When looking for some ANR glass for my camera scanning set up, I came across this video.
https://youtu.be/93ef2EDJPeg?si=maAQl9WUPZ7TlM02
I have a friend who is a custom framer and uses the glass mentioned in the video. So, a few bucks later and I have something that works perfectly.
thought I'd pass this info along.
That flick is an ignorant crock of BS. Real anti-Newton glass IS a specialized product. At one time I tested over a dozen types of them, plus alleged optical glass substitutes. Few still exist. The correct type is largely related to the angle of incidence of the exposing light, degree or magnification and contrast involved, and certain other optical properties. Common non-glare picture frame glass has little in common, and is likely to degrade the image or have its wholly different etching character become evident in reproduction.
How can you say it "works perfectly" if you haven't compared the result with the real deal? Incidentally, I have my own picture framing digs as well as a lab, and have tested samples of all those kinds of glasses and plastics too. That flick fellow wasn't even born yet when most AN glasses were actually made. And by starting his diatribe by accusing online storefront vendors of trying to promote the extra expense AN glass, he further displays his ignorance. You can't find AN glass in photo and electronics stores, and rarely ever could. It's a specialty which costs a lot more because it cost way more to begin with just to manufacture. And he particularly ridicules the Scan Tech product sheet - a company itself no longer in business - but if he had even a clue what that glass really is, it has very little resemblance to fragile thin non-glare picture framing glass. Secondarily, all the acid etching of a true AN glass has to be precisely polished afterwards for a distinct effect. It not just left raw abraded like cheap picture glass.
Perfect is the enemy of good enough. It's easy to compare using no glass to using a given piece of etched/ANR glass. If it provides an improvement, it's an improvement. ANR glass in larger sizes is almost unobtanium so I'm not sure there's an alternative anyways.
Misinformed is the enemy of everyone. Big difference. And that dude begins his flick with an outright falsehood. He should at least be honest and call it an experimental compromise instead. But I guess most DIY home flatbed scans are a form of compromise to begin with. He even calls the whole concept of AN glass an outright "scam". Well, in that case, Zeiss must be a scam corporation, because I once had an entire case of highly specialized Zeiss AN glass. I still use multiple types, and none of them bears any resemblance to cheap picture framing glass.
And in this case, if simply using a DLSR to "scan" a piece of film, a piece of enlarger carrier AN glass might be large enough to cover the sheet of film involved. With a bit of patience, that kind of item can often be still found.
A good inexpensive source for smaller MF film would be old Gepe AN glass slide mounts, which still turn up sometimes.
I got a dozen Anti Newton Glass 12X14" in locking frames with a big 10X10 Calumet Enlarger
10 years ago Near St Louis
During the 'Great Enlarger Purge' as criminal waste
Most enlargers were murdered for scrap
I rescued what I could...
Tin Can
If I ever post again, I'll have to choose my words more wisely. This glass worked really good in the way in which I intended to use it. Which is perfect for me. (Or, as Domaz said, "good enough")
I'm trying to get the best I can using what I can currently afford and thought I'd pass on the information.
Anyone have links on how ANR glass is actually made?
edit to add: I have negative supply 4x5 film holder with the acrylic ANR sheets. They are terrible. Not flat, collect dust like crazy and seem to scratch just by looking at them. So compared to that, this framing glass works way better.
did I insult you
not my plan
only expand light
Tin Can
No, not one bitOriginally Posted by Tin Can
Yeah - I'd agree with your own practical conclusion, relative to your own needs. It's just the way the guy on the flick tried to make a first impression by deliberately labeling the real deal as a scam. In that case, he should look in a mirror first, to find out the real meaning of a scam. You have to be careful with the promiscuity of online flicks these days.
I already hinted about the difference in manufacture. But different AN glasses have been made in different ways. Generally, a high grade of float glass was acid etched in a particular manner, in various specified thicknesses, and then a careful polishing process was involved afterwards. Some of the best examples, like Durst and Omega AN glass, have a slightly ripple effect to them. I even have quarter inch thick Belgian glass in my contact printing frames made that way. Less commonly, a special coating process was involved instead, over high quality optical glass flats.
The same major manufacturers of former AN glass are still very much in business and could no doubt offer these kinds of products again if someone was capable of paying for a large enough batch order. As far as the last supplier of custom cut AN glass in the US goes, it was apparently the pandemic and not lack of demand which shut them down. It's entirely possibly their remaining inventory is still laying around somewhere, without anyone to sell it.
DeYoung - Don't be afraid of posting again. There's always going to be some ebb and flow if misinformation is involved. Just part of the learning curve we all go through. Don't take it personal - I wasn't directing my statement against you. As far as AR acrylics go, there are ways to tame the static properties, and cleaning is possible if you're as careful with it as with lenses; but the bigger problem is that acrylic isn't dimensionally stable, and prone to warp a little. So no need to go further down that particular option; it's pretty much a dead end.
Tin Can - Yeah, I sure wish my lab friend had saved the carriers like I asked him to when he sent over a dozen Omega F and Durst L 8X10 enlargers literally to the dump once I told him I had no place to put them all. I did take the pick of the litter L184, and now use that, and its set of carriers, along with my other big enlargers. Just two more enlargers are left in his storage basement, almost impossible to move now. But over two dozen pro enlargers in all, 4x5 to 8X10, went straight to landfill when he retired that particular lab. It would have been nice to have had the extra reserve of AN glass from those machines, although I already had enough of my own for my own purposes.
Last edited by Drew Wiley; 8-Nov-2023 at 17:51.
Two things are required in order for Newton rings to form:
1) Imperfect contact (the rings will generally form in an air space around a point of contact)
2) Reflection between the two surfaces
Generally "ANR" glass was acid etched or possibly ground in some cases. Ideally you'd want the finest "grain" to scatter light just enough to prevent the formation of the Newton ring interference pattern but not enough to be visible in the print or degrade the image to any visible degree.
In theory a perfect (not possible) or near-perfect anti-reflection optical coating would prevent Newton rings. This sort of works but isn't 100% certain and obviously multicoated glass/flats are not budget items.
An alternate near-ideal solution (a variation on the etching theme) would be glass with so-called "sub-wavelength" or "nano-scale" surfaces. These are essentially higher performance anti-reflection surfaces than the usual thin film coatings on lenses. They are sometimes found in photographic lenses. For example you may have seen Nikon's reference to its "Nano Crystal Coat" that is sometimes on one or more surfaces/elements particularly in short focal length lenses. Canon etc. have their own versions of this. These surfaces are also used on lenses in high powered laser optics where conventional AR coatings wouldn't work. However as currently employed these technologies cannot be used in unsealed environments because they are delicate and cannot realistically be cleaned/dusted in a darkroom setting. So, obviously a no-go for negative carriers or contact printers (not to mention expensive).
More than you wanted to know about the ANR saga but anyway.
A good option remains the use of fixed out sheets of Kodak Tri-X 320 (TXP) placed between glass and film. TXP has just enough "tooth" on its base side (which was originally intended to better accept retouching dyes etc.) to usually be an effective anti-Newton ring spacer without degrading the image.
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