Re: Durst 138S Replacement Bubs
Quote:
Originally Posted by
Graybeard
I would expect quite a bit of light loss to have occured with the diffusion plate in the Elwood. The condensor system of the Durst should be more efficient and have less transmission light loss. The 150W G40 bulb may prove just adequate; given the low cost of this bulb, it won't be an expensive experiment.
Graybeard,
Indeed it should be more efficient as the condensers focus the light onto the negative.
Also ensure you align / focus the bulb. The Durst has an elegant system to correctly position the bulb for ultimate focus based upon the condensers used and lens focal length.
There is a good article on the Durst USA site (Jensen Optical) on design and use of condenser systems: http://www.durst-pro-usa.com/world_images/artcon.htm
Hope that helps,
Len
Re: Durst 138S Replacement Bubs
Quote:
Originally Posted by
Graybeard
f8
Yes, if you can use f8 that will really help.
Re: Durst 138S Replacement Bubs
Quote:
Originally Posted by
Graybeard
.......
I'll probably begin by trying the 150W Sylvania G40 bulb and see if the source intensity is adequate for me.
Someone else had suggested this bulb a while back, I was leery because it is designated a "decorative" bulb and worried about flicker etc.
How did you find the 100w version in the Elwood?
I have found 150 watts to be good for most of my printing needs, I keep a 250 watt close by for some prints that may need the extra.
Re: Durst 138S Replacement Bubs
Quote:
Originally Posted by
Allen in Montreal
Someone else had suggested this bulb a while back, I was leery because it is designated a "decorative" bulb and worried about flicker etc.
How did you find the 100w version in the Elwood?
I have found 150 watts to be good for most of my printing needs, I keep a 250 watt close by for some prints that may need the extra.
The G40 that I used provided steady light without flicker. The "decorative" designation probably refers to the shperical shape, large size, and opal coating.
I substituted the G40 bulb for the huge PH302 that was in the Elwood when it arrived here. It was necessary to use two hardware store socket extenders to locate the G40 bulb center at the same position as had been the case with the PH 302.
As I mentioned in my earlier posting, the light intensity provides useable exposure times for me. The brighter 150W Sylvania G40 bulb should be even better.
Re: Durst 138S Replacement Bubs
I use the PH211, PH212, and PH213 bulbs on my 138. These produce somewhat higher contrast than the thorn bulbs, but the coverage is fine, at least up to 4x5 negatives.
Cheers,
-andrew
Re: Durst 138S Replacement Bubs
Quote:
Originally Posted by
quine
I use the PH211, PH212, and PH213 bulbs on my 138. These produce somewhat higher contrast than the thorn bulbs, but the coverage is fine, at least up to 4x5 negatives.
Cheers,
-andrew
Ditto on the PH213.
I've been using one in the Durst 138S with completely acceptable results. A typical exposure lately is 30 seconds at f22 for a cropped 11x14 from a 5x7 negative.
Re: Durst 138S Replacement Bubs
Damn,
I forgot to get back to this thread, I did a entire series of tests with a few potential replacements, and then proceeded to sell off my last original Durst bulbs.
An electrical engineer friend ran the test with me.
i will post some pictures and the result this week.
Re: Durst 138S Replacement Bubs
Allen I would be very interested in your results,as I have a 138 allso and one of the thron blubs, think it is 200 watt though.I use 5x7 film.
Mike
Re: Durst 138S Replacement Bubs
Quote:
Originally Posted by
Allen in Montreal
Damn,
I forgot to get back to this thread, I did a entire series of tests with a few potential replacements, and then proceeded to sell off my last original Durst bulbs.
An electrical engineer friend ran the test with me.
i will post some pictures and the result this week.
We're holding our breath Allen.
Very interested in the results of your study.
Re: Durst 138S Replacement Bubs
I am sorry for the delay guys, I am over whelmed with work these days and I just can't keep up.
And now I can't find the notes I made while Marie was doing the math and results for me.
So unfortunately, I have rely on memory for a summery.
Marie is an electrical engineer in a large R+D lab, a complete MENSA type and a perfectionist.
I completely trust her word 100 %.
The search for new bulbs (she came to the lighting suppliers to look at the bulbs with me) started with IC Racer and Graybeard. I took this chance to decide what I needed and bought a box of replacement bulbs now, to ensure future supply, for my Leica V35, the Durst 1200 and the Durst 138. I should be set for life on all fronts.
I wanted a bulb to replace the Durst 200 watt units I have, I find the 300 too bright, even the PH213 at 250 is too bright.
When I picked up a load of Durst gear, there were some bulbs for the Durst I could not identify. IC helped there and shortly after Graybeard posted he was using a G40 bulb which I never considered because it is sold in the "ornamental" bulb section.
So I went in the darkroom and printed with the following bulbs.
PH212 (150 watt)
PH213 (250 watt)
PH302 (500 watt)
Original Durst 200 Watt
Original Durst 300 Watt
150 watt G40 with E26 base.
300 watt 120 volt 3 way with Mogel E 39 base
300 watt 130 volt 3 way with Mogel E 39 base
After many prints, and measuring light fall off etc.
The original bulb was, as most things Durst, perfect!
But at over $100.00 a bulb, I was not looking to buy a bunch of these as backup and sold my last bulbs off.
The PH302 covers perfectly, runs at the right color temp, but is just too bright for my needs but it would be a very suitable replacement for those who can run 500 watts.
The PH300 (150 watts and $200 each at Don's bulbs) would be a great bulb for me, but they are brutally hard to find at reasonable $$.
The PH300 series are rated for a 100 hour life cycle.
I have found the PH212, which is my preferred wattage, will sometimes have light fall off in the corners with a 5x7 negative. So this was an OK substitute, but not ideal.
Both the E39 based lamps covered the 5x7 negative area well. The globe is a little smaller than the original, but we could not see an issue with lack of coverage in the corners and she could not measure any fall off worth noting in the application at hand (scientists can always find some measurable amount of something or other, but she concluded for the application, it was not worth noting).
The idea of the 300 watt 130 volt E39 base was scrapped quickly even while I liked the idea of the larger globe (these bulbs came to me in a Durst haul and were being used in a Durst 184).
I wanted less wattage and running the 130 volt gave me about a 1/2 stop less. Marie showed me the math to illustrate what the lamp should give off, just below (as I recall??) 250 watts not running at the correct voltage. The color shift from not running at full voltage and how that might affect MG filters etc was a concern for me, but we did not bother to pursue this because we had determined we had a suitable replacement and it was not worth the effort to see if my concerns were well founded or not.
The G40 150 watt bulb worked on every level, wattage and size to cover the corners with a 5x7 negative.
The 3 way 300 watt E39 base worked also. The slightly smaller globe showed no corner fall off worth noting. Again, maybe a scientist could measure some and argue the point, but Marie concluded for the application, it was not worth noting.
At the end of session we determined that the G40 lamp with the E26 base was a suitable replacement in the 150 watt level. The G40 has a life expectancy rated at 1000 plus hours.
The 3 way 300 watt E39 base (rated 1000 hours) was very suitable replacement in the 250/300 watt level.
At 7 dollars a bulb for the 3 way 300 watt and 6 dollars for the G40 , I bought a case of each and stashed them under the stairs for future use.
In the mix, I tried some old Sylvania long neck PH301 copies I have.
They seemed to work ok, the globe is slightly smaller than the real PH302 but the coverage was acceptable so I stashed this as backup too.
The G40 wins for daily use, I keep one 3 way 300 watt under the enlarger for special needs.