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Question about aligning unsharp masks

adelorenzo

Member
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Mar 10, 2012
Messages
1,420
Location
Whitehorse, Yukon
Format
4x5 Format
So, I decided to try unsharp masking. I'm working mostly off the information in Way Beyond Monochrome.

I made a couple of nice looking masks on Arista Ortho Litho film that read correctly on the densitometer to print a grade 3 negative at grade 5. I'm not using a pin system as I just want to experiment a bit before deciding to invest $1000 in new gear. Lambrecht says that you can align the negatives visually using a loupe on a light table, tape them together and print.

I've tried this but gotten odd results in the print. Here is my question: How do I know when the mask and negative are aligned? Is it when the image appears sharpest on the light table? Or... This might be hard to describe but if anyone can give me some pointers I'd appreciate it. I'm just not sure what I am looking for.

Here is the image in question, BTW. I'm getting some really weird effects in the trees on the upper right printing with the mask. I've done a decent print already so if I can't figure out the masking it's not the end of the world.


Yukon River near Miles Canyon by Dead Link Removed, on Flickr
 
What format are you working with?
 
This is a 4x5 negative and mask.

Prof Pixel not sure what you mean. do you think perhaps that my mask might be bending away from the film when it is under the enlarger? I'm using a regular non-glass carrier, perhaps I should try sandwiching them between sheets of glass instead?
 
adelorenzo,

I think Prof Pixel suggested that maybe your film isn't on a base (like glass) that is immune to size changes after processing, because you got it wet and dried it. I'm guessing that since you are working with 4x5 film, dimensional stability isn't going to be as big a problem (say as if you were working on 11x14 film).

I'm not sure how to tell if an unsharp mask is in register... I'd rather have it punched so there's no question.

A pin system doesn't have to cost money. Tape tabs with punched holes and a pair of register pins can be all you need.
 
OK, I see what you mean, the two images could basically be different sizes because they are on different film bases.

I could probably figure out a pin system. I guess I am just trying to get a sense of what kind of effect this would have a on a print, having never seen it with my own eyes.
 
OK, hold the phone. I just figured out one mistake I made -- I did not make an unsharp mask. I contact printed the film emulsion to emulsion so the image is a sharp positive. I need to either use a bit of material as a spacer or, at the very least, let the thickness of the film create the unsharp effect. On to round 2!

Thanks for the replies so far and I'll update how it turns out.

Edited to add: Thanks Bill, looks like you figured it out while I was posting.
 
adelorenzo said:
OK, I see what you mean, the two images could basically be different sizes because they are on different film bases.
Click to expand...

Yes, emulsions are gelatin and they can swell or shrink during processing and drying.


Here's a link to an article I wrote 10 years ago on USM. Yes, I know it's about digital processing but I compare the process to the analog method. It also contains a reference to the original USM article by J. Yule. The link: http://bit.ly/1ptMeFD
 
Better Film

I use FP4+ film (in 4x5 and 8x10 formats) for my unsharp masks and get good results. I used Arista Ortho for just about all my other masks but never quite got the resuts I wanted for unsharp masks. If you place the FP4 film at the bottom and place your negative, emulsion up, you will get a good mask. Both films emulsion up or both films emulsion down ~ let the base of the negative film be the spacer (vs. adding a spacer).

I use a pin system to align the neg and the mask but have done it also "by eye". Once you think they are aligned, use a little scotch tape to tape the corners together (with letting the tape touch the image on the negative, of course!).

Hope this helps.

BTW ~ Michaea provides some excellent suggestions for equipment and reading. Radeka's articles are fantastic and Bond's write-up on unsharp masking is wonderful
 
Prof Pixel thanks for the link to that article.

Thanks for the suggestions Micheal. I believe I've got all the info I need, I'll make new masks with some kind of a spacer so that the mask is actually unsharp and see where it goes from there.
 

Thanks for the suggestion, I'm already working with FP4 anyways so I have that option. I'll try the Ortho Litho again (nice to work under a safelight) and see where it goes from there. Good to know that the film base could be enough of a spacer.
 
Rather than a $1k dingus, make one.
The pins are available mounted on a plate about 1X1.5". Use a two/three hole punch to make a guide for the initial setup and tape or glue
the pins in place.

I've got a pair you can have for postage.
 

Quite right. google for Lynn Radeka.He sells a simple but accurate system and I believe it is far less than a grandIt's also pictured in Way Beyond Monochrome.
 
Unless you are just experimenting, aligning masks is a mega-headache without a matching punch and pin-registered contact frame. You ordinarily do not need a pin-registered neg carrier, because you can tape your mask to your original neg while on the contact glass pins.
Acetate-based films are not desirable for masking because they are not dimensionally stable. Most black and white sheet films are on polyester base, but some color sheet films are not, and most 120 films are not. Both FP4 and TMax100 are good films for unsharp masking. Ortho Litho is best at what it's name describes: high contrast lith masks, which are sometimes used supplementary to unsharp masks, after you have learned the basics. Then you need some diffusion material, preferably 5-mil mylar, frosted both sides, which you can get at a good art supply store. You can start your learning curve with a common developer like D76, but its better to have something which will work at low contrast like dilute HC-110. And you need to have a very clean workspace.
 
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