Printing issue, light spots in one corner

[harlekin]

I'm having a bit of trouble with printing 8x10s from my 4x5 negatives. I'm getting a better feel for my exposure and development, but I'm noticing some flaws on the prints. I was having trouble with white lines across the top and bottom of the print, but narrowed that down to a development issue. (the fins on the lid of the Orbital tank.) That print also had a lightened area on the upper left portion of the print. The light area had a rough shape to it, possibly pentagonal, but very blurry. I stopped the lens down a click to get the print a bit darker and near where the lightened area was on the previous print was a very distinct circle. The circle is solid light grey, about 3/16" diameter. There is another circle of similar size, but much dimmer in the extreme corner (the same region of the paper) and a pair of smaller and even dimmer circles next to it.

At first I thought it looked like some sort of lens flare, but lens flare on an enlarger would make dark spots, wouldn't it? Has anyone experienced anything like this? What can I do to fix this?

My enlarger is an Omega D2 with a Dichroic II color head. I was printing VC at about grade 1 (Y68, M10). The lens is a Beseler 135mm. The first print was at f/16, the second with the better defined circles was at f/22. The exposure was 15s. The paper was Ilford Multigrade fiber and was developed with Ilford multigrade developer (1+14) for 3 min at 72F in a Paterson Orbital on the motor base. (Followed by a 20s citric acid stop, 2 min rapid fixer (1+9), and a few rinse baths). (Also, if anyone has some pointers for my development process, I'd be happy to hear them.)

[Gem Singer]

Chad,

Nothing wrong with your print developing procedure.

Check the negative with a loupe to see if the circular spots show up in the negative.

Sharpening after closing down to f22 hints at something blocking the light path above the negative.

Remove the lens from the enlarger and check the light coming through the enlarger.

Posting a picture of these defects on this forum would help with the diagnosis.

[harlekin]

I haven't been able to find these spots on the negative, but I'll definitely double check. I'm not very good at evaluating negatives yet. I may toss the negative on my scanner to have a look at it. My scanner isn't very good, but it helps me debug things from time to time.

My negative carrier is glassless and I have tried to seal up light leaks on the enlarger (though it could probably use another pass). My darkroom is a small closet with a vinyl cloth sealing the door, but the other white walls aren't ideal for enlarging. The spots are very well defined, though, so if it is a leak, it would have to be a pinhole.

I'll scan the print when I get home tonight and post it.

[Louie Powell]

Can you scan a print so we can see the spots?

If by "spots" you mean that a corner is lighter, the problem may be enlarger alignment.

But if you means clouds of lighter density surrounded by normal density, then the problem could be film development, or even defective film.

[ic-racer]

How is the diffuser on the bottom of your 4x5 light mixing box? It needs to be perfectly clean. New diffusers are available if you can't get it perfectly clean.

[tgtaylor]

I had a similar problem with a Beseler 45S Color head a couple of months ago. It turned out the the diffusion glass had a scratch on it. I bought a used 4x5 mixing chamber with a good diffusion glass for $10 and swapped the glass which eliminated the symptoms.

If you clean the glass and inside of the mixing chamber that will eliminate some otherwise inexplictable "dust" on your prints.

Thomas

[harlekin]

Here's a quick scan of the print with the spots. The spots are all around the upper left corner of the print.

http://lh4.ggpht.com/_36bKpUBDfyo/S_HObdj97II/AAAAAAAAABc/TQWcXPh0610/s800/fallscreek.jpg

[Gem Singer]

Dark spots on the negative=light spots on the print (and vice versa).

If there are no dark round spots on the negative, they could have been formed from air bubbles that were trapped under the print paper when it was placed in the developer.

The sheet of paper was not agitated properly in the developer. Possibly too much agitation caused air bubbles to form in the developing solution.

[Louie Powell]

Clearly a film processing problem.

How are you processing your film.

[ic-racer]

You know how to take the mixing box out? It slides right out when you lift the front cover. Looks like someone spilled something on the diffuser plastic. Be careful not to scratch it when cleaning that off.

[harlekin]

It might be useful to compare to the previous print. This print is from the same negative, but the exposure time was a bit shorter. The streak was from the Orbital tank and I fixed that by doing a pre-soak before adding the developer (to get the paper to stick to the tray a bit.) The white spots are a bit different.
http://lh4.ggpht.com/_36bKpUBDfyo/S_IUGIAhWZI/AAAAAAAAAB4/f0Fb8YwOca4/s800/fallscreek01.jpg

[Gem Singer]

Chad,

Since the pictures are scans made from the actual prints, and the defects do not show up in the negatives, I would suspect something between the enlarger lamp and the paper on the easel.

Check the enlarger's lamp house and light mixing chambers carefully for dirt and cracks or defects on the glass surfaces. Also, check the enlarger lens for defects.

It is also possible, but not probable, that your printing paper is defective.

Try printing on a different batch of paper.

[harlekin]

There's definitely some gunk on the diffuser of the mixing chamber. I think it's some of the remnants of the old hardened foam seals that I replaced. I find it a bit odd that the spots changed between the prints, even though I don't think I touched anything but the easel and timer between the two prints. I'll give the lens a good close inspection though. The lens rotates a bit in its mounting due to the lens cone having a bit of an odd sized hole, so it could have moved slightly if I played with the aperture (I can't remember).

I think I'll try different paper sometime soon too. I wouldn't mind playing with some RC paper, as my fiber paper curls badly and I don't have a press.

[Andrew Tymon]

Chad, so your processing your prints in the patterson orbital? Could it be air bubbles attaching themselves to the print? I take it your darkroom is tiny(been there done that),you may not have room for regular photo trays,is there any other room that could be made light tight? When I lived in Louisisana I used to wait till night and block out the windows in the kitchen,cover the counters with thick plastic and print through the night. It wasn't ideal, but my only other options was a small closet with no air exchange. If you could setup something like this, you could watch your prints whilst they were developing and check all was going smoothly. As to the curly fibre try making some drying screens from fiberglass window screen.
Hope you solve this soon!
Andy

[Patrick Dixon]

I was having trouble with white lines across the top and bottom of the print, but narrowed that down to a development issue. (the fins on the lid of the Orbital tank.)

Out of interest what quantity of chemicals are you using in the Orbital? I've never seen anything like that with mine (4x5 negatives only), but I only use 100-150ml and I don't pre-soak. The only thing I've done to my Orbital is to score and roughen the base, but I have seen people cut the fins off completely.

[harlekin]

I use 100-150mL of chems in mine. I use it for both negs and prints. I went the epoxy route and have a grid of bumps, which lifts the print up a bit making the fins a bit more problematic. I may yet cut them off, but I didn't feel like performing surgery on my equipment in the middle of my processing. :) I figured the print stuck down pretty well by the end of processing, so a pre-soak would hold it down before I started the actual developing.

As for bubbles, I have observed a bit of air bubbles underneath negatives while I had a rinse going, but they move around plenty. I think the Orbital has severe enough agitation that stationary air bubbles aren't likely the problem.

I don't have another decent space to set up a darkroom. My darkroom is basically a coat closet underneath my neighbor's stairs, so it's hard enough just to use my enlarger (which is sitting on the floor).

I've been drying my prints in a blotter book lately, which is a huge improvement over hanging them as I did initially. I've had surprisingly good luck with a hair dryer for my test prints. If I flip the paper often and dry both sides at the same rate it doesn't curl as much. I still think that RC paper may be easier to start with if I want to mount any prints, but I've been playing with fiber paper because I'd like to try out hand-coloring once I get some decent prints.

[Patrick Dixon]

Ahh, yes the bumps will lift the print/negs and you might need a little more chemical volume than me too. I agree on the air bubbles, but I'd be reluctant to remove the fins as I imagine they'd help with the flow circulation. It's difficult to tell without a transparent version of the lid!

[ic-racer]

I guess I misread your OP. I thought you could see the spots get sharper in outline as you stopped down when projecting the image.

[harlekin]

You didn't misread it, I was mistaken. When I went back and looked at my notes, I apparently hadn't changed the aperture between those prints. I guess I just failed to clarify that. I made 4 prints trying to get my exposure figured out, so I had confused the changes from the previous print.