Practicalities: timing

[csant]

Hi,

I am gathering all required chemicals to start Bequerel, and in the meantime I am wondering about a few things, related to timing.

1) How long does a sensitized plate “last”? i.e. how long after sensitizing it can I take images? (beyond the “take it as soon as possible)

2) How quick after exposing a plate should I develop it? Do I have some time to spare with? (Given my current work habits, and given that I need sun to develop, I am wondering whether I need to plan the development sun hours into the same day I expose the plate…)

Thanks in advance,

c

[Bakody]

Hi,

1: As soon as you can. As I remember maximum 30min and after that you will loose from the image quality. I think I have never wait longer then 15min.

2: I think it’s the same 30min and then you will loose from the quality. I’m not sure about this. I have never wait more then 5min to start to develop it under red light.

For me, under red film the development time takes about 2 and a half hours and I can get black and white images.

Good luck!

http://daginhun.blogspot.com/
 http://www.facebook.com/DagerrotipiaDaguerreotype

[csant]

Thank you, that was quick! One additional question (or rather, curiosity): since I am new to daguerreotypy, I am not familiar with the “slang”… What do you mean by “I can get black and white images”? As opposed to blue (which, as far as I have been reading up, would mean overexposure?)?

c (eager to learn and start…)

[Bakody]

Blue image means underdevelopment (not overexposed), you need more time. Overexposed parts are blue in the mercury development.

Or you can get blue image as well if your red films are not red enough, so need to use more layers from it to able to get real red and able to filter out all the others.

I hope its helps.

http://daginhun.blogspot.com/
 http://www.facebook.com/DagerrotipiaDaguerreotype

[csant]

Thank you very much, it does indeed help to start understanding…

[photolytic]

Perhaps you have read my article on preserving the latent image in Dags. While the article deals with mercury Dags, certain similarities exist. Like film you should not store Dag plates either before or especially after exposure at high temperature (like your car). A quote from the artivle below:

 

If the daguerreian practices under hot and/or humid conditions, the latent image may not

last more than an hour unless more extensive preservation conditions are employed.

Rapid cooling or freezing of the exposed plate, even in a recloseable plastic bag, before

the desiccant has absorbed the moisture therein will frequently cause moisture damage to

the image. Under these conditions, quickly removing the moisture-laden air from the bag

containing the plate has been shown to reduce damage and improve image quality.

 

IMAGE LIFE TEMPERATURE HUMIDITY CONTAINER

15 MINUTES 86F 30C 50% PLATE HOLDER

1 HOUR 68F 20C 30 TO 90% RESEALABLE BAG

24 HOUR 68F 20C 20 TO 30 % RESEALABLE BAG

5 TO 10DAYS 32F 0C 20 TO 30% RESEALABLE BAG

5 TO 10DAYS 32F 0C 20 TO 50% EVACUATED BAG

1-3 WEEKS 0F -18C 20 TO 50% EVACUATED BAG

 

EQUIPMENT FOR PRESERVING THE DAGUERREOTYPE LATENT IMAGE

The easiest method appears to be to seal the plates in their holder in a recloseable plastic

bag, together with a small amount of silica gel or calcium sulfate (DRIERITE®) desiccant, and

store the bag in a bucket of ice water.

One disadvantage of this method is that sufficient time must be allowed for the moisture

trapped in the bag to be absorbed by the desiccant before the plate is cooled to avoid

condensation within the bag.

More rapid removal of moisture and shorter plate thawing times can be achieved by using

a commercially available vacuum-sealing device such as the Tilia Inc. Foodsaver®

system. The disadvantages of this technique are the added equipment required and the

reliance on an electrical power source.

Tilia’s Foodsaver BagVac® appliance is available from Wal-Mart for less than $100

The BagVac® is capable of evacuating approximately 2/3rds of the air (i.e., 250 torr) and

then heat–sealing a plate holder containing a Daguerreotype plate in a heavy walled

plastic bag in less than a minute.

 

Unexposed Dag plates will keep for a day or 2 in the refrigerator if you seal them in a plastic bag with dessicant In a vaccum sealed bag plates will keep for several days in a small cooler with frozen gel packs.

 

Attachments:

You must be logged in to view attached files.

[csant]

Thank you John for your exhaustive reply! I have not read your article yet – I am just slowly finding my way into the daguerroworld…

[csant]

Sorry to revive an old thread… Just came across a small guide to Becquerel dags where it mentions “Store the sensitive plates in a cool place and they will be good for weeks.” ( http://www.newdags.com/becquerel.html )

Is this misleading information, or am I missing something?

[photolytic]

Charlie’s advice on newdags.com is good. Treat the plates like food.

The sensitivity of coated plates will last longer if they are kept cool, but spots may develop if they are not kept dry too. Use silica gel!

After the exposure Bakody’s advice to develop soon is also good.

If lasting, strong, sunlight is not available soon after exposure, get a 500w halogen work light.

Place the light about 30 to 40 cm from the plate which is covered with rubylith and start developing within an hour after exposure.

You can not substitute CFL light bulbs as the color they emit does not contain the same frequencies as incandesent bulbs and will fog the plates. Developing BDags requires both red and infrared light for the best tones without fog.

Rubylith can not create red light. It can only filter out the non-red part of the spectrum from the source of the light.

Development should be complete in about 2-3 hours giving you neutral (not blue) tones.

If more time between exposure and development is allowed the image may appear underexposed (bluish) unless you increase the developing time.  Longer camera exposures may also be required to compensate for latent image fading.

 

[Author]

Posts