Wet Plate Collodion questions answered here.

[pau3]

I have recently rediscovered this wonderful thread. Let me start by thanking all the people that has contributed here.

I think, however, that the use of glycerin to postpone fixing or washing when working in the field has not yet been covered.
I have read a few things around the web, and I have tried some, but I am not completely sure if I'm doing
things correctly or if I could do other things.

In the last few days I've been doing the following. After exposing the plate, I develop it and give it a quick rinse.
Then I flow the plate with a mixture of equal parts of glycerin and distilled water. I leave the liquid on top of the plate
for a couple of minutes, drain it and finally I place the plate horizontally in a black box(*). Next day, once at home,
I wash the plate(s) and fix them. Usually, I also redevelop them. This procedure seems to work fine.
The only drawback is that, since the plates are only developed and not fixed and I don't have enough experience yet
to judge the exposition from the unfixed plates, I often find that the plates could have benefited from a longer exposure.

Then, my questions are the following.

1) Is the procedure, described above, correct? In particular, I am not sure if only flowing the plate with glycerin is the right
thing to do. It seems to work, though.

2) Could I develop, fix and, after a quick rinse, flow the plate with the above procedure? In this way, at least I could better
judge the exposition and leave the rest of the steps (final rinse and intensification) to the next day.

I have found that fixing and washing plates in the field is rather impractical.

3) Has anyone compared two identically exposed and developed plates, one of them fixed in the usual manner and the other
one flowed with glycerin and fixed the next day? Are they identical or the arrested fixing has some effect on the result?
I will do the test next week, but maybe someone has already done it.

(*) The black box is a dedicated box, light tight, designed to store plates horizontally.

[cuypers1807]

I just carry a rack that fits in a tank of water and fix on site so I know I exposed the plate correctly.

[pau3]

This is a follow-up of my previous post on the use of glycerin to postpone fixing/washing of plates
when working in the field. I am interested in the method because I want to shoot negatives and I prefer
to do the intensificatioin step in a more controlable environment, besides the saving in water and hardware
that one needs to carry to the field.

I have performed the following test. I shot three identical plates, in the sense that they were given the same exposure
and were developed during the same amount of time. The plates had albumenized edges. I must say that
my skills are not goog enough to obtain three really identical plates.

The first plate was developed, fixed and, after a quick rinse, flowed with 50% glycerin. Finally, it was stored in a dark box.

The second plate was developed, rinsed and, without fixing, flowed with glycerin. It also went to the dark box.

The third plate was fully processed, with a final intensification with iodine/ferrous sulfate.

After 36 hours, I processed the first and second plates, giving them the same intensification as the third one.

Finally, I varnished all three plates with sandarac varnish.

Besides the differences due to pouring errors, all three plates seem to be identical. To be sure, I will print them as soon as
I get back to my darkroom, but I'm quite confident that the method works.

This is the tintype I shot to assess the exposure of three plates:



La Taiadella, Catalunya. Agost 2023. by Pau Martín, on Flickr

[Eric in Vegas]

I bought some pre-cut standard 5x7 trophy plates for my Zebra v2 5x7 holder. The fit is so tight that I have to sort of force the plate into the holder and its difficult to get them out. I suspect this will cause problems when I attempt my first wet plates. I'm guessing that I need to have my plates trimmed a tad smaller...maybe 1/16" so that there is a tiny bit of play? Is it typical to have to make tiny adjustments to the plates, perhaps using a file?

[Eric in Vegas]

I took my first tintypes today and my images all seem to come out dark (this image has also been varnished). I kept increasing exposure so I don't believe underexposure is the cause but the sun may have been outpacing my exposure adjustments. Could this be an under or over development issue?

Also, most of my images had a slight bit of fog but not over the entire image but rather like foggy artifacts. Interestingly enough, when I was cleaning some of my plates to reuse them, I found that these artifacts wiped away with a wet finger. I wouldn't think this would be good for the emulsion...has anyone encountered this, and if so, any ideas on how to prevent this?

[paulbarden]

I took my first tintypes today and my images all seem to come out dark (this image has also been varnished). I kept increasing exposure so I don't believe underexposure is the cause but the sun may have been outpacing my exposure adjustments. Could this be an under or over development issue?

Also, most of my images had a slight bit of fog but not over the entire image but rather like foggy artifacts. Interestingly enough, when I was cleaning some of my plates to reuse them, I found that these artifacts wiped away with a wet finger. I wouldn't think this would be good for the emulsion...has anyone encountered this, and if so, any ideas on how to prevent this?

So, I'd need to know more about your materials and methods before I could give you advice: what chemistry are you using, how old is it, which collodion, which developer, etc? How long are you developing the plates?
Yes, it's possible that the light intensity was dropping as you made each plate, but it's hard to say without knowing specifics: by how much did you increase exposure each time?
RE foggy artifacts: this is likely what is called "oyster marks" which is exposed silver from a previous exposure being redeposited on the next plate, leaving marks around the plate edges. Yes, it can be wiped off gently with a cotton ball when the plate is in the wash water. Most of us have to do some degree of cleanup in this manner. The way to limit how much of this you get is to clean the plate holder after every single plate - use a Q-tip to wipe any leftover silver nitrate out of the plate holder before inserting the next plate for exposure. This will eliminate 90% of the contaminated silver marks.

[ethics_gradient]

I took my first tintypes today and my images all seem to come out dark (this image has also been varnished). I kept increasing exposure so I don't believe underexposure is the cause but the sun may have been outpacing my exposure adjustments. Could this be an under or over development issue?

Also, most of my images had a slight bit of fog but not over the entire image but rather like foggy artifacts. Interestingly enough, when I was cleaning some of my plates to reuse them, I found that these artifacts wiped away with a wet finger. I wouldn't think this would be good for the emulsion...has anyone encountered this, and if so, any ideas on how to prevent this?

You lose about a stop or so of brightness under varnish - basically the wet plate in the fix is around what it'll look like after varnishing, but it brightens up a bit when it dries in between. I always scan plates when they're dry, they tend to look quite dull after varnishing.

The best way to get a good exposure is to do a test plate and keep your development time consistent; I see way too many people trying to both change exposure in camera and then develop by inspection and wondering why they can't get good results. I use Waldack's No.1 developer and 15s or so development time is normal.

If you use a spot meter to record EV values in your metered scene with the test plate, you can then adjust your exposure as the light changes (within reason, the "golden hour" is usually a crapshoot for collodion and I often switch to a film camera if I have one on me). Since collodion ages it's generally considered best practice to do a test plate at the start of each day, you can probably get away with not doing it but it's cheap insurance IMO.

With the oyster shells, while it's under water/fix, use a cotton ball and basically no pressure rather than a finger for wiping it away. The better you clean your plate holder, the fewer problems with these you should have.

If you're getting splashy looking marks around the edges that won't wipe off, it's probably from contaminents (silver nitrate and developer) on your gloves - either change them or wipe them off with alcohol between plates.

I bought some pre-cut standard 5x7 trophy plates for my Zebra v2 5x7 holder. The fit is so tight that I have to sort of force the plate into the holder and its difficult to get them out. I suspect this will cause problems when I attempt my first wet plates. I'm guessing that I need to have my plates trimmed a tad smaller...maybe 1/16" so that there is a tiny bit of play? Is it typical to have to make tiny adjustments to the plates, perhaps using a file?

Yes, better slightly too small than slightly too big. It shouldn't normally happen, but plate holders do vary in size (the Charmonix ones I use for 4x5 and 8x10 are just a tiny bit smaller than standard) so if you're buying from a supplier it's worth confirming measurements in advance.

I ordered some tin plates that were slightly too big and used tin snips to trim the excess off. Leaves a ragged edge so I only use them for test plates. I also have a bunch of glass I bought from another photographer that is also slightly too big for the Charmonix holders, will use inserts to shoot them in my 8x10 camera.

[QUOTE=pau3;1689219]This is a follow-up of my previous post on the use of glycerin to postpone fixing/washing of plates
when working in the field.

Great work! I have been using the glycerine method for shooting in the field since I started, works a treat. I always fix in the field with hypo or ammonium thiosulfate because I find the feedback is important and lets me adjust if needed. After fixing I rinse with a very small amount of water (~200mls, mostly on the image side but also a bit on the back to get any fix off there) then coat with glycerine. They will last weeks and even months like that before doing the final rinse and varnish.

[Eric in Vegas]

So, I'd need to know more about your materials and methods before I could give you advice: what chemistry are you using, how old is it, which collodion, which developer, etc? How long are you developing the plates?
Yes, it's possible that the light intensity was dropping as you made each plate, but it's hard to say without knowing specifics: by how much did you increase exposure each time?
RE foggy artifacts: this is likely what is called "oyster marks" which is exposed silver from a previous exposure being redeposited on the next plate, leaving marks around the plate edges. Yes, it can be wiped off gently with a cotton ball when the plate is in the wash water. Most of us have to do some degree of cleanup in this manner. The way to limit how much of this you get is to clean the plate holder after every single plate - use a Q-tip to wipe any leftover silver nitrate out of the plate holder before inserting the next plate for exposure. This will eliminate 90% of the contaminated silver marks.

Thank you for the tips. Yesterday was my first time ever shooting wet plate and I was using a brand new starter kit from UVphotographics (UVP-4 & Iron Potassium Nitrate). Today I adjusted my exposure and saw a huge difference...I think running a bit overexposed now but at least moving in the right direction. I adjusted how I was applying my developer and the little "wispy" cloudy areas disappeared. I'm not sure if that was it, but I was applying in a circular motion and I felt like the cloudy areas were kind of mirroring the motion of my developer application? Now I try to quickly apply from one edge and cascade it across.

My collodion pouring technique is sorely lacking and my development needs work but I'm finally getting some brighter images.

[Eric in Vegas]

After extending my exposure, I'm looking like this now (varnish applied). My collodion pouring needs some work. I think I'm on the right track but any tips/advice would be greatly appreciated.

[ethics_gradient]

I adjusted how I was applying my developer and the little "wispy" cloudy areas disappeared. I'm not sure if that was it, but I was applying in a circular motion and I felt like the cloudy areas were kind of mirroring the motion of my developer application? Now I try to quickly apply from one edge and cascade it across.

It sounds like you're doing it right, Borut Peterlin has a video or two on YT where he demonstrates the technique. Developing is much more tricky than the collodion pour (see below), uneven development can result from insufficient agitation or the collodion not being runny enough (can dilute with more alcohol to help it flow better).

After extending my exposure, I'm looking like this now (varnish applied). My collodion pouring needs some work. I think I'm on the right track but any tips/advice would be greatly appreciated.

Pour until the puddle is about 3/4 of the way out to the edges before you stop and start tilting it to each corner.

I started wet plate back in Australia where collodion is comparatively expensive (100mls for AUD$65) and it took me way too long to stop being too stingy with my pours. In the end I had to realise that saving a few mLs of collodion to make a bad plate is a false economy, and with technique you can recapture most of the overage in your pour-off bottle anyways.