Finally, good wet plate results...

DonF

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I had been plagued by what I thought was very slow collodion or insufficient light from my 4800ws of Speedotron flash equipment. Image quality was good with few artifacts, but the images lacked intensity, with whites not being as bright as expected. Increasing exposure just blew out the light areas, but the intensity remained dim. Varying collodion age did little to help.

I have been using Bostick and Sullivan ferrous sulphate developer concentrate. They modified their instructions to recommend a 1:3 dilution of concentrate with a 45 second development time, changed from 1:1 at 15 seconds. I had been using 1:3. Yesterday I switched to 1:1 at 15 seconds. Amazingly, the intensity issue was gone. Without any trace of scum or overdevelopment, the whites "popped" and I found that my 4800ws of flash is more than enough. In fact, I had to move the lights back significantly to prevent over exposure.

For the last three images, I had accidentally left the optical slave dongle out of the socket on my second 2400ws Speedotron pack, so was shooting at 1/2 power. Results were so good I didn't notice until I found that the fill was missing.

I think the 1:3 dilution recommendation was a warm-weather precaution, but it did not work well for me.

Best,

Don

 

vdonovan

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Great! It must feel good to feel like you are getting control over this process.
 

Leigh B

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DonF said:
I think the 1:3 dilution recommendation was a warm-weather precaution, but it did not work well for me.
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I expect the 1:3 was done to give more development time, which could then be measured more accurately.

15 seconds is an awfully short period to control accurately with a manual process. One second = a 7% error.

The shots look quite good. Congrats.

- Leigh
 
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DonF

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Leigh B said:
I expect the 1:3 was done to give more development time, which could then be measured more accurately.
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Thanks. They came out nicely.

"Extended development time" was the reason B&S gave for the higher 1:3 dilution as well. The strange thing is that the development time scales with the dilution, but not the image intensity. That is, a 1:1 dilution seems to give the "classic" 15 second optimal development time for positives before scum and other bad stuff starts appearing. Likewise, tripling the dilution to 1:3 does triple the optimal development time from 15 to 45 seconds. Any longer starts producing scum and other overdevelopment artifacts.

The difference is in the image intensity that is reached with both dilutions at optimal development times. The 1:1 dilution gives much stronger images.

It seems the cost of more time to control the development is weaker images. With adequate safe light illumination, I have not found 15 seconds to be unmanageable with good pouring techniques.

Don
 

Leigh B

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DonF said:
It seems the cost of more time to control the development is weaker images.
Click to expand...
Hi Don,

Siince I have no personal experience with this process, my comments are based on processing modern films.

The amount of developing agent per unit volume depends critically on the dilution ratio, obviously.

It sounds like you're exhausting the developer in the denser areas of the negative with the 1:3 dilution.
This would argue for more aggressive agitation.

- Leigh
 
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DonF

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Leigh B said:
It sounds like you're exhausting the developer in the denser areas of the negative with the 1:3 dilution.
This would argue for more aggressive agitation.
Click to expand...

That make a lot of sense. The process calls for floating a small amount of developer (about 10ml-15ml for a 4x5 plate) over the surface without washing the developer and residual silver nitrate on the plate over the edges. Free silver nitrate is needed on the plate for proper development.

I have been agitating fairly aggressively, but the limited amount of ferrous sulfate in the developer may be exhausting before full development at the higher dilution.

Regards,

Don
 

Brickbird

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Don.......

Curious what your distance is from the light sources to the subject, considering that you made out like a bandit with only one 2400 w/s unit on those 3 images that you mentioned. Are you bouncing the 2400 from one side off an opposite reflector? Your portraits are looking great, BTW.
 
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DonF

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For the three where I was only at 2400ws, the distance was at 2 feet with an 11 inch reflector and no modifiers. I was at f/4.5.

For the others, I pulled both 2400ws lights back to 3 feet, same f/4.5.

Best,

Don
 

Brickbird

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DonF said:
For the three where I was only at 2400ws, the distance was at 2 feet with an 11 inch reflector and no modifiers. I was at f/4.5.

For the others, I pulled both 2400ws lights back to 3 feet, same f/4.5.

Best,

Don
Click to expand...
Well, that's good to know. Thanks for the reply. I've got 2 Blackline 2400's and one 4800. These are the older models without the white toggle switches and I went to turn on the 4800 several months ago and it blew up. They could have used it as a prop on the beach in Saving Private Ryan. So I'm down to the 2 2400's, so your post has been quite helpful.
 
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DonF

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I have one very old non-adjustable 2401A (with the neon lamps) and one variable output 2403B, along with three 102 flash heads with the 11 inch reflectors. I was careful to reform capacitors in the units before firing them by letting them idle for several hours. I was lucky and both are working to spec. I have seen the caps let loose in a 4800ws unit like yours. It was a memorable experience! Fortunately, the steel case kept the mess contained.

Just to complete the info on my pics, the ones in the first post were shot using 2-week old Bostick and Sullivan Old Workhorse collodion. I'd like another 4800ws, but the power I have now should be fine, especially since all the gear came in under $500.

Best,

Don
 
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DonF

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Here are a few from Friday with a new batch of collodion, age-reversed with a small amount of acetone. The reversal process needs a week or so and I only gave it a few days, so collodion speed was a bit slower. The results were still quite good with the stronger developer. I cheated on the last image and mirror-imaged in the scanner to correct the writing on the book.

Don

 

Leigh B

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Hi Don,

They look quite good. Congrats.

- Leigh
 

MattKing

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I particularly like the inclusion of books from the original Tom Swift series.
 
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