Results of leaking enlarger tests

greenspun.com : LUSENET : Large format photography : One Thread

As many asked from my last post about my Saunders/LPL 4500 XLG enlarger leaking light(http://hv.greenspun.com/bboard/q-and-a-fetch-msg.tcl?msg_id=005NaN), I am posting my results from tests that I have just run.

My safe light (Patterson orange tabletop dome light 15w) tested safe even at ten minutes at 6 feet away (I process prints in a JOBO so my paper is exposed for only the time of the enlargement exposure; no trays). I was using Polymax Fine Art DW FB glossy paper pre-exposed to a light gray of approx Zone VI-VII.

I then put the lens cap on the enlarger and ran the same ten minute test on a pre-exposed piece of paper with the safe light off but TONS of light spilling out of every conceivable crevice of my enlarger. I have black velvet on the walls in the corner that I use for the enlarger so there is no wall bounce, but after my eyes got used to the dark, I was amazed at how much light was hitting all around my easle. I could easily see my hand with great detail. I could just make out the coins that I placed on the paper for incremental testing on this piece of paper. I also tried to do the worst case scenario by having the enlarger head way down close to the paper. I was sure that my test would be very positive by the looks osf all of this.

To my great surprise, the print showed not a trace of fog from all of this light. My conclusion is that at least in my situation, it looks like I don't have to spend any time making "miniskirts" for my leaky enlarger (actually I'm quite relieved; this seemed like a big pain to me). My thoughts are that enlarging paper is slow enough that this type of light is insignificant. So as many of the people who responded to my previous post hinted at, it may not make any difference with the leaks in this enlarger unless you have a direct bounce off a wall or obvious light hitting the paper. Light falling outside of the paper doesn't seem to have any effect at least in my case.

Any comments are welcome and I posted this in the spirit of feedback to all those who responded with prevoius comments about light leaks in enlargers in general...

Scott

-- Scott Jones (scottsdesk@home.com), June 04, 2001

Answers

Thanks for sharing your results.

I've never detected any problems from light leaks, but that doesn't mean they can't cause problems.

-- Charlie Strack (charlie_strack@sti.com), June 04, 2001.


Scott,

Thanks for the update... This is valuable information. Now we want to see some of your work :) Have fun with that new enlarger!

-- Jim (jimzpace@yahoo.com), June 04, 2001.


Scott,

Did you dry the paper before evaluating the results? Fiber paper usually dries down darker than when it is wet. Thanks for sharing this!

Nick

-- Nicholas Fiduccia (nfiduccia@earthlink.net), June 05, 2001.


Yep! Dried paper still shows no signs of fogging.

-- Scott Jones (scottsdesk@home.com), June 05, 2001.

Scott, If your tests prove ok then I wouldn't worry about the light leaks, BUT, I do second the advice on your previous thread about wearing light coloured clothes when printing. I wear a red t-shirt after realising that the white one I used to wear seemed to "illuminate" the easel.Whether this had anu effect on the paper, I'm not sure, it was just a little disconcerting! Hey, who knows, maybe we could market red darkroom t-shirts!!!! Regards Paul

-- paul owen (paulowen_2000@yahoo.com), June 05, 2001.


Thanks for posting your test results. I use the same enlarger. Do you use the masking attachment that goes under the negative carrier? That thing leaks a lot light. I took mine apart and painted the underside flat black. Seems to help a bit.

-- Chris Ellinger (chris@ellingerphoto.com), June 05, 2001.

Scott, I received the negative masking stage and the glass 5x4 neg carrier that I ordered this afternoon, and have just finished some prints. The glass carrier makes a real difference in keeping the film flat, especially 6x9 negs that for some reason didn't want to lie flat. But the masking stage does leak a hell of a lot of light at its edges. I have had a quick look and I think that I will need to add a few strips of weatherseal type foam strip. The light is escaping through the slit that allows the masking blades to travel and is spilling over the frame. A real pain in the ass!! The stage just cost me 100. Still, a little DIY and it should be right (fingers crossed) I ran a quick test and there doesn't appear to be any fogging, and the prints are great, but its still a bit offputting when these beams of light are illuminating my darkroom!! Regards Paul

-- paul owen (paulowen_2000@yahoo.com), June 05, 2001.

Moderation questions? read the FAQ