Your latest dag!

[Andy Stockton]

Interesting idea. It would be fairly simple to set up a test rig. Has there been any work done on the critical light frequencies for Becquerel? I will have to find something on what is passed by ruby/amberlith and find an LED with the right output. Of course then I would need a light-tight box to put it in and I would have lost my little red window for peeking at the development progress… Still, it would be much easier to make a battery powered device for hauling around in the car.

[Pobboravsky]

Rogues gallery of LEDs: http://www.oksolar.com/led/led_color_chart.htm

[Andy Stockton]

I am replying to this post in a new thread entitled LED based Becquerel development – so this one can get back on topic.

[Pobboravsky]

Andy,

Your light-tight box could be the plate holder which held the plate during exposure. To satisfy the plate-peeking urge put the darkslide back into the holder. cover the holder with ruby/amberlith and withdraw the darkslide. A very small box would enclose the holder + LED array. The rogues gallery list identifies some high output orange and red LEDs. (Or if you want to practice your mountain climbing skills you could shimmy up a traffic light pole and use the traffic light red LED array — yes, my silly gene just kicked in)

[Andy Stockton]

Silly works for me. 🙂  The traffic light may be the cheapest way to get an array.

 

[jgmotamedi]

Mina at 7200 w/s

 

I have been rather occupied with life and a blown motor on my fumehood. Anyhow, although it was not part of the “plan”, I was given a huge collection of Speedotron strobe heads, boxes, stands, et cetera. So, rather than cope with weak Oregon light, I decided to quickly check to see if there was enough power in the equipment to light a dag. Sure enough, 7200 w/s on one head was enough to expose a plate at f/2.8.

 

My daughter agreed to sit, although complained about the flash afterward. To make up for it, I allowed her to push the button while I sat in the chair. It wasn’t as bad as the descriptions I have heard of Jerry Spagnoli’s set-up–burned hair and all of that–but it does make a very loud POP and you see spots for a minute or so. I think Jerry told me he used 9600 w/s at f3.5, but I am not sure.

 

Anyhow, as you can see, the image is present, although this is probably one of the worst polishings I have done in a very long time–please don’t pay too much attention to that, nor the copper exposed in the corners! However, I would like to ask you all to look at the attached image and opine whether I am over-bromating or over-developing? Or both? Neither? Although you can’t see it on the scan, the plate is a bit weak and difficult to see. Your opinion counts! Thanks, as always.

 

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[greg7mdp]

Hi Jason,

Both bromine and development look good to me. I think the main thing to focus on is the polishing, and the results should be outstanding.

gregory

[jgmotamedi]

The polishing was a rough machine polish only; no hand buffing at all. Not my usual routine. So, as much as possible, please ignore the polish marks.

Although it does not show in the posted scan (you have view it at full resolution by downloading), the shadows are “misted” and the whole plate is weak. Normally I would guess that the misting is due to over-development, but perhaps the reason it is “weak” and difficult to see is because it is under-developed. Or am I second guessing myself?

[greg7mdp]

OK, I see the mercury frosting now. You’re probably right that you over-developped a little bit. I can’t say why the image is weak.

greg

[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.

[jgmotamedi]

I love the composition BTW.

Thanks for the compliment Andy, but composition with a 4 year old? Negotiation perhaps.

Anyhow the reciprocity question is a good one, there does not seem to be much on the other end (long) of the exposure spectrum, but that doesn’t mean that there isn’t on short exposures. For what ever it is worth, these exposures are comparatively long for strobes–around 1/400 of a second according to Speedotron.

[dagist]

Andy,

You wrote, “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)?” The answer to your question is no, it doesn’t matter.

In my experience, there is no noticeable reciprocity failure when using the short flash duration of a studio electronic flash unit. I meter the same whether I am shooting outdoors in bright sun or using flash in the studio.

The only qualification I need to make, is that my Balcar flash equipment does not have a super short flash duration at full power (they’re around 1/500th of a second) and I have not used flash equipment with a super-short flash duration like the Broncolor units offer, which can be as short as 1/12,000 of a second at a reduced power output.

Rob McElroy

Buffalo, NY

[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?

 

[jgmotamedi]

I will note for the record that I used a Speedotron 105 four cable head in a 22″ “Beauty Dish” reflector with a 4800w/s and a 2400w/s box. The rim of the reflector was about 32″ from subject, and was placed above and to the right of the camera.

I would love to hear about other people’s set-ups (Rob?), but am more concerned right now about my plate. Any comments on that?

[dagist]

Jason,

You are very fortunate to have a quad-head that can output up to 9600 watt-seconds of light as a single light source, which is then softened by increasing the diameter of the light to 22″ through the use of Speedotron’s Beauty Dish reflector. That is an ideal daguerreian light source, providing lots of power in a single source.

You may want to start a new DagForum topic, if the use of electronic flash with the daguerreotype is of interest to others.

Cheers,

Rob McElroy

Buffalo, NY

[jgmotamedi]

Right you are! I will create another topic.

[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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[corey r]

Well I’m back after a bit of a break. (the break was not of my choosing, i had to move and that meant breaking down the darkroom)

 

So yesterday was a busy, or maybe I should say ambitious day. Set up a temp darkroom tent in the yard at the new place with pvc, black plastic sheeting and a ton of duct tape. Shot two quarter-plate bdag portraits of a friend at 11 to check chemistry that came out surprisingly well and much faster than I had anticipated. Got my exposure time down to 2.5 minutes at f4.7 and was still a bit over exposed. The images came very strong in only about 7 minutes. I only let them develop for an hour so they have a pretty strong blue cast to them. I’m thinking that I can probably cut the exposure time in half and keep developing for a few hours longer next time. Took both plates through the wash stage and left them sealed up in a small plastic box until the evening.

Since both plates came out so well I decided to sensitize 4 more and head out to the Marin Headlands to try my hand at shooting away from the house. There was quite a haze cutting the available light by about 3 stops. Forgetting that the plates tend to get more sensitive the longer that they’ve been sensitized I over exposed by a good 2 or 3 stops when I compensated for the decrease in light.

So 3 hours of driving and shooting later i got back to the house, wiped the over exposed plates and decided to gild the two images from earlier in the day. Mixed the gilding solution wrong or maybe I dried the plates unevenly after the first wash but there is some chemical staining. Also couldn’t find my glass cutter until this morning so they sat unsealed for a good while. Now both have spots all over either from oxidizing or poor gilding, not sure. Either way its good to be back and remembering all the little things that can make or break the process.

 

Had a shoot scheduled for this morning to see if i could get everything right after yesterday’s lessons but the weather didn’t want to cooperate. Any way, here’s one of the two, you can see the serious chem spotting from the poor gilding job but something is better than nothing right? As always, sorry for the scratched glass.

 

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[corey r]

Here’s the other one. Both had the same problems. I think I know what needs fixing, just got too excited about running off to shoot in the field and didn’t see things through fully.

Oh these are b-dags fumed to the third yellow at about 5 minutes. Exposed for 2.5 mins at f4.7 (closer to f5.something with the bellows extension) with an EV of 14.9 @ ISO 100.

Suggestions are welcome. Wiping these and starting over tomorrow or the next day if the rain clears up.

 

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[Jon Lewis]

My daguerreotypy has been somewhat dormant the past year as going back to school full time takes really sucks up the time. It’s been about 15 months since my last ‘keeper’ but lo and behold I’m still doing some things right! The image itself is less than thrilling but the subject was chosen for convenience as a test for new plates using new copper and a whole new polishing routine. Though it is a somewhat quintessential depiction of Albuquerque.

 

Details: 6th plate with a 1/2 mil of silver plated on 20 gauge copper. Polishing was okay but not perfect, need to work on the final buff more. Sensitized with iodine to a second cycle red (slightly inconsistent from the middle to the edge) and exposed for 60 seconds at f/4.7. The light was 14.5 EV at ISO 100 and the conditions were bright with high clouds diffusing a bit of the light. It was developed for 8 hours under rubylith and a 200 watt light at a distance of about 6″. Fixed in Kodak rapid fix and gilded with Irving Pobboravsky’s formula.

 

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[Andy Stockton]

Glad to see you back in operation Jon

[Lionel TURBAN]

Last Dag from France.

 

Lionel Turban

 

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[fluidrive]

an 11″ x 14″ cropped by my scanner a bit.

 

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[Kaden Kratzer]

Quarter Plates

 

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[newone2010]

4X5 China made silvered plate

 

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[Author]

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