Flashing time units

rogueish · Feb 17, 2005

I'm going to be doing my first "flash" (no jokes please, this is a family site) test strip. I'll put the enlarger to max height, and the lens to min. aperture.
Just for curiousity, what is the time unit starting point you use?
0.1 secound, 0.5 secouds, 1 secound? Longer, shorter?

geraldatwork · Feb 17, 2005

I tried to test for flash times but my exposures weren't long enough . I set the enlarger up to a height to do 11X14 prints with a 35mm negative and set the lens opening to f 16. I did a series of test strips increasing each one slightly about 5 or 6 in total looking for the first one where I could see a change from the base white. The theory being (I think) using the previous time before you can see a change for the flash. Unfortunately as I mentioned my times were too short. I went from about 1/4 second to about 1 1/2 seconds if I recall. So If I got a chance again I would start at the 1 1/2 sec and work my way from there. Hope this helped. Of course lamp intensity and different lenses and heights would affect your results.

rogueish · Feb 17, 2005

geraldatwork said:
I set the enlarger up to a height to do 11X14 prints with a 35mm negative and set the lens opening to f 16.

I've been reading Tim Rudman's The Photographer's Master Printer Course. He says to do with NO negative in the holder and suggested a time unit of 1/2 secound.

ann · Feb 17, 2005

we use 1 sec. units, enlarger at full height, lens stopped down as far as it will go

Peter Schrager · Feb 17, 2005

Flasher?

I use flashing occasionally but I'm surely no expert. The optimum set up is to have 2 enlargers and use one just for the flashing. I'm lazy so I do it with the negative in place using the same aperture I'm exposing at usually for about .4 seconds. It's worked fine for me. You could also do selective flashing by making up some sort of gizmo for the end of a flashlight. Be sure not to go over the threshold of the paper because then it's a waste of paper and time. there is no set time for flashing and I think Mr. Rudman was overeaching when he states "such and such a time" No 2 papers are alike to begin with and usually no 2 batches of emulsion runs are the same either. You'll have to put the time in to see what works for you.
Regards, Peter

KenS · Feb 17, 2005

Flashing

I'll put the enlarger to max height, and the lens to min. aperture.

There is an alternative method of providing a "flash" exposure that I learned a significant number of years ago and was later to learn it is known (by some), as the post (main) exposure "unsafe safelight exposure"... whereby a small painted red light of low wattage (I got mine from the local hardware store.. I believe it is commonly used as a power-on indicator light) in a light reflector placed about 6 feet from the exposed print now resting on some push pins partially inserted into the wall. Depending on the paper, I will normally (when required) use around a nine to twelve exposure. Using this technique, I do not have to make any adjustments to the enlarger that would require resetting everything.

Ken

Jeremy · Feb 17, 2005

rogueish,
I have your wonderful print at home from the exchange (it's taped on the wall next to a number of others above my palladium tray line for inspiration while working as I don't have mats/frames large enough for 11x14 right now), but can't remember what you [real] name is.

You might want to look into picking up Les McLean's Creative B&W Photography book as he goes into flashing and does a bang-up job of describing it for those new to the technique.

rogueish · Feb 17, 2005

Jeremy Moore said:
rogueish,
I have your wonderful print at home from the exchange (it's taped on the wall next to a number of others above my palladium tray line for inspiration while working as I don't have mats/frames large enough for 11x14 right now), but can't remember what you [real] name is.

You might want to look into picking up Les McLean's Creative B&W Photography book as he goes into flashing and does a bang-up job of describing it for those new to the technique.

Thanks for using "wonderful" and "your print" in the same sentence!
I got Les's book for Christmas and it's great! Right now and at time of original post (I'm at my day job) I have Rudman's book I got from the library.
I was just curious as to what anyone else uses as a starting time.

Oh and the name's Iain but theres already a few of us and I won't want to confuse things, kinda like the JMoore mixups...

JackRosa · Feb 17, 2005

I would suggest 1 second increment as a starting point if you have set the enlarger height at its maximum. Another way to calculate flashing exposure is to print a print and then use 1/32 of the exposure as the flashing exposure, without changing lens aperture or enlarger height. This work as a post-exposure as well.

baronfoxx · Feb 17, 2005

rogueish said:
I'm going to be doing my first "flash" (no jokes please, this is a family site) test strip.

R H Designs (UK) make a paper flashing unit which consists of a small timer unit with a 2" square light head on a flexible lead and it works off a 9v pp9 battery.

I just lay the paper to be flashed on the bench hold the light head 18" above the paper and press the timer, no enlargers or setting up is involved, a great bit of gear

glbeas · Feb 17, 2005

I used a small desk lamp hung on the wall and a Timolite timer. The lamp is on a dimmer and I set it up by turning the lamp down low and doing some test strips. Once the best level and time is found the setting is marked. I also took a reading with my analyser for the precise light level as a reference.

Ronald Moravec · Feb 17, 2005

15 watt bulb in a special use ceiling fixture or a spare enlarger. Time with enlarger timer.

I use spare condenser enlarger with 75 watt bulb stopped to 16 and .4 sec. Magnification is 10x. Any more and the whites start to grey.

Flashing time units

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