Processing Error or Emulsion Problem?

I just got back another mini-batch of Lane dry plates from processing at Blue Moon. Camera was a Chamonix 045n, lens was a 5 inc. Derogy Petzval c.1858. I scanned the three images and have some observations:

1. Since turning the rear most element around focus seems much sharper.
2. My exposures are now spot-on.
3. Petzval + plate is giving me the vintage look I want.
4. There are a lot of swirly marks on the plates that keep them from perfection.

These swirly marks appear to have been made by water being allowed to dry on the plates. All three plates have them. The plates Blue Moon processed for me in the last two batches did not have this. I'm wondering if the swirls are due to a mistake at the lab, or if the plates got too warm sitting on my front porch for several hours where the postman left them? Temperature was in the mid 80s F (30 C). I opened the shipping box and put the plates into the refrigerator when I got home. Not sure if the exposure to the heat caused the swirls, or bad processing. Any ideas? See below.

1. Young Princess. I had my camera at our local park & waterfall and saw a family taking photos of this very cute little girl. I asked if I could take a photo also, and they graciously agreed.

2. Legendary Mike. He's a photographer with a studio in a small nearby town. He was all eager to be a test rabbit for me!

3. Sioux Falls, in flood. The Derogy Petzval delivers again.


So, any thoughts? I do want to start doing my own processing, but don't have time just yet. What do you think caused the swirls?


Kent in SD

If I remember right wasnt there a few batches with that problem due to emulsion application problems early on? Contact Lane and have a talk, Im sure it will be worth your time.

Quote:

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Originally Posted by Gary Beasley

If I remember right wasnt there a few batches with that problem due to emulsion application problems early on? Contact Lane and have a talk, Im sure it will be worth your time.

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Hmm. This was from my first box, I believe. There weren't notches on the edge. Funny the others in the box seemed OK.


Kent in SD

Check your batch # on the back of the box. Swirlies were showing up early on until I discovered the cause around batch 8. Not all the time, but often enough that I needed to troubleshoot. It was essentially a side effect of scaling up the emulsion batch size without adjustments from the amounts I made for my own use to larger quantities. Making adjustments to the “recipe” and tweaking the glass prep process eliminated the swirlies (there are a lot of sleepless nights behind that statement).

If you’re on facebook, the Dry Plate Photographers group has a thread there from several months ago (March, I think?) where we were troubleshooting the cause.

So I don’t think that was anything Blue Moon was doing. I went through the processing of plates with them in detail, and gave them plenty of plates to practice with (they get samples of experimental emulsions from time-to-time as well). They are good people and know their stuff. I use them for processing film when I need to.

By the way, Stearman Press now has 9x12 holders available for their SP-445 daylight developing tank, so you wouldn’t need a darkroom to develop them if you wanted to process them yourself.

Quote:

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Originally Posted by Nodda Duma

1.Check your batch # on the back of the box. Swirlies were showing up early on until I discovered the cause around batch 8.

2. By the way, Stearman Press now has 9x12 holders available for their SP-445 daylight developing tank, so you wouldn’t need a darkroom to develop them if you wanted to process them yourself.

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1. It's an older all white box and says "Batch No. 8." Geepers, do I have to just throw them out?

2. I'm shooting 4x5, just got some 6.5x9 (seem to fit my c.1930 Voigtlander holders OK,) and hope to start shooting 5x7 this fall. I was planning on starting processing using tray developing, one at a time. Got to thinking this would take a long time since I often shoot 4 at a time. The Stearman tank won't scratch the plates? Hopefully it's not too complicated.


Kent in SD

Stearman tank works great. I use it exclusively now. It also develops sheet film great.



How many of the No. 8 batch plates do you have left? Send them back and I’ll replace them.