What do people use for indoor lighting?

[RonF]

I am making daguerreotypes using the becquerel process. I have been primarily doing indoor photos. I tried using a fluorescent black light and that worked ok. Then I discovered that a compact fluorescent spotlight of the “daylight” type works better. (I can give more specifics on that if anyone is interested). But in terms of getting more intense light and getting my exposure time down, I feel that there must be something better.

I would like to know what other types of lights might be good. Particularly if there is something that gives a lot of the right frequency of light for becquerel that is not too expensive. I suppose I could spend $100 on a halide utility light, but I would like to know that it is going to be effective before I invest in one.

[jdanforth]

If available light won’t cut it, I resort to those big halogen lights that you can buy at the big-box hardware stores here. I also have a big studio floodlight that I use sparingly. The lamps are $40!!

[RonF]

Rereading my post, I just realized I may not have been clear about one thing: I am looking for a light source to illuminate the subject for the exposure. For the development I am all set (I use a halogen).

Jonathan- I think you knew that when you posted the reply, but I am not sure. I thought that a halogen would not put out a lot of UVA and I thought that UVA was what I needed for the exposure.

[jgmotamedi]

I built two sets of lights using four (eight total) Phillips florescent 55W 5500K florescent bulbs (the same ones which some of the more expensive photo lights like Gyoury use) which put out a decent amount of UV from an aquarium supply. I could have used 10,000K “black light” bulbs, but I also use these for copy work. Another option would be to buy two or three 750watt metal halide bulbs, ballasts, and reflectors from an “indoor garden” store. These are not terribly expensive and should put out lots of UV.

In an aside a few weeks ago I stripped some parts off a high end 20×24 graphic arts camera which was on its way to the dump. It had an interesting light system which I salvaged but have not yet tried. It uses four 1500 watt pulsed Xenon lights which should put out LOTS of UV light, but may actually be dangerous.

[Andy Stockton]

Is there already a source that defines in detail the spectral response of Becquerel and Mercury daguerreotypes? That would be useful in picking a supplemental light source. Also – for those of you using alternate light sources, are there any safety precautions that should be observed? Do you limit the time a person is exposed to your lights, or caution them not to look directly at the source?

[CasedImage]

When I sat for a triptych portrait for Jerry Spagnoli, the lighting set up blew me away… almost literally! He had a huge lighting set up, many high voltage devices coupled together that probably made the lights dim in the rest of the building on west 25th street. With all this lighting the exposure was a fraction of a second (dags with shutters, who’d thought!) and it was a that point that two things shocked me – the flash of the lights felt like someone blowing a puff of air on my skin and the smell of burning hair (mine). So maybe a few pre cancerous cells accrued, it was all for a good cause though – Art and making the cover of Jerry’s Steidl book!

www.CasedImage.com

[jdanforth]

I’ve read somewhere that some Daguerreian rooms featured blue-glass skylights.

I read a great book about early Hollywood portrait photography and they showed some of the lighting setups. Often they would use the giant spotlights made by the Klieg company. The effect on the subjects was so pronounced and detrimental that the term “Klieg Eye” evolved to describe “conjunctivitis, edema of the eyelids, lacrimation, and photophobia due to exposure to intense lights”!

[corey r]

Its awesome to log on in order to pose a question and find that someone else is has already posted it. I’m also wondering what is too much light? Beyond Klieg eye, what are the other risks of exposure to intense light (beyond getting a tan)?

[drdag]

Klieg eye is probably the same as ‘arc eye’ a very painful affliction received after being exxposed to an unprotected view of mig, tig or arc welding for a short period. I have had it and it is in the top ten of nasty things I have had/done to myself.

[jgmotamedi]

I have read also that the 19th century Daguerreian studios had blue tinted windows, but it seems sort of asinine to me. After all, blue glass would just filter out some of the non-blue light, it wouldn’t increase the blue or UV light and certainly wouldn’t decrease exposure time. Bad 19th century science? Or perhaps it aided the operators judging exposure since the irrelevant light was partially reduced?

Anyhow, Klieg eye is the same thing as snow blindness and was caused by carbon arc lights, which are not available any longer. However, a number of light sources, notably high wattage mercury or metal halide, and pulsed xenon do produce enough UV to cause eye or skin damage so one should be cautious in selecting and using light sources.

[Jon Lewis]

From what I’ve read, the blue glass (or bottles filled with blue vitriol) were used to decrease the brightness of the light coming in without reducing the exposure time in order to alleviate the pesky Kliegarcsnowdag eye.

[jgmotamedi]

Ah, I that makes sense. The blue light would certainly decrease squinting, but I wonder if the blue glass could increase the likelihood of Kliegarcsnowdag eye, as it might fool the brain into thinking there was less light than there actually was, and open up the eye’s iris–much like during a solar eclipse.

Or am I being silly?

[jgmotamedi]

Oh, never mind, I was just being foolish. Windowpane glass will filter out enough of the UV light so as not to cause any damage. After all, you can’t really get a sunburn through a window can you?

[drdag]

Lens is made of glass though??

[Jon Lewis]

It’s my understanding that modern windows are coated to filter out some UV but mostly UVA (320-400nm) and not so much UVB (290-320nm). UVA is the nasty stuff that can cause cancer and turns your dna into swiss cheese. UVB is responsible for sun burns and isn’t as bad as UVA but isn’t that great either. UVB does catalyze vitamin D production in the skin so its necessary in doses (or one can take a supplement). I suppose if you use UVB to expose your dags you could advertise a portrait sitting as a natural way to prevent rickets…

I’ve asked this before but I’ll try it again: has anyone ever seen a sensitivity curve for a daguerreotype plate of any variety? Might be useful in finding good indoor lights to use without maiming the model.

[jgmotamedi]

Indeed, lenses are made of glass and filter out significant portions of UV light. It should be a problem, yet there was an article somewhere (?) about the use of a special Zeiss UV-passing lens with Daguerreotypes. The upshot was, oddly, that this special quartz crystal lens didn’t significantly decrease exposures with Daguerreotypes.

[Jon Lewis]

Here’s something interesting about lenses from the Wikipedia article on UV photography:

Quote:

Only special developed lenses made of quartz (fused silica) or quartz and fluoride can be used. Using these lenses allow the camera to reach the range 180..200 nm. Lenses based purely on quartz show a distinct focus shift between visible and UV light, whereas the later developed fluoride/quartz lenses are fully color corrected without focus shift. Examples of the latter type are the Nikon UV Nikkor 105 mm, the Hasselblad (Zeiss) UV Sonnar 105 mm and the Asahi Pentax Ultra Achromatic Takumar 85 mm.

[jdanforth]

In addition to the debatable usefulness of blue glass for daguerreian studios on the exposure, they must have curtailed a great deal of heat in the for of IR absorption. That must surely have been a benefit in those days!

[CasedImage]

That’s an interesting definition of lens glass. Kingslake mentions that the early lens were not achromatic and had that disparity between visual and chemical focus. Claudet solved it by using a stepped wheel (focimeter) in the scene of test plates that when processed showed the adjustment needed. As Kingslake mentions, the advent of achromatic lens that used both crown and flint glass corrected the problem and apparently these early lenses were well suited to orthochromatic photo processes like the Daguerreotype.

www.CasedImage.com

[RonF]

RE: Sensitivity Curve (~340-400 nm; UVA and perhaps some violet)

When I was looking into this a while back, I found one reference to this. It’s not a curve per se but it may help answer Jon L’s question and with the topic of lighting etc.

http://www.photobiology.info/Hockberger.html

“In 1842, Becquerel and Draper independently showed that when sunlight was passed through a prism onto a daguerreotype plate (a gelatin emulsion containing silver iodide), wavelengths between 340-400 nm induced a photochemical reaction.”

(I am thinking that the “gelatin emulsion” is an error in this modern interpretation of the old documents, but I assume that they transcribed the numbers right.)

Depending which source I believe, 340-400 nm is either mostly in the UVA with a little violet, or it is all in the UVA.

[botticelli1972]

Just a side note: the other day I was bored and read the warning label on a replacement halogen 500watt bulb and it was a UVA exposure warning that stated that exposures greater than 6 hours could cause redness (sunburn?) and skin irritation. Not that we would sit for a 6 hour shot but they do contain the UVA-Larry

[Andy Stockton]

From medical sources 340-400 nm is a portion of the UVA spectrum now known as UVA-1 which is used in a variety of phototherapy lamps. It is a less damaging portion of the spectrum for skin, but it can still cause sunburn. Phototherapy lamps are available in a wide variety of configurations and power levels, but unfortunately like all medical rated equipment they are quite expensive.

[Jon Lewis]

Ron- Thanks for that info, 340-400nm is more or less UVA. I remember reading somewhere that a daguerreotypist (Shlaer?) had used UV haze filters to help improve contrast on his plates and from what I’ve found they cut off anything shorter than 400nm. If that’s so, there must be at least some sensitivity longer than 400nm. Though by cutting out the most sensitive bits of the spectrum one is likely to increase their exposure quite a bit…

[Mike Robinson]

I once did a workshop at the Amon Carter Museum in Texas and the only lighting we had available were UV bulbs (those horrible blacklight bulbs that were used for POP printing and the like). The exposures were comparable to my north light daylight, BUT the skin tones were very unflattering.

Skylight daylight (7000 – 9000 K) is a much better light to work in than UV light tubes. My fastest exposures with indoors (3 seconds with a Petzval) occur in May-June with slightly overcast conditions . My average exposures are 13 seconds with a Voigtlander f/3.3 .

For iodine only daguerreians using mercury the exposures would increase from seconds to minutes. ie 3 seconds for I/Br plate would become 3 minutes for Iodine only plate.

Can anyone offer an opinion on the relatives speeds of Iodine/Mercury vs Becquerel?

Mike

[jgmotamedi]

I have found the difference between Becquerel developed plates and traditional I/Br/Hg plates to be pretty close to a 2.5 stops (10x). So, to follow Mike’s example, a 3 second I/Br/Hg plate becomes a 30 second Becquerel plate. This basically matches with my very limited use of I/Hg plates, which I have found to be about 5x slower (<2 stops) than Becquerel.

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