[Andy Stockton]

Glad to see you back in operation Jon

[Andy Stockton]

Generally contemporary daguerreotypes are made on a pure (.999 fine) silver surface. The base plate is usually copper. The silver layer is electroplated or Sheffield clad. The thickness of the silver varies with the process used, but 10 microns is common. A few practitioners work with pure silver plates.

The exact nature of historical plates may vary, but other members of the list would have to chime in on that as I have no expertise there. In most discussions I have read, the more pure the silver of the image layer, the better the daguerreotype, and that was as true in the past as it is today.

You will find various materials on the resources pages of this site that will lead you to further information. Good luck with your study.

[Andy Stockton]

It is very clear and helpful. Your explanation made it it easier for me to understand why Becquerel Daguerreotypes look different from mercury developed ones. I didn’t understand that before.

[Andy Stockton]

Congratulations Chad. The first one is a great feeling. Great new section of your website, I look forward to hearing from you as next steps unfold.

[Andy Stockton]

Hi Ron-

That statement just refers to the possibility of glass breakage.

When I first started I was very concerned that the silver would eventually peel off the glass because I saw how fragile the bond was during wet processing. Various conversations I have had now lead me to believe that if you get the silver layer successfully through the wet processing steps intact, there is no reason it won’t last a very long time. This assumes of course that you adequately seal the daguerreotype in the current manner for protecting all silver metal based images.

Good luck on your working with brass. Be sure to write up some of the things that you learn and post them to CDags. It benefits us all.

Andy

[Andy Stockton]

You are welcome, I hope the paper triggers a number of interesting experiments. And thanks for posting the image. As you know I ran across it early in my investigation of glass daguerreotypes. Once I got over my disappointment at not having invented the medium 🙂  it was one of the forces that inspired me to keep going. I find it quite hauntingly beautiful.

 

[Andy Stockton]

I did some reading on the issue a while back and had trouble finding much discussion of specifics.

This source: http://www.atsdr.cdc.gov/cabs/mercury/

Included this:

Tests are available to determine mercury exposure. The particular test depends on type of mercury to which a person believes he or she has been exposed.

Test: Urine mercury

Procedure:

Urine specimen is taken to a laboratory for analysis. This test is good for detecting exposure only to elemental or inorganic mercury, not methylmercury.

Test: Hair mercury

Procedure:

Hair is only considered a reliable marker of exposure to methylmercury or ethylmercury.

Test:Blood mercury

Procedure:

Blood is an excellent indicator of exposure to methylmecury only.

Acute elemental exposures can be detected for a few days in blood. Otherwise, after 2 days, urine is a better indicator of past or cumulative elemental mercury exposure.

It would seem that for our purposes, urine testing is best unless you have a recent high level exposure concern.

This source had some information as well.

http://www.osha.gov/SLTC/healthguidelines/mercuryvapor/recognition.html

[Andy Stockton]

Thanks, it was a great deal of fun to do. I hope you will report on your experiments. There are numerous questions still to answer and sharing our attempts will help.

 

As far as silver thickness in concerned Mike King from Angel Gilding estimates the dual layer method of chemical deposition to produce a maximum thickness of about 100 nm. Based on Irv Pobboravsky’s work on the thickness of the iodide layer required for daguerreotypes, that would seem to be enough.

 

I am very interested in the results others have in producing larger plates and comparing them to more traditionally made plates. The writeup is based on only a few very small samples (10 total) and I have no significant body of traditional work to compare with the glass versions. I like the look of what I did produce, but will be interested in hearing others make comparisons who have more experience than I do (that is to say almost everyone). 🙂

 

[Andy Stockton]

Congratulations on the new family member. Have you taken a daguerreotype of him/her yet?

Re photographing dags, I believe that a polarizer would help as well, and some people even put polarizing material over the light sources in conjunction with the lens polarizer. I haven’t done that however so can’t comment as to details. Anyone willing to share more details?

[Andy Stockton]

Hi David. How about sharing a few more details of your scanning process? Are you scanning in the frame? Or are your daguerreotypes directly on the glass? With or without the cover glass? What type of scanner and what are the settings you are using?

When I made my own first scans last year I was using an all-in-one printer/scanner/fax and it turned out not to have enough depth of field. I could see the image, but it was not in focus. Switching to a higher quality scanner and working with the cover glass removed made the difference for me. Your problem may be different.

[Andy Stockton]

Etsy is great. I have found all sorts of interesting art related supplies there.

[Andy Stockton]

There are lots of web based hardware sources. Post a picture of your hinge, maybe someone will have a suggestion. I don’t do restoration work, but I would guess that the hardest part would be finding an exact match with your old hinge. It might be easier to buy two modern hinges with the correct dimensions.

 

Here is a tiny 1/2″ x 3/8″ brass hinge from Whittmore-Durgin Stained Glass Co.

 

Anyone else have an idea?

 

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[Andy Stockton]

I will enter a submission. It is exciting that the space may have general public traffic, a great opportunity to show contemporary daguerreotypes more widely. Perhaps there could be some way of highlighting the exhibit for symposium attendees as Rob suggests. This would be particularly true if any of the entrants are interested in selling their works to Daguerreian Society members, since they will not be able to be on display in the regular symposium selling area.

[Andy Stockton]

Drdag – if you were trying to do what Chriso has been doing, solder a thin silver plate to a thicker brass or copper substrate, what technique(s) would you use? It seems like an interesting approach to getting a sturdy, multi-use plate that still might be somewhat less expensive than the pure silver plates you have used to good effect in your work.

[Andy Stockton]

Hey Chriso – I was looking at your Dags on photobucket and wondered about the plates too. Are you putting .999 thin silver on brass and soldering it? Do you do that with a torch or in a kiln of some kind? Just curious – if it’s a personal trade secret, never mind.

[Andy Stockton]

Here is my latest effort, a portrait of my wife Sarah. This was taken with I2 fuming 23 Sec to golden yellow, 10 Sec exposure @ f1.7 EV 14.5 @ ISO 100, Becquerel development for two hours. Overall I like it, the main defect is that the highlights on the cheekbones are slightly blown. It is also still fairly blue in tone.

 

This plate as with the two previous posts was taken on silvered glass. I will be posting a paper on my methods fairly soon on CDags.org. I have written it up, but need to get permission to use some images first from other artists that are included in the paper.

 

 

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[Andy Stockton]

Interesting approach, sounds like it would be a more controlled heat source than a torch or alcohol lamp. Have you had a spill of gilding solution onto the lamp housing? If so, what happened?

Also, what is your method of leveling the plate so the meniscus is even?

I will have to check the temperature that my lamp housing reaches.

[Andy Stockton]

What was the distance between the array and the surface of the plate? When I have examined different LEDs the lens design had a big effect on the shape and intensity of the light beam. I was worried that I might get a disconnected pattern of circles of strong development surrounded by weaker areas. Did you increase the distance to avoid “spots”?

What interests me about this approach especially (besides no fan and lower power consumption) is the idea of creating a developer that could run on my car battery. I someday aspire to take images somewhere besides my back yard, and being able to start a controlled development cycle while the latent image is still fresh seems a good thing.

[Andy Stockton]

Wow. That Quad head is quite the piece of equipment. I have nothing meaningful to add to the technical side of this discussion, but I am going to start watching Craig’s list for studios going out of business! 🙂

 

I do have a plan for using my puny off-brand strobe heads to take an indoor still-life by using multiple flash pops, but that is waiting on my understanding better how to translate the multi-flash reading on my light meter. I have just been using the meter’s EV scale and an exposure cheat sheet derived from Jonathan Danforth’s work for my previous exposures. The multi-pop gives a standard reading of speed/f-stop.

 

[Andy Stockton]

I guess what I mean then is I love your daughter’s composition. It has four year old written all over it. 🙂

 

I’m enjoying the conversation about strobes as well – not much information out there on that topic that I have seen. Anyone have any other thoughts on Jason’s report of the image being weak?

 

[Andy Stockton]

I’m too inexperienced to answer your question Jason, but I wonder – is the time response of the sensitized layer linear? Does it matter if it receives its “dose of light energy” in a very short period of time (strobe) as opposed to a longer one (sunshine)? I am familiar with the concept of reciprocity failure, but only in the “overly long exposure of film” part of the discussion.

Does anyone who has used strobes have any comment?

Re the mercury frosting (which is clearly visible in the larger image)three different sources I have read link that to over development.

I love the composition BTW.

[Andy Stockton]

AC in the US is always 60 Hz and the polarity is not a problem the way it is with direct current. It will still work if you reverse the wiring (but also won’t change anything). You may just have gotten a defective bulb. It sounds like the halogens are not reaching ionizing temperature.

Do be sure not to touch the bulb. Depending on the case type finger oils can cause them to shatter when hot. How cold is your shop? I would let it run at least 30 minutes before you give up on it. I would throw a few tape layers over the photocell too.

[Andy Stockton]

Sometimes they take 5-10 minutes to start. Just leave it on a while.

[Andy Stockton]

Irv – is there already anything published on the wavelengths that produce the Becquerel development response? Creating an LED developer seems very do-able, it is just a matter of deciding which LED type to try first. Knowing the specific wavelengths would make that easier – if there are multiple peaks it might even be a good idea to mix more than one color into the array as long as the plate-to-array distance was such that full overlap of colors occurred.

[Andy Stockton]

There was a forum on the site that Jon Lewis posted that said the highflux LEDs get pretty hot. If you have used them at work have you noticed that issue? I thought LED’s were not supposed to do that – maybe the other components in the module?

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