Scanning & Newton's rings

[john_b]

I usually use a film scanner to process 35mm slides and negatives but I find myself trying to scan some older format film - I think it may Kodak 848 - which won't fit my scanner.

The film is in strips of four frames. The images are 28mm square and the film itself only has sprocket holes along one edge. So one edge is almost 5mm wide while the other is only 1mm at most.

I thought I'd try a flatbed scanner and put the film strip on the platen with a thin sheet of glass to hold it flat. At first I thought I was doing quite well but it's only when you look closer that you start to see what I thought were some sort of diffraction patterns - swirly ellipses and so on - which I now find are called Newton's Rings. Bummer!

The best I can do is to put the film strip emulsion side down on the platen and try to hold it flat along the edges only, but since one edge is at best 1mm wide, this is a frustrating business to say the least.

If I had any hair left, I'd be pulling it out. I wonder, though if there's any other solution? Can you get some sorth of glass that doesn't cause this effect? I tried holding the film flat with a clear plastic CD jewel case lid but that's no use either...

...it was never going to be easy...;-(

[terrie]

I know I've read something about how to prevent Newton's Rings but I can't remember where and I'm a bit pressed for time right now...I'll do some looking and get back to you--tomorrow I hope...

Terrie

[iamback]

I knew I've read about this problem - but that was on a newsgroup, a bit hard to point to unless google groups managed to get hold of it. Still, try searching google for [scanning "newton rings" prevent] (without the [] but with the "") and you'll find plenty of tips.

"Wet Mounting" is the method I've read about, and it is mentioned here and there at least, but there are other tips you might want to try out.

[ktinkel]

I know I've read something about how to prevent Newton's Rings but I can't remember where and I'm a bit pressed for time right now...I'll do some looking and get back to you--tomorrow I hope...We had a wonderful thread on Newton’s Rings on the original CIS forum, but I do not seem to have (or cannot find) an archive of it. Maybe someone else kept a copy.

[pmkprog]

You'd have to used a special type of fluid that's like an oil for that and then use a piece of clear mylar on top and smooth everything out with a smooth lint free cloth. That'll work if your scanner can handle oil mounting. The stuff tends to get all over. It could damage the scanner if it's not made for that. You also need to have a light bar in the scanner.

[iamback]

For wet mounting I frequently come across mentions of "Kami scanner mounting fluid" which is non-oily, and much easier to clean afterwards.

[pmkprog]

Yep, that's the stuff we have here. It still tends to seep in places you don't realize.
I would probably have a better opinion of the whole system if I used it more.

[john_b]

"Wet Mounting" is the method I've read about, and it is mentioned here and there at least, but there are other tips you might want to try out.

Thanks for the tip which led to a number of references. I think the wet-mounting kit - as at, for example, www.wetmounting.com - looks fairly heavy duty and probably more than I'm really wanting to get involved with at the moment. Not to mention the expense...;-(

I did, however, spend an hour or so this morning making a kind of frame from bits of plastic and stuff which sits on the glass platen and does a reasonable job of holding the film flat. It ain't perfect but it's an improvement. And it does have the benefit of locating the film more precisely, as opposed to trying to line it up by eye.

Limited testing so far, but results indicate that it's definitely better to put the film emulsion side down. It means you have to remember to invert the image afterwards but I can live with that...;-)

...in any event, it's great to be making some progress at last!

[terrie]

john_b: I did, however, spend an hour or so this morning making a kind of frame from bits of plastic and stuff which sits on the glass platen and does a reasonable job of holding the film flat.Glad that you've found a reasonable workaround...

I wonder if you could have a framing place do a custom cut mat--2 pieces for top and bottom--and have them cut the mat opening in the mat board sheets the same size as your scanner bed with the hole in the middle of the mat board. Depending on the size of the negative, you might be able to have multiple openings so that you could scan more than one negative at a time.

You could use hinging tape to hinge the "top" and "bottom" mat board together so that it would be easier to place the negative.

Terrie

[john_b]

Glad that you've found a reasonable workaround...
Terrie

Well if I was scanning more of them I'd probably spend more time to get something a tad more functional. I should correct my earlier post - I think the film format is Kodak 828, not 848.

I like your idea of the 'hinging tape'. Hadn't thought of that and I think it could work well.

[terrie]

john_b: I should correct my earlier post - I think the film format is Kodak 828, not 848.Don't know the film...is it like 2 1/4 size???


>>I like your idea of the 'hinging tape'. Hadn't thought of that and I think it could work well.

Yeah...and you can probably use just about any sort of tape for the hinge...

You might also take a browse around the B&H Photo (http://www.bhphotovideo.com/bnh/controller/home/) site as they might have some sort of (inexpensive) holder...

Terrie

[john_b]

Don't know the film...is it like 2 1/4 size???

I wish it was 'cos it'd be easier to deal with...;-(

It's 35mm wide but the image (28mm square) is pretty well all on one side such that there's a margin of 6mm along one edge but only 1mm along the other...

...which means that any holder would have to be finely engineered to keep that 1mm edge in place; even more so if the film has some curvature to it.

Which is why the tempting solution was to put a glass plate over it to keep it flat - but then we run into the problem of these pesky Newton's Rings. I'd have been happier if he'd just stuck to marketing apples and inventing gravity...;-)

John

[ktinkel]

. . . the problem of these pesky Newton's Rings. I'd have been happier if he'd just stuck to marketing apples and inventing gravity...;-)BTW — Elyse found some of our old threads on this topic and posted it in a separate read-only message. You may want to take a look just in case you find some other ideas.

Newton Rings (archives) (http://www.desktoppublishingforum.com/bb/showthread.php?t=3578)

[john_b]

BTW — Elyse found some of our old threads on this topic and posted it in a separate read-only message. You may want to take a look just in case you find some other ideas.

Thanks for that - it seems like going down the route of wet-mounting as Marjolein suggested could be a bit of a faff, though I don't doubt the the results are probably as good as you can get.

I'm sure that transparencies were sometimes mounted between two thin glass sheets - similar to a microscope slide - and held in standard 5cm size plastic frames. In fact, I've got a boxfull of the glass mounts - the local photographic shop was going to throw them out so I took them off his hands. I wonder if they used a small amount of liquid of some sort or other to prevent the rings showing up?

[ktinkel]

Thanks for that - it seems like going down the route of wet-mounting as Marjolein suggested could be a bit of a faff, though I don't doubt the the results are probably as good as you can get.

I'm sure that transparencies were sometimes mounted between two thin glass sheets - similar to a microscope slide - and held in standard 5cm size plastic frames. In fact, I've got a boxfull of the glass mounts - the local photographic shop was going to throw them out so I took them off his hands. I wonder if they used a small amount of liquid of some sort or other to prevent the rings showing up?May have. Much of that discussion related to drum scanners, which have different possibilities than flatbeds (and most of them cost a lot more, too).

[iamback]

I'm sure that transparencies were sometimes mounted between two thin glass sheets - similar to a microscope slide - and held in standard 5cm size plastic frames. In fact, I've got a boxfull of the glass mounts - the local photographic shop was going to throw them out so I took them off his hands. I wonder if they used a small amount of liquid of some sort or other to prevent the rings showing up?My dad has always mounted all his transparencies between glass sheets (manually) - glued together with paper strips, no plastic frames as development would do. No fluid involved at all, and when the slides were projected newton rings were a frequent problem, in spite of speical glass used - mostly as a result of the heat of the projector lamp. Still, the manual method (carefully done) was definitely better than the machine-mounting done at processing labs.

[terrie]

john_b: It's 35mm wide but the image (28mm square) is pretty well all on one side such that there's a margin of 6mm along one edge but only 1mm along the other...sounds pretty odd...'-}}


>>Which is why the tempting solution was to put a glass plate over it to keep it flat - but then we run into the problem of these pesky Newton's Rings.

What about using glass to keep it flat and then using a mat (or whatever) over the glass???


>>I'd have been happier if he'd just stuck to marketing apples and inventing gravity...;-)

ROFL!!!

Terrie

[john_b]

No fluid involved at all, and when the slides were projected newton rings were a frequent problem, in spite of speical glass used - mostly as a result of the heat of the projector lamp.

Yes I still have a projector up in the attic but can't see it ever being used again...;-(

The sad thing to me is that you would go to exciting and far-flung places in your youth but now have barely any record of it because film was, in relative terms, quite an expensive item and you were very conscious of this when deciding whether or not to take a picture. God's bum - I can't believe I just wrote that!