Massive contact printing troubles

[kjsphoto]

Well as of late I have been using my contact-printing frame on a daily basis with no troubles at all, but today I noticed I am getting Newton rings everywhere, all over the place. I took the glass out and washed it several times and let dry. Then even went so far as to dry with a hair dryer and still everywhere! Nothing I do can get rid of it, nothing!

ERRRRRRR

Now here is the thing if I put the emulsion side to the glass no problems and no rings but if I flip it over the correct way slippery side to glass rings everywhere to the point I cant make a print without it showing up.

I have a spilt back frame. What can I do as I have prints that have been ordered that I need to get out. I have never seen it before until today!

Please help or any advice would be greatly appreciated.

Thanks,

Kev

 

[David A. Goldfarb]

There are two types of glass used to eliminate Newton's rings--textured glass and anti-reflective glass. Steven Shuart sells AN glass, but I'm not sure which type. If you have a framer near you that sells Denglas, it has an anti-reflective coating, so it might supress Newton's rings.

There is also an Anti-Newton spray that acts a bit like a dulling spray, and that could work. Haven't tried that one myself.

An old trick is to brush the shiny surface of the neg with cornstarch or talcum powder. Sounds messy and I haven't tried it myself.

Are you shooting T-max film? I find I get more Newton's rings with T-max. You might look for a film that has retouching surfaces on both sides, which will suppress Newton's rings.

 

[kjsphoto]

I am using HP5 and have made tons of contacts in the last month. But all of a sudden today I started getting them. I have no idea as to why and never had them before.

 

[JBrunner]

I haven't ever had this happen to me, but if it did... what have have been the changes since you last printed successfully? Temperature, humidity, paper, etc?

Or maybe more likely...

Have the springs on your frame weakened? Try inserting a piece of mat board behind the paper to restore pressure.. I believe that to form the rings there would have to be intermittent contact, but I'm not sure.

 

[kjsphoto]

The only thing that has changed is the tempeture. It has heated up big time lately. That is the only thing I can think of. I just hope I can print as I am in a bind...

 

[Donald Miller]

Kevin,
From what I understand, Newton's Rings occur in relation to the relative humidity and are most pronounced under situations of higher humidity. I don't know where you live in Ca but here in Phoenix we recently switched to the annual summer monsoons when the dew point climbs up into the mid 50's and low 60's. So it may be that you have had a change of similar nature.

I have heard that a light dusting of talcum will sometimes solve the problem without resorting to AN glass. If you decide to try this, I would apply the talcum to the glass surface (immediately adjacent to the film), shake it to distribute, and then pour off the excess.

I am not sure that Denglass would serve to eliminate the problem since it is a parallel and smooth glass surface. The problem is due not so much to reflections as it is to humidity and altered contact between the film and glass.

 

[kjsphoto]

I am up near Yosemite about 3500 feet. Tonight it says it is at 40% humidity.

I am going to give up at this point. I am going to try this; 1/4" closed cell foam on enlarger baseboard, then a tight weave cotton flannel on top of that. Then the paper then the neg then a 11x14 1/8" peice of glass on top of that. I am hoping the the foam and flannel will keep even contact with just the weight of the glass on top.

 

[David A. Goldfarb]

Newton's rings are interference patterns caused by reflections between a curved surface (the film) and a flat surface (the glass). Some enlargers and scanners have glass with anti-reflective coatings, and this is described as "Anti-Newton Glass," as is glass with a textured surface. I've had both, and while the textured surface is more effective in reducing the problem of Newton's rings, the downside is that a textured surface can also sometimes have an effect on resolution.

 

[kjsphoto]

Well I have tried everything and no matter what peice of glass I use I am having the exact same problem. I had the AC running today and that is the only thing I can think that changed. I will have to wait until tommorrow... So frustrated...

Thanks for all the replies...

 

[Dan Pelland]

Hope you've had some success resolving this problem - or at least managed to get a little sleep... I read your posts in addition to your email, and it sounds like you may have eliminated the frame as a source of the trouble. I'm glad to hear that, but still hope I can help. I'm not clear on one point... Have you printed this particular negative before without the Newton's Rings showing up? I guess that's is an obvious question, but it's the only one I can think of. It sounds like you're down to either the film or the environment as the cause.

 

[Robert Hall]

Kev, I use a sheet of anti-glare glass from the frame shop, that has helped me.

 

[Jim Noel]

One of my contact frames from the 1940's has a glass which is a very fine ground glass, finer than nay I have ever seen on a camera. I never get Newton's rings when using it so it is my frame of choice when the humidity gets above about 40%.

You might try using the ground glass out of your camera.

To answer the questio I know will come, No, I have never seen any loss of sharpness using the ground glass.

 

[waterlily]

I had the same problem with TMY 400 recently after not having the problem before. I also think that humidity had much to do with it. I am in the Pacific Northwest. I did like Robert and went to a glass shop and got a large piece of non-glare glass for $5 and cut it to sizes. I see no difference in the prints from using regualr glass, except that I no longer get the Newton rings. Jim may have a frame that someone changed the glass to non-glare, also. It is a very fine texture. You have to look at the glass at an angle to see the difference between the sides. Inexpensive and effective solution for me.

 

[Alex Hawley]

Kevin,

I would suspect its something to do with the humidity/temperature conditions that you are currently experiencing. If you can run the a/c, the humidity will dry out out and the temperature will stabilize.

Alex

 

[Donald Qualls]

Just a thought -- is it possible you could have had the glass out of the frame to clean it, and got it back in with the anti-Newton side up instead of down?

 

[Neil Miller]

Hi - I've heard that a light spray with hairspay on the side of the glass facing the negative works - people say it works with scanners, too. If it doesn't work, you can just clean it off. I expect it works by laying down a thin, non-even film that stops the interference pattern occurring, but I have not tried it myself.

Regards,
Neil.

 

[rmolson]

Newton Rings

I am dating myself but years ago I was a scanner operator. We taped sheet film color transparencies to the polished drum of the scanner. Newton rings were a headache. We used a small atomizer with off set spray powder from the press room which was basically corn starch .Holding the transparency in one hand and the atomizer in the other a weak spray was sprayed into the air and the transparency waved through it. It sounds weird but that would be enough to allow a tiny amount of powder to collect on the surface of the film and prevent Newtons rings between the emulsion and the drum surface.If you could see the powder you knew you had sprayed too much.