Wet Plate Collodion questions answered here.

[paulbarden]

I've been keeping my collodion in a refrigerator and not had a problem. When out in the field and temp is over 75 I keep an ice pack in the cooler bag that has my chemicals. So, what's a good commercially available collodion for negatives?


Kent in SD

Lea Formula 7 is good for negatives, but it ages quite quickly: plan to use it up within two months.
UVP 4 is good for negatives also, and being a two cadmium recipe, it’s very slow to age and with proper storage can remain usable for many months.
Also formulated by UV Photographics is a proprietary “house blend” called UVP-X. It uses 2 bromides and 2 iodides which makes for faster collodion (about 1 stop faster than most other recipes). It is also a very stable recipe, so you can expect it to remain usable for about a year if stored properly (cool, dark). I recently finished a bottle of UVP-X that was 18 months old and still worked well! (Though it had lost some speed).

To a degree, collodion recipes just aren’t that different when it comes to results. However, the following is generally true about salted collodion recipes: the iodides in a recipe contribute to contrast, and the bromides help create more middle values. Though it may seem counterintuitive to say, positives (tintypes) don’t need to be as contrasty as negatives. So a collodion recipe for producing good negatives will typically have more iodide than bromide. But I must say that in my experience, all but the most extremely contrasty scenes will produce a negative that’s fairly low in contrast regardless of which collodion recipe you use, in which case they benefit from some intensification or (better still) re-development to build density and contrast.

What you need to decide once you’ve made a negative is: what will it be used for? if you’re going to scan it for post-processing, or make a traditional silver gelatin darkroom contact print from it, then you may not need to intensify/redevelop the negative. I’ve found a property exposed negative with good contrast will print on a grade 2 or grade 3 paper. But if you intend on printing your negative on albumen or salt paper (or even platinum/palladium) then the extra density achieved by redevelopment or intensification is pretty much mandatory. How you choose to make a negative is going to depend on how you’re going to use it. This is where Quinn’s book is going to be very helpful to you.

Also bear in mind that there are so many variables in the process that no two people will have exactly the same results when seemingly using the exact same techniques. Your output is going to depend on 1) the state of your silver bath (it’s age, pH, silver content, etc.), 2) your choice of developer, 3) your water quality, 4) temperature and humidity on any given day, 5) your choice of collodion, and it’s age, and of course 6) your technical proficiency. That’s a lot of variables. So take what advice I offer as being just “general recommendations”. What works for me may not work for your circumstances. A certain amount of trial and error is going to be needed for each practitioner to find their sweet spot.

PS: I hope you haven’t been storing collodion in a fridge that’s also used for food! No matter how tightly capped, a collodion bottle still leaks Ether fumes which can be absorbed by food items.

[Tin Can]

Good suggestion. I am getting 4 cold packs a month with my eye drops

I've been keeping my collodion in a refrigerator and not had a problem. When out in the field and temp is over 75 I keep an ice pack in the cooler bag that has my chemicals. So, what's a good commercially available collodion for negatives?


Kent in SD

[Two23]

PS: I hope you haven’t been storing collodion in a fridge that’s also used for food! No matter how tightly capped, a collodion bottle still leaks Ether fumes which can be absorbed by food items.

No. Stored in a small dorm sized refrigerator. I only keep a very small quantity--the B&S kit. Ether/collodion kind of makes me nervous. Have heard only good things about UVP-X. Will wait until I use up what I have before ordering a bottle though. I'm trying to minimize on hands.


Kent in SD

[paulbarden]

No. Stored in a small dorm sized refrigerator. I only keep a very small quantity--the B&S kit. Ether/collodion kind of makes me nervous. Have heard only good things about UVP-X. Will wait until I use up what I have before ordering a bottle though. I'm trying to minimize on hands.


Kent in SD

Yeah, I try to limit how much Collodion/Ether I have on hand at any given time, too.


Seriously, I never store large amounts of Ether for long without either using it in a Collodion mix, or mixing 50/50 with Ethanol for long term storage. If you mix the Ether with Ethanol, it stabilizes the Ether and you no longer need to worry about creating explosive peroxides in your Ether. Its also very handy to have an Ether/Ethanol bottle available to add to a collodion that has become too viscous through evaporation of the solvents.

[iosef86]

Hi all! This is my first time on the forum, and i'm hoping for a little insight. I just set up a first attempt at a home wet plate collodion darkroom (first time using wet plate, but i have quite a bit of previous experience with other alt processes), and I'm having some trouble getting the right density in my images. Initially I thought it was an exposure issue, but even with more exposure the image is very thin. Does anyone have any input on what factors can help increase the density of the images?

I've attached my first two sample images below, both wet plate ambrotypes, shot on acrylic, with the backs blacked out.

Any input is appreciated, thank you!

[paulbarden]

Hi all! This is my first time on the forum, and i'm hoping for a little insight. I just set up a first attempt at a home wet plate collodion darkroom (first time using wet plate, but i have quite a bit of previous experience with other alt processes), and I'm having some trouble getting the right density in my images. Initially I thought it was an exposure issue, but even with more exposure the image is very thin. Does anyone have any input on what factors can help increase the density of the images?

I've attached my first two sample images below, both wet plate ambrotypes, shot on acrylic, with the backs blacked out.

Any input is appreciated, thank you!

Please provide details about how you are exposing these plates. Are you using strobes, or daylight? (If strobes, how much power are you using?) How are you estimating exposure? How long are you developing the plates, etc?

[iosef86]

Please provide details about how you are exposing these plates. Are you using strobes, or daylight? (If strobes, how much power are you using?) How are you estimating exposure? How long are you developing the plates, etc?

Thank you! They are both daylight exposed, new collodion and chemistry kit from Bostick and Sullivan, and they were exposed at f4.5, the one on the left for 3 seconds, the one on the right for 8 seconds. I used a light meter to judge the exposure (at an ISO of 3, it gave me a reading of 5.6 at 2 seconds - it wouldn't go down to ISO 2, and there's no stop on my meter for 4.5, so I compensated where I thought possible for the exposure) I used trays to process, as i'm waiting on delivery of sensitizer and fix tanks. They were developed for about 45 seconds each, washed and then fixed.

This is the chemistry set that I used: https://www.bostick-sullivan.com/cart/1077.html?category_id=440

[paulbarden]

Thank you! They are both daylight exposed, new collodion and chemistry kit from Bostick and Sullivan, and they were exposed at f4.5, the one on the left for 3 seconds, the one on the right for 8 seconds. I used a light meter to judge the exposure (at an ISO of 3, it gave me a reading of 5.6 at 2 seconds - it wouldn't go down to ISO 2, and there's no stop on my meter for 4.5, so I compensated where I thought possible for the exposure) I used trays to process, as i'm waiting on delivery of sensitizer and fix tanks. They were developed for about 45 seconds each, washed and then fixed.

This is the chemistry set that I used: https://www.bostick-sullivan.com/cart/1077.html?category_id=440

I'm familiar with the B&S kit. I am going to assume you've been sent Old Workhorse Collodion, which is an excellent recipe, but not always the fastest. I've had problems in the past with B&S selling me VERY well aged Collodion (too aged, IMO) which appears very dark yellow/orange or red in color, and at that point, it has lost a lot of speed and is in the 0.5 ASA range. Can you show me what color the collodion is?

If you make the assumption that the collodion is working at a speed of about 0.5 ASA, then you can be almost certain that you didn't give it enough exposure. It appears that you're using diffuse daylight, possibly through a window, facing north? Bear in mind that many modern windows use a glass that has a UV filter built in, so this can cut down the usable light by at least half. If possible, avoid making exposures with daylight coming through modern window glass, at least until you've determined whether they filter UV or not. Open shade outdoors is great.

The B&S developer is a good one: it allows new practitioners extra development time as they get acquainted with the process. (Traditional developer recipes allow for only 10-20 seconds time on the plate, which is trickier to learn to do well). 45 seconds is a reasonable amount of time on the plate. Avoid the temptation to extend the development time beyond 60 seconds when using the B&S developer, as it will start to give fog over the image.

Something else to consider, speaking of fog: it does appear there is some developer fogging over the images, and that makes me wonder about your chemistry temperature. Wet plate chemistry doesn't perform well when it gets warm! Ideally, you want to keep your chemistry under 75F (preferably 68F would be ideal). This is especially important for the developer! If the developer gets warm (80F or more) then you will certainly start to see undesirable development artifacts on the plate, like fogging and uneven streaks. I suspect there is some of that going on in the images you posted. So make an effort to keep your developer cooled to 70F as best you can, and you will get better results.

I suggest you abandon the light meter (totally useless when it comes to Collodion) and simply learn by testing exposure at the start of a session. You will quickly learn what the correct exposure is for the lighting situations you commonly use. Consider taking this approach: https://www.lundphotographics.com/in...st_plates.html
Essentially, this technique demonstrates how to make a test strip plate to determine what your exposure should be. It will save you a lot of time, materials and frustration: its the fastest way to finding your correct exposure time.

[iosef86]

Hmm, the collodion is a pretty dark yellow



It does certainly seem worth trying some test plates and increasing the exposure. I just didn't think that was the case because even with the exposure doubled, the image started to seem muddy and overexposed and the plate still seemed very thin. Also, definitely worth trying the next exposures outside instead of the window, I didn't think of the UV blockers.

And that makes sense with the developer as well, thank you! It does end up being pretty warm in my apartment, any tips on keeping the developer at an appropriate temperature? I've also heard that if the sensitizer is too acidic it can make for a weak image but I followed the directions to a T, and the test strip seemed to put it pretty squarely at a PH 4

[paulbarden]

Hmm, the collodion is a pretty dark yellow



It does certainly seem worth trying some test plates and increasing the exposure. I just didn't think that was the case because even with the exposure doubled, the image started to seem muddy and overexposed and the plate still seemed very thin. Also, definitely worth trying the next exposures outside instead of the window, I didn't think of the UV blockers.

And that makes sense with the developer as well, thank you! It does end up being pretty warm in my apartment, any tips on keeping the developer at an appropriate temperature? I've also heard that if the sensitizer is too acidic it can make for a weak image but I followed the directions to a T, and the test strip seemed to put it pretty squarely at a PH 4

I suspect your results so far are affected by a combination of all of the issues I mentioned: exposure, developer temperature and age of the collodion (yes, that is very well aged collodion you've got, and I doubt it has a speed much better than 0.5 ASA), and to less extent, the UV cutting effect of window glass. I look at your second plate and I don't think its overexposed at all - it just looks like chemical fog has obscured the actual image. I think you'll find you need 2X as much exposure as you used for the brighter plate. Make a test strip plate!

I strongly urge you to make at least one test strip plate to see how much exposure affects the outcome. You might be surprised by what you get. If nothing else, it will help you determine how much of a role exposure is playing in the results you got, and allow you to either tune the exposure better, or concentrate on other possible sources of error. I think you'll find that cooling the developer will make a significant difference: if the plates are fogging from an overactive developer (very likely) then you cannot see how close to correct your exposure is, if its hidden behind a fog of silver. So cool that developer: mix up a volume of developer that you expect is sufficient for a session's tests, and sit it in a cooling water bath. Add ice if you have to, and test the temperature. If you can keep the developer under 70F, that is ideal. (but not below 60F) You can also keep a bottle of chilled water in the fridge to have at the ready for mixing developer at the start of a session. (I do this) It can make it easier and faster to get set up for making plates. As an aside, I hope you are using the cleanest water you have available to you? If there is a lot of mineral content in your water, you may want to consider getting bottled water with low dissolved solids for your wet plate work, especially for mixing developer. (I use Reverse Osmosis water for mixing all my chemistry)

There are other troubleshooting tips I can recommend, but first things first - cool your developer and make a new test strip plate. Then we can go from there.

PS: do you have a GOOD manual yet? The B&S instructions are good, but barely more than adequate to get a person started. Do yourself a favor and get a good manual: Quinn Jacobson's Chemical Pictures, or John Coffers Doers Guide. Both are very thorough and easy to understand. (To get a copy of John Coffer's book, you have to write to him and send a check: he's "off the grid")