Anti Newton Glass

[dbla]

Is it possible to make your own piece of Anti Newton glass? I've heard it's as simple as making ground glass, but I wasn't sure if there's a specific process to it. If it's not possible, where's the best place to purchase it?

Secondly on a Epson 4990 do I need to use a piece of 1mm clear glass underneath the negatives and then AN glass sandwiched on top? I'm a little fuzzy on the process.

-a

[Gem Singer]

Anti-Newton glass can be purchased at: www.fpointinc.com

Click on Anti-Newton Ring Glass, scroll down, and read the recommendations and instructions for use.

For 120 and 4x5 negatives, the 4990's film holders can be used with no Anti-Newton glass.

For 5x7 and 8x10 negatives, use one piece of 2mm AN glass to hold the negative flat on the scanner glass. Emulsion side down.

Etched side of the AN glass against the smooth shiny base side of the film.

[Walter Calahan]

Your time is more valuable making photos. Buy an anti-Newton Ring glass.

[Peter De Smidt]

For some application, anti-glare picture framing glass (also called "glazing") can be used. It's inexpensive, and it's probably available locally. This glass has a light texture on one side. There is also one textured on both sides, which you don't want to get. The texture on the anti-glare glass is a little coarser than on AN glass, and that texture may show up in a scan. The only way to tell is to test it.

[domaz]

I don't think you can make it as easily as a ground glass. ANR glass has to be really fine grained or else it would show up in the scan right?

[Gem Singer]

Anti Newton glass goes between the scanner light and the negative not between the scanner sensor and the negative.

It's like the diffusion glass in an enlarger. Does not show up in the scan.

[Peter De Smidt]

Anti Newton glass goes between the scanner light and the negative not between the scanner sensor and the negative.


Some current films, for example, have very shiny emulsion sides as well as base sides. As a result, Newton's Rings can occur between the emulsion and a piece of glass. To avoid this, some people, such as (I believe) Howard Bond, use AN glass above and bellow the negative in their enlargers. Moreover on my Screen Cezanne scanner, the clam-shell holders have a very fine AN texture on both the top and bottom pieces of acrylic. Convinced that this would negatively impact sharpness, I built a carrier using clear optical glass. I wet-mounted the film to the optical glass and compared scans with ones made with the clam-shell holders. Even at 6000 dpi I couldn't see any difference in file detail. But Gem is right: The standard practice is to have the AN glass between the film base and the light source.

[domaz]

My Minolta Scan Multi's film holder does use ANR glass on both sides of the holder as well. It's a very sharp scanner for it's age- it's usually a teeny bit sharper than the Epson 4990.

[John Kasaian]

If you don't know if a piece of glass is anti-Newton or not, try putting a fig newton on it. If it resists, its anti-Newton :D

[Lachlan 717]

How necessary is ANR glass for sheet film?

I use it with a Betterscan 6x17cm carrier, where I helps to flatten out the roll film, but don't with 4x5.

As I'm thinking about making a 7x17" carrier for my V700, will ANR glass be of any use?

I was thinking that taping the neg to the glass might help to prevent sagging in the middle of the film, but cannot work out how to accurately do this so that the film is parallel to the carrier's edge.

[dbla]

Let me ask another question then, with my 4990 I run into this RED hazing when I am scanning my negatives. It's very difficult to clone out and appears on every negative that I scan... I can't figure out what I need to clean in order to not get it anymore... I've cleaned the scanner glass, cleaned the negatives... etc etc... any advice?

[Peter De Smidt]

Well, if it's on every negative you scan, then it's probably not from negative processing, although you should use a loupe on one just to be sure.

Is the transparency light source clean? Does the inside of the glass look clean? It could also be dust on the lens or sensor. With some careful looking, you can find info on how to clean inside the glass.

[dbla]

There is a "haze" on the inside of the glass... Think that might be it? I've seen the directions to dissect the scanner and clean it, just a little frightened too.

[dbla]

p.s. ICE seems to take it out, with some difficulty (or 30min scan times), but it's not an ideal solution.

[Peter De Smidt]

If it's an even haze, then while it might lead to a loss of overall contrast, I doubt it would cause the spots in question. Make absolutely sure it's not from marks on your negatives. It's possible that your camera lens is dirty.

[venchka]

If the spots are in the same place on all negatives, Photoshop Lightroom will copy the healing spots from one negative to all negatives with similar spots.

[paulr]

Convinced that this would negatively impact sharpness, I built a carrier using clear optical glass. I wet-mounted the film to the optical glass and compared scans with ones made with the clam-shell holders. Even at 6000 dpi I couldn't see any difference in file detail.

Interesting. I wet mount my negs to float glass, and place on a shim to correct for focal height. It works but is a huge pain. I'd be interested in a solution like this if there's an easy way to Magyver it on a 4870 scanner.

[Peter De Smidt]

Interesting. I wet mount my negs to float glass, and place on a shim to correct for focal height. It works but is a huge pain. I'd be interested in a solution like this if there's an easy way to Magyver it on a 4870 scanner.

Back when I used a Canon 9950F, a consumer flat-bed scanner, wet-mounting did give me better scans. As a result, it looks like it's highly scanner depended as to whether wet-mounting is helpful or not. With the Cezanne the light source, for instance, is much bigger than on a consumer flatbed.

The AN texture on my clam-shell holders is extremely fine. It's finer than the texture on Focal Point AN glass. I don't know of a source other than Screen, and it's likely that buying one of the clam-shell holders will cost about what a high end consumer scanner does. You could try getting some AN glass and making a DIY sandwhich holder. The only way to tell if it impacts sharpness would be to test it. Scanning through another piece of glass would move the optimum scanning height a bit.

[Doug Fisher]

If you want to "make" your own, you will need to acid etch the glass. It is not an easy process, especially if you want to get it to a level of fine-ness that minimizes the chance of interfering with a scan. The process used on our glass that is made in Euopre actually uses an acid vapor etching process. The anti-newton glass we sell is super-fine but I still don't like to put another piece of glass between the film and scanner's optics if I can avoid it.

Doug
---
www.BetterScanning.com

[Peter De Smidt]

Speaking as someone who's acid-etched glass for ground glass, don't do this yourself. It is dangerous and very, very difficult to get an even etch. If I wanted to try what's being discussed, I'd buy some of Doug's AN glass.

[Preston]

If you don't know if a piece of glass is anti-Newton or not, try putting a fig newton on it. If it resists, its anti-Newton :D

John, John, John :rolleyes:

Certainly can't accuse either one of being non-Newtonian, can we?

--P

[ruilourosa]

How about a clear and even coat of mate or satin varnish? would it work?

Thanks