Split-Filtering w/ dichro head - blurring problems

greydreams · Oct 5, 2005

Hello people, I'm having an issue with split-filtering. I have a Beseler 23C XL color enlarger, and I was wondering if anyone else has experienced blurring of the image due to turning the knobs (to chage from full M to full Y) when split-filtering, and if anyone has come up with a solution. I would rather not use the cheapo gel filters, or muddle up the image by mixing M and Y in the same exposure.

peace.

Bill.

SuzanneR · Oct 5, 2005

I've been doing split filtering with a color head, though not a 23C, but a Beseler 67SVX or something. Never had this problem, but I turn the knobs VERY gently. All I can offer is some common sense suggestions, that you've probably tried... make sure the enlarger head is secured in place, and just be very careful with turning the knobs.

Good luck with it!

Bob Carnie · Oct 5, 2005

Hi Bill

I agree with Suzanne, you need to be very gentle using dichroic, that is why I like the condensor head, just gently flip the lid and add the appropriate filter.

I do not recommend this as I have not done so myself . But *You * could modify the mixing box quite easily by putting a slit into the plastic plate and put in a channel to slide the filters into the mixing chamber. You would have to use the 4x5 mixing box and I have an extra one if you are handy you could have it just take care of shipping.
You would then use white light which gives you maximum power and use the filters in a position that would not detract from the image quality.
This way I think the dials would be not needed which I know are a pain in the *** to use.

photomc · Oct 5, 2005

Have to agree with the previous post. Have a 23CII Dichro and a 45 Dichro and use both for split filtering..only time have had image blur was either from bumping the enlarger when moving the card for each step or because I forgot to turn the filter up or down before I turned the light on. Just be sure to give the enlarger a few secs to settle down before you turn the power on. BTW, have switched for the dichro light to just using green (soft) and blue (hard) filters under the lens and have been very happy with them.

Nick Zentena · Oct 5, 2005

I wouldn't say I'm gentle with either of my enlargers. Now I'm not saying I hit with a hammer but I don't baby it either. I have trouble seeing how changing a sheet filter is going to be any easier on the enlarger. How sturdy is the enlarger on it's base?

Paul Sorensen · Oct 5, 2005

I wonder if you are doing the changes during the exposure or between exposures. I have been using an LPL Saunders where the locking screw for the head height is broken and I am still not getting any blurring. I am guessing that it shakes a tiny bit when you actually use the knobs, but that if you do that between exposures, rather than in one long exposure, you should be okay. If you are doing this between exposures and still getting blurring...then...never mind.

Donald Qualls · Oct 5, 2005

FWIW, after a bunch of prints with distinct double images, I started simply hand holding the filter material under the lens for split filtering with my D2 and cold light. Just lifting the head enough to slip the filter in on top of the negative carrier would (sometimes) move the carrier enough to make a visible double or a much subtler blur.

This won't work well when I'm ready to dodge and burn, however (one hand to hold the filter, one to operate the switch, doesn't leave anything to dodge and burn with), so I'll probably wind up fabricating a simple frame that will fasten to the bracket for under-lens multicontrast filters (thoughtfully provided by Omega on each lens board and cone), to hold the 6x6 (or smaller, if I cut some smaller ones) filters. Then, of course, instead of just moving the filter to avoid projecting dust and scratches, I'll have to find a way to keep the filters clean and scratch free...

Ronald Moravec · Oct 6, 2005

Fasten the top of the column to a wall so you get rid of the vibration just as is done with wall mount enlargers. In your case, retain the baseboard.

Or buy a focomat 1c or V35. These will not shake at all and you need not add additional support.

I would do some careful side by side tests to see if you think anything is gained by split filtering. I only see a value if the neg requires low contrast to print, then I intensify the blacks with a short exposure with high contrast.

dphphoto · Oct 6, 2005

I second the idea of securing the top of the enlarger column to the wall. Calumet or B&H may have a kit.
If you're not concerned about the "latest," you could pick up a Leitz Valoy. Not auto focus, but dirt cheap. I got one a few years ago for $50. Simply the best 35mm enlarger I've ever had. Interestingly, it has a helical focusing mount for the lens. Dean

Robert Brummitt · Oct 6, 2005

If you're doing long exposures? Then you maybe you're getting negative pop. I use to get this alot then I started using a glass neg carrier or if you don't want the dust problem? Use two small pieces of archival tape and tape the neg taunt to the bottom of your neg carrier.

df cardwell · Oct 6, 2005

You know, if split filtering is causing problems, you might just try mixing the channels... it IS ALL THE SAME, after all.

lee · Oct 6, 2005

I have been watching and reading this for a day or two now and one thing that is not clear to me is when you are changing filters the light is out, right? You are not doing this in the middle of the exposure are you? Forgive me if that sounds stupid but you just never know without asking.

lee\c

Bob F. · Oct 6, 2005

df cardwell said:
You know, if split filtering is causing problems, you might just try mixing the channels... it IS ALL THE SAME, after all.

Not when it comes to dodging it's not. Also, some people find it quicker and easier to reach a suitable overall grade by splitting the exposure in to two. Different strokes...

Another option if the enlarger head is loose is to use the Ilford under-lens filter holders.

Cheers, Bob.

greydreams · Oct 6, 2005

I don't think mixing the channels is the same. Doing it that way, you can't expose for different times for different tonal values. It's do-able, but not as precise.

df cardwell said:
You know, if split filtering is causing problems, you might just try mixing the channels... it IS ALL THE SAME, after all.

greydreams · Oct 6, 2005

Yes, the light is out.

You've all given good suggestions. Thanks for the feedback. I'm going to try and secure the head a little better, and if that doesn't work, I might try and get the gel filter in the mixer somehow.

lee said:
I have been watching and reading this for a day or two now and one thing that is not clear to me is when you are changing filters the light is out, right? You are not doing this in the middle of the exposure are you? Forgive me if that sounds stupid but you just never know without asking.

lee\c

glbeas · Oct 7, 2005

Make sure you allow enough time after making the changes to allow the oscillations in the enlarger frame to die out before making the next exposure. This may take upwards of 30 seconds for some flimsey structures.

Maine-iac · Oct 12, 2005

greydreams said:
Hello people, I'm having an issue with split-filtering. I have a Beseler 23C XL color enlarger, and I was wondering if anyone else has experienced blurring of the image due to turning the knobs (to chage from full M to full Y) when split-filtering, and if anyone has come up with a solution. I would rather not use the cheapo gel filters, or muddle up the image by mixing M and Y in the same exposure.

peace.

Bill.

Been doing this for years with no blurring, but then I'm using a 45MCX which is quite a bit heavier than your 23, and the dichro head is also heavier and sits on the negative carrier more heavily, and so is less prone to movement. Make sure you've got your enlarger as rock stable as you can get it, and turn the dials gently, letting it settle before hitting your timer.

Larry

df cardwell · Oct 13, 2005

greydreams said:
I don't think mixing the channels is the same. Doing it that way, you can't expose for different times for different tonal values. It's do-able, but not as precise.

Well, I thought this was one of those ideas that was resolved 30 - 40 years ago. :confused:

I don't want to bring it up as a religious issue. Whatever makes good pictures for you, keep doing it.

You might secure the top of your enlarger chassis to the wall or ceiling.

Good luck.

.

Gary · Oct 14, 2005

Seems like the easiest answer, or at least what I'd try first, is to use a little WD 40 on the filter wheel. Make sure it moves like silk, and doesn't take the strength of Samson to turn it. The enlarger head shouldn't be disturbed.

Maine-iac · Oct 23, 2005

greydreams said:
I don't think mixing the channels is the same. Doing it that way, you can't expose for different times for different tonal values. It's do-able, but not as precise.

Agreed. It is not the same. Split filter improves local contrast within specific tones as well as offering more control to have varying contrasts in different areas of the print.

Larry

Split-Filtering w/ dichro head - blurring problems

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