Becquerel Color Cycles?

[RichardCynan]

Can anyone recommend a colour cycle for Becquerel Daguerreotypes? Reading both Charlie Schreiner’s guide (Newdags.com) and "Becquerel in a New Light," by Gerard Meegan has left me a little bit confused.
Schreiner recommends using the first/second cycle colours and Meegan prefers third cycle yellow/green with longer development. Both methods must work well – just a little unsure about which one to pick.

I’d be interested in learning what colors all you modern Daggers prefer using (or at least know to work).

[CasedImage]

Hi Richard, when I first started making becquerel I tried the thick Iodine coatings of more than one color cycle and with not much success towards getting decent images. I found my best results for Becquerel came from taking the Iodine coating color to first cycle to a red with tinges of purple. My development times were ranged from 1-3 hours. I built a developing frame that kept the light out but left the back of the plate exposed, so that sitting in the sun developing, the plate could cool rather than heat up and fog the plate. Trial and much error is the only sure fire way to find out what works for best you though.

www.CasedImage.com

[photolytic]

Before Gerald Megan or Charlie Schreiner, Irving Pobboravsky did his definitive Study of Iodized Daguerreotype Plates in 1971. His report is not available on line but well worth reading if you can find a copy.

He studied the sensitivity of iodized silver plates through 3 color cycles using both Becquerel and mercury development.

On page 45 of his book he lists the relative Becquerel speeds of iodized coatings ranging in thickness from 15 to180 nanometers. Pobboravsky’s Becquerel plates were developed under a 500 watt 3200K lamp at a distance of 30 cm for only 20 min.

He reports that the maximum speed was for Becquerel plates with a 30nm yellow coating was ISO 0.0008. or “60 seconds at f/4.5 on a bright sunny day.

Plates with coatings thicker than 80-90nm (2nd yellow) up to 180nm (3rd yellow) showed no image after 20 minutes and were assigned a relative speeds of Zero. Subsequent Becquerel workers have successfully employed longer development times to develop more heavily coated plates.

[CasedImage]

Definitive indeed but yes also hard to find a copy of. I feel the great gulf and divide between me noting in my field notebook that a plate that was sensitized to "red/purple" and exposed at 40 secs came out looking ok and Irv documenting his iodine thickness in nanometers… I am also reminded that when he did that I was one year old..
For someone started out with the process though I would say there’s enough to tackle with out jumping in at the deep end of heavy iodine coatings. Those long development times abate trial and error learning as by the time you’ve learnt you error of the morning, the sun has gone and it is time to go to bed and sleep on it. Gerald Meegans article is a good read though and I will see about getting a copy for the resources page, I imagine everyone would like to see Irv’s study there too.

www.CasedImage.com

[botticelli1972]

I have tried both long and short iodine cycles and have found, personally, that I like the first series colors the best. I found the second and longer iodine series to make muddy images and the exposure times are very long, in the 20 min @ f 4.5 in full sun range. I use first series colors exclusively now. In my fuming box it takes usually between 90 seconds and three min to get a good color, depending on the temperature of my dark room, which is unheated and with no A/C. In the winter it has taken as long as 10 min. I am not so picky about the color, after 90 seconds I check every 30 seconds and pull it when it has gone past orange. Sometimes the plate takes iodine faster and the color goes in the purple/blue range and I do not worry about it. They all make good images and the variety of resulting tones are pleasing, keeps it interesting as to how it will come out.

For developing I have found for my plates, using a Kodak Print Projection Scale to determine timing, that full development takes place at 45-50 min. in full sun under amberlith. The image begins to show quickly in less than 5 min. Sometimes I have even noticed self developing highlights that appeared while still in camera. Any less than 45-50 min. and the image is not fully realized and any more and it begins to fog, it is a very fine line. Others have reported having much different results. Get yourself one of these translucent projection scales and try for yourself. Do not buy the new ones as the are low quality machine printed, find an old one on eBay which is a developed piece of film with subtle graduations. -Larry

[RichardCynan]

Thanks for the advice. I’ll start with the first colour cycles and see where they get me.
First cycle magenta seems quite popular.

[drdag]

The info that Larry has given you is going to save you ages, I spent 3 months and 200 attempts before I got it.
You do however need to do quite a few until you get a feel for it ,which I believe is the best way. I think that there are too many variables in the preparation to exposure to be able to be too scientific as you can with control iso film.
There is no subsitute for experience and the rewards are very satisfying, Brenton

[RichardCynan]

I didn’t think this process would be a walk in the park… but 200 attempts! Now I see the benefits of using solid silver sheets; well worth the cost in the long run. Don’t think I’ll need to mix my precious gilding solution anytime soon. ” title=”Wink” />

Thanks again for pointing me in the right direction.

Now, time time to get cracking!

[robindreyer]

I learned most of what I know about daguerreotypes from Jerry Spagnoli, who has probably taught more Becquerel workshops than anyone else. For years, he’s recommended sensitizing to the first cycle magenta. But I talked to him recently and he said that lately he’d been having his workshop students sensitize to straw yellow in the first cycle and this seemed to be resulting in a lot less fog with no loss of tonality or speed.

Robin

[botticelli1972]

I also have recently been switching from a magenta to a slightly earlier deep yellow/orange. I have found the magenta to produce a light blue image with grayish whites and good total range while the earlier yellows produce a more black and white look with a touch of sepia/brown tonality but less total range. Both are nice too look at and I have been just timing the colors, about 3 min in my box, instead of inspecting and enjoying what ever develops out.-Larry

[corey r]

ok, here’s a question for any of you: when you refer to first cycle yellow, are you referring to the yellow that comes up immediately after you place your plate into the camera or the yellow after the first green? i’ve been having some success shooting bones and well powdered, very patient models using the yellow after the second green (its a really strong green) and developing times in the 4-5 hour range.

I would like to attempt some shots with a faster exposure time so my portrait models don’t get so worn out just trying to sit still and it sounds like a thinner coating would do the trick.

thanks again for your input,

corey

[botticelli1972]

corey, I am always trying something new, the color I have been using of late is first cycle deep orange/magenta, In my particular box it takes about 2:15 to get to that color depending on temperature in the dark room (keep a chart it will help with consistency). My average base exposure for a subject with no bright white or blue in it is 20 seconds at F/2.9 in full sun, 10 seconds for a white or blue subject. Second series colors are slower and tend to look “muddy” in my opinion. Lately I have been developing for 2-3 hours in a southern window, but beware of heat which will cause fog. Larry

[Gmeegan]

For any clarification or assistance with extended development Becquerel development I am still alive and well, living in Thailand. I just do not care to much for forums and I purposely remain “faceless”. If you are sincere, we can figure out how to make contact mere directly through email or some other way.

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