Newton rings on 8x10 scans - Epson 4990

Is there an anti-newton ring solution that works? There seems to be

a lot of discussion but I haven't seen much resolution. These rings

are killing me. I've tried scanning the sheet upside down, right

side up, weighed down around the edges...and I get different NR

patterns with every scan. <br><br> If I get a big sheet of anti-

newton glass and lay it down on the neg to flatten it flush with the

scanner glass will that fix the problem? <br><br> What about making

something to hold the film off the glass? I'd guess that the centre

of the would sag and touch the glasss anyway. Any help here would be

appreciated. <br><br> (I will be contact printing eventually, once

I get set up for it, but I also like the option of making bigger

prints, too.)<br>

Robert

Others can probably offer a lot more or better help than me, but here goes anyway...

 

The biggest negative I work with is 4x5, and I use the holder from epson for scanning these. Placing a negative on the glass has NEVER worked well for me. Here's what I did with the previous (non-photo) scanner. I printed (contact) and then scanned that print. If I were doing 8x10, this is probably the route I would take.

Iseems you either have Newton rings, with plain glass, or pick up a pattern in smooth highlight areas, with the Anti-Newton ring glass. Typical case of pick your poison!

 

You know the little plastic things they put in the center of pizza boxes, to keep the lid from sticking to the pizza topping? Maybe something like that, between film back and glass? But then, you have to clone it out in each picture, and your film is no longer flat corner-to-corner.

 

Wet mount? Big step. New hassles?

 

Maybe try various different manufacturers of AN glass, to see which is least deleterious to scan quality?

I'm surprised that you get the rings whether you place the sheet "right side up or upside down" (by which I assume you mean whether you place emulsion side down or base side down). It's been a few months since I scanned an 8x10 negative with the Epson 4990 but whether I got Newton rings or not depended on which way the negative was placed on the scanner, base side down or emulsion side down. One of those ways produced Newton rings, the other didn't, but I've now forgotten which was which. I just placed the negatives on the glass. I also scan 4x5 and don't get Newton rings either way but that's probably because I use a holder and 4x5 is small enough so that it doesn't sag. Sorry not to have a suggestion for you but I thought it might be slightly encouraging to learn that Newton rings aren't an inevitable fact of life with 8x10 negatives.

That is encouraging Brian. And yes, I meant emulsion down and base down...maybe that expression I used is a weird Canadianism...wasn't thinking. <br>

Right now I've got the negs stuck between the pages of a heavy book in the hopes that they'll be flat enough to sit flush, perhaps avoiding ring formation. We'll see.

first my disclaimer-

 

I don't know anything about scanning and don't even own one-

 

that said,after reading your discription I'd try a piece of mylar,possibly pink or orange- didn't I read somewhere about C-41 film scanning well because of the color of the base?

 

might be worth a try -heh

Robert,

 

I use a 4990 and one thing I've found is that some films seem more prone to the dreaded

newton ring problem - even when placed emulsion side down on the glass. Tmax comes to

mind as being the worst while the east European sourced films (Forte, Bergger, etc) have

been problem free. FP4/TXP have also been relatively free of newton rings when scanned

emulsion side down. I have no idea why this may be.

I've been using Tmax, so that could explain it. I'll see how the Efke I just loaded scans.

Thanks for your help.

I scan 4x5 and 5x7 on the 4990 all the time. If you just lay the negative emulsion-

side down onto the glass, with nothing on top, you will avoid NRs most of the time.

The negative may have some curl, especially after it heats up on the glass, but the

DOF with the 4990 is sufficient to keep the negative in focus.

 

If the curl is excessive, take a piece of glass, position it over the negative, but shim it

with something thin so the weight of it is not on the negative. That should suffice to

hold the negative flat enough within the scanner's DOF. In an ideal world it should be

ANG, but since it will not be pressing against the flat of the negative, but against a

corner, it's not critical.

 

Some negatives will give you NRs no matter what. As a rule, they are thin negatives,

or negatives with lots of black in the image, or negatives with very slick emulsions.

Anything that takes the buffer of the emulsion down to the film base, will make NRs

more likely. Tech Pan is a film that drove me nuts on the scanner. For films like this,

you can wet-mount the negative to the scanner glass using any of the commercially-

available mounting fluids. I've also heard of people using talc or baby powder or

whatever -- lightly dust the glass and then lay the negative on top. The powder does

not scan but it breaks the film's contact with the glass and solves the problem. (So I

am told.)

 

Sanders McNew

 

www.mcnew.net

Robert,

I am not familuar with the Epson 4900 but others saying that it uses a film holder for 4x5 says what will work. Do you have a Tap Plastics or simular store that sells plastic sheets? My Microtek 8700 has a 8x10 glass that has not caused any newton rings but the negetive shifted when silding the holder drawer in so....I went to Tap and got a sheet of 1/4 inch thick acrylic, cut the center portion out equivelent to the image area of an 8x10 leaving about 1/8 inch edge of the sheet of film beyond the opening on all sides. I futher modified the sheet to fit the transparency drawer.

 

I lay the negetive emultion side up or down and using blue painters tape secure the negetive by each corner square to the opening and tape along the long sides also all with 1/2 to 3/4 inch long strips of tape.

 

Now a sheet of acrylic of any color or clear 1/8 to 3/32 inch thick cut to the size of the 4900's scanning glass with the inside removed to approximate the useable image area of the 8x10 negetive and with said negetive tpaed along the edges, to elimate sag and slipage, to the self made sheet film holder sholud cure the problem.

 

 

To cut the acrylic I drilled 3/8 inch holes at each inside corner, clamped a length of angle aluminum, squared to outside edge, as a guide for my jig saw so that the blade was cutting where I wanted. A variable speed jig saw works best.

 

Charles

This has been a huge problem for me, so much so that I've considered ditching 10x8

altogether. On several occasions I have seriously considered finding a really tall building to

throw scanner from.

 

I shoot mostly color negative film these days. I have tried scanning the negatives both

emulsion-up and down, and neither seems to be better than the other, at least with color

film. Sometimes by flipping the neg I can move the newton rings, or reduce them, but

they're almost always there. If they are in a sky or other simple area, I can clone them out,

but they are a huge problem. I haven't quite figured out why, on rare occasions, I don't get

the rings. I think it might have something to do with humidity and/or temperature and

how these affect film curl.

 

Someone should really come up with a mid-range scanner to fill the gap between epson

flatbeds and drum scanners. Seems like there is a huge difference between the two.

Another word of warning is that regardless of the file size, the print sharpness for 16x20

prints leaves a lot to be desired. In the meantime, I'm probably going to either settle on

using the epson only for web and proof scans, and renting darkroom time to make large

c-prints, or switching to 5x4 and getting an imacon scanner. Sending out for drum scans

is simply not economical for the long term, and I hate sending negatives out. If the

imacons could do 10x8 film, I'd buy one in a second.

 

I've been thinking that a good solution (other than wet mounting, which I'm sure works

well but sounds like a mess), is making some sort of negative carrier that would clamp

along the long dimensions of the film and pull it somewhat tight so it doesn't sag and is

held just above the glass. It would have to be well made to work, probably out of metal,

and I don't have a metal shop, so it would probably be expensive and might not even

work. You might be able to make a mask out of plastic that would hold the negative, and if

you taped the neg to the frame tight enough with slide tape you could probably get it to

not sag. Just thought of that, I'll have to give it a try.

I never thought of the film brand being relevant to Newton rings but FWIW I use Ilford HP5+ in 8x10.

I think I'm going to try to come up with a solution to lift the neg a touch above the glass and employ the "Tape in place" technique to keep it from bowing onto the glass. I've never had a NR problem with the 4x5s in a holder, so rigging a home-made holder seems like the best idea to try first. If it works I'll let you know.<br> Thanks for all the replies. <BR>R.

You might get in contact with Focal Point-386 860 3918. They cut

all different sizes of AN glass for both scanners and optical

negative carriers.

From may understanding, as long a neg is pressed tight,

nothing should be visible.

I've had two use two sheets of AN in my optical carriers. And I've

done that for awhile. I've also compared both types of prints, with

one and two sheets, using a diffusion type head.

I know its not scanning though.

One more thing. I've printed a lot of 35mm masked slides. For

newton rings between the slide and mask, I found I could shimm

them apart using layers of tape to separate the two. You could

cut a mask to tape to the emulsion side of the neg, streching it

flat and tight, then take another mask for the top. I don't know if

the air gap will ruin any resolution. You know better.

Most scanners have a moderate depth of field so that an object on its glass or slightly above will be in focus hense the thickness suggestion in my first post. A homemade holder that holds the film within 1/32 of the same distance that a factory holder holds the film from the glass should be acceptable on any make of flatbed scanner.

 

Charles

I have been thinking of ways to get a better scan on my 2450. (The 2450 is not good enough to get rings). The newton rings are a result of interference, this link has a good description of the problem.

 

http://www.fas.harvard.edu/~scdiroff/lds/LightOptics/NewtonsRings/NewtonsRings.html

 

So, lets remove the glass! Instead of tossing out the scanner, take out the glass and replace the glass with a black metal plate with a slightly less than 4x5 hole in it. Tape the positive/negative over the hole and scan this. As there wont be reflections the rings should go away and you get top resolution scan to boot.

 

In theory. Who wants to try it?

There is a very simple and inexpensive ($2.00) solution to this problem - hair spray. Yep - been using it to scan 8x10 negs on a 4990 and it works great. If anyone wants details on how to do this, feel fee to email me: Charles.McMillion@gmail.com

Here I use holders to keep the negatives or tranys off the glass, and NEVER get Newton rings. Why create trouble and headaches? If you place 2 objects in contact, you are going to get an interference pattern, like basic Optics 101 from 3 centuries ago. Our first pro flatbed was a 300 dpi unit that cost more than a Hasselblad kit over a decade ago. In service bureaus it was well known not to create newton rings by NOT laying the originals on the glass, the salesman told up this, the seminars, the instruction manuals too !

With our ancient 1 decade old flatbed, they had some dinky few thousands of an inch balls that one used to float the negative above the glass, one air brushed them out. Since these are old ideas, they MUST be discounted as being obsolete, old hat, garbage . :) Folks did this with mapping before photoshop, thus yet another reason to not use it.