glass. (and four coins at each corners for the height.)
I really don't enjoy putting tapes on negs and removing them.
Did anyone try that? Would it cause any loss of image detail?
Thanks!
It certainly would. ANR glass is just very fine ground glass.Originally Posted by rustyair
Would you loose detail if you looked at a negative through a ground glass?
You could try putting a good piece of clear glass on the emulsion (down) side of the negative.
That side is not normally prone to Newton's rings.
Of course the negative must still be at the proper height for the scanner to focus on it.
So you would need to rig some kind of support between the clear glass and the
scanner glass, then let the negative and ANR glass just sit on top of it.
- Leigh
If you believe you can, or you believe you can't... you're right.
hehe.. just was thinking about it last night, while scanning batch of 120 film and dealing with whole taping .. ugh.
going to try it today, seeing that i got both 4x5 and 8x10 mounting glasses...
The glass that contacts the smoother, non emulsion side would likely show newton rings and depending on the film emulsion you might get rings on the emulsion side. Then you certainly have a partial air interface on both sides leading to interface reflections and a loss of contrast compared to index matched surfaces using wet mounting. Probably also some loss in resolution as Leigh explains but that may be slight. I've not tried the sandwich approach with LF film. If you're using an Epson V 750 you have a couple of mm depth of focus from that primitive lens before you'll see a visible loss of resolution so if you can arrange an all non glass mounting you will get the highest contrast and best resolution.
You can minimize or eliminate the newton ring problem when using normal smooth glass by either of two methods. Bake the film and the glass ahead of time (a low temperature of course) or put the film and glass in a dessicator box to dry the surfaces. Either of these techniques are only a partial cure in that you must work quickly to get the glass sandwich on the scanner. Just a monolayer of water vapor will deposit in seconds depending on the RH at the scanner and the temperature of the glass sandwich.
I have used the clear glass sandwich as you describe for making scans of 35mm film on a Nikon coolscan 5000 when I can tolerate a bit of loss in contrast. But I do that during the heat of the summer in Austin when the relative humidity is < 20% and the film has been heated slightly on the light table. Rarely do I have newton ring problems.
Actually I've found the effects of all these variables are small and sometimes difficult to quantify. Coarse anti newton glass can significantly degrade image quality so I don't like to use that.
Nate Potter, Austin TX.
Not the ANR I know.
OP - You can use only one ANR glass - with the dull side touching the non-emulsion side.
Clear glass facing the scanning lens with film emulsion right behind has no practical visible image degradation as long as it is good clean piece of glass. For the base side of film use ANR glass.
I've never tried it, but placing ANR glass on the emulsion side, where you want the scanner would be focused, would also sharply image the slight texture of the ANR glass. I would expect it to look fuzzier than using plain glass there.
-Chris
On the V700/750 you cannot use the High Resolution lens with 8x10 negatives/transparencies, you can only use the 'wide transparency' setting which requires you to place the negative directly on the platen of the scanner. I use a piece of A4 sized 2mm Anti-Newton glass on top of the negative to hold it completely flat against the platen emulsion side down.
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