Newton's Rings, Focomat 1C Enlarger

[Loren Sattler]

Does anyone have a solution for Newton's Rings? My Focomat 1C has the N condenser which is intended to prevent the issue but I am constantly fighting Newton's Rings especially in lighter areas of a print such as the sky. See sample print and other information attached.

I wonder if I aggravate the problem when cleaning the condenser with alcohol prior to making final prints?

 

[jtk]

Rubbing alcohol always leaves a deposit. Perhaps that's the issue. Lens cleaning fluid, perhaps.

 

[grain elevator]

Is that a glass carrier? If so, Newton's rings can sometimes come from the emulsion side as well, T-Max 100 is notorious for that. I haven't found the silver bullet against Newton's Rings yet, while keeping the negative flat... AN glass has given me weird patterns on the print. But one solution can be going glassless at least on one side. You can try with a simple mask that you cut from paper, which gives some distance between the glass and negative.

 

[AgX]

The OP's enlarger has a condensor lens that the same time acts as upper cover glass.
But that framing of the film frame might work.
,

 

[grain elevator]

The OP's enlarger has a condensor lens that the same time acts as upper cover glass.
But that framing of the film frame might work.
,

I assumed as much, and that condensor lens has an AN pattern, yes? Seems unlikely that it doesn't work, therefore my idea that the Newton's rings come from the emulsion side.

 

[RalphLambrecht]

Does anyone have a solution for Newton's Rings? View attachment 242589 My Focomat 1C has the N condenser which is intended to prevent the issue but I am constantly fighting Newton's Rings especially in lighter areas of a print such as the sky. See sample print and other information attached.

I wonder if I aggravate the problem when cleaning the condenser with alcohol prior to making final prints?

You need anti-Newton glass on the shiny side of the negative.

 

[Loren Sattler]

Ralph, the Focomat 1C utilizes anti-Newton glass on the condenser that presses on the shiny side of the film. (see photos in the original post of the condenser marked "N" and a photo of the original owners manual explaining the "N" condenser.) For some reason, my condenser is not working properly. Last night I cleaned the condenser with lens cleaning solution and enlarged the same negative again with similar results. See attached scan. The Newton rings have migrated to a different part of the print from the photo in the original post.

I could probably fabricate a mask that would sandwich between the negative and the condenser and create a small gap that could eliminate the rings, but that would defeat the Focomat's greatest asset......a fast working foolproof method to flatten negatives while focusing automatically.

I am curious if other people have had this problem with their Focomat and figured out a solution? Can the anti-Newton glass be replaced or reworked easily? Is there an issue with the film surface? Perhaps the film surface on Tmax-100 is more prone to the problem? These enlargers have been popular for over 50 years. Do other people have this issue with their Focomat 1C?

 

[grain elevator]

Aha! TMX! Then I bet your Newton's rings are formed on the emulsion side.

 

[AgX]

Last night I cleaned the condenser with lens cleaning solution and enlarged the same negative again with similar results. See attached scan. The Newton rings have migrated to a different part of the print from the photo in the original post.

If a cleaning fluid leaves a film on a surface, it nevertheless may work perfectly on a plain, lens but anti-Newton surfaces should be cleaned with something that for sure evaporates completely.

 

[Loren Sattler]

AgX, can you suggest something that evaporates more thoroughly than rubbing alcohol or lens cleaning solution?

 

[Loren Sattler]

Grain Elevator, there is no glass on the emulsion side, only on the shiny side of the film on a Focomat 1C.

 

[grain elevator]

Ah I see, then I have nothing. That the emulsion side is so smooth that it can also give NRs has been my problem with TMX, not buying any more, but it's gotten too expensive anyway... but your problem then is something else. If it was any other film, you could try turning it upside down, if the focusing can be adjusted for that.

 

[Loren Sattler]

I believe I have found the problem.....my condenser is missing the anti-Newton ring accessory glass filter that is mentioned in the owners manual. Attached is a photo of the missing part from the glennview.com website specializing in Focomats.

 

[Patrick Robert James]

If you find the price of the anti-newton ring filter too much for you, you can use the anti newton glass out of a 6x6 slide mount. It fits perfectly. I did that with the first Focomat i had since the newton rings drove me crazy.

If you don't want to bother getting the AN glass, or if you need a solution now, you can use a very light dusting of Corn Starch on the neg. By light dusting I mean poof the Corn Starch in the air then wave the shiny side of the neg through it. That works perfectly and there really isn't anything to clean off. A little puff of air will take care of it.

Another thing you can do in a pinch is to take a multi coated UV filter out of it's ring and place that between the condenser and the neg. That could solve your problem too. On my Saunders I get newton rings sometimes off the emulsion surface of Acros, but I never get them on the Focomat. The Saunders glass is not coated and the glass I use for the Focomat is. Makes a difference.

Hope that helps you Loren...

 

[AgX]

AgX, can you suggest something that evaporates more thoroughly than rubbing alcohol or lens cleaning solution?

Both terms are ambiguos.

 

[choiliefan]

The part shown in the above pic isn't a glass filter.
It's a 3mm spacer ring.
This is mentioned in the page of the manual you cited.

 

[Patrick Robert James]

The part shown in the above pic isn't a glass filter.
It's a 3mm spacer ring.
This is mentioned in the page of the manual you cited.

There is a spacer for the column, but that is different. It is made for using a different thickness easel.

The anti newton glass filter should come with a spacer that goes around the neck of the condenser inside the enlarger so the condenser doesn't come down as far when it descends. If you don't have the spacer the condenser with the filter puts more pressure on the neg which makes it easier to scratch the neg (and the filter) if you move the neg with the condenser down. If you don't have the spacer you can make one from a wire hanger. Ask me how I know....

I actually use a neg holder with a thin piece of coated glass glued to it that the neg rests on so the neg gets sandwiched between the coated glass on the bottom and the anti newton filter on top. Makes for a flat neg and very sharp prints. I got the piece of glass from Edmond Optics if anyone is interested. You could also use coated filter glass as well but filter glass can be pretty thick. I have one carrier with a coated filter that I use for Minox on the Focomat that is cropped out with rubylith. Thickness doesn't matter since I change lenses when I am enlarging the Minox negs.

Hope that helps someone.

 

[Loren Sattler]

Thanks for all the responses. I have purchased a Focomat AN filter, it should arrive in the next couple of days. I will report later.

Patrick Robert James, your information on the spacer is very interesting, thank you. I will be in touch if I have trouble fitting the filter to the enlarger.

 

[Christiaan Phleger]

Yes quite interesting; I would also like to know the Edmund coated glass that you used, many thanks

 

[Patrick Robert James]

Yes quite interesting; I would also like to know the Edmund coated glass that you used, many thanks

Found the receipt. Looks like they still sell it after 12 years...

https://www.edmundoptics.com/p/508-x-508-x-1mm-high-efficiency-window/9281/

I attached it with Canada Balsam. You should also paint the edges. I use Speedball Super Black India Ink for blocking light that goes through the edges of the glass. I also put the ink around the perimeter of the anti newton filter. Gotta get rid of those pesky light leaks!

 

[Loren Sattler]

Good news. I purchased a Focomat filter online. Yesterday I reprinted the problem photo posted earlier....no Newton's rings so I should be good going forward. Attached is a photo of the filter. It slips on the bottom of the condenser.

The purpose of the spacer is to raise the condenser vertically to accept the filter. I have enough clearance to slip the negative into the reduced space but I am going to pursue installing a spacer to make the process easier.

Thanks for everyone's interest.

 

[choiliefan]

Wow, I thought you already had one on your enlarger.
Doh!

 

[Geoff Bartlett]

If a cleaning fluid leaves a film on a surface, it nevertheless may work perfectly on a plain, lens but anti-Newton surfaces should be cleaned with something that for sure evaporates completely.

Any suggestions will be welcome. I cleaned my Meopta ANR negative holder plates with isopropyl and am now getting some Newton rings. Perhaps an extended cleaning with a new microfiber lens cloth?

 

[AgX]

Isopropanol is volatile and leaves no residue as long one uses it long enough to take off all the dissolved grease and dirt from the surface.

However there could evolve a problem, I did not hint at and that might be the case with your AN-pane:
The cleaning solvent took not only off grease and such, but the AN-surface too. In case that was not etched or otherwise structured glass, and thus permanent, but a soluble coating.

 

[Geoff Bartlett]

Isopropanol is volatile and leaves no residue as long one uses it long enough to take off all the dissolved grease and dirt from the surface.

However there could evolve a problem, I did not hint at and that might be the case with your AN-pane:
The cleaning solvent took not only off grease and such, but the AN-surface too. In case that was not etched or otherwise structured glass, and thus permanent, but a soluble coating.

Thanks

I'll be hoping for just inadequate cleaning... otherwise, new ANR glass. While I'm here, is it both sides of the glass sandwich that are ANR, or just the top (non-emulsion) side?