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  #11  
Old 8th March 2019, 10:25 PM
John King John King is offline
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Default Electronic enlarger timer

I have an Opemus back up enlarger to which I tried a LED screw fit bulb and connected it to my Baeuerle Electronic timer - it didn't work! Well not in the way you would want it to.

The electronic count down timer pulsed on and off with every 1/10th of a second the timer was set to. If your timer is electronic but does not have the count down figures then it should work because when I was given the enlarger it came with a basic electronic timer but did not have 1/10ths of a second settings, nor the count down clock and on that it worked perfectly (except the timer was a bit slow.)
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  #12  
Old 9th March 2019, 01:09 PM
Terry S Terry S is online now
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Thanks for all the comments peoples!

Well I tried my new LED light from B+Q a few times in the darkroom yesterday and yes, exposures seemed exactly the same with both the old filament bulb and the new LED one.

The only thing was, that the test strip with the new LED bulb seemed to print about a grade lower when using a grade 3 filter under the lens...?

I've checked for the one that you say works for you Barry and it seems that B+Q don't have one with an equivalent 75 wattage, only 'dimmable' ones that go up to 60 watts, but I'll wander over again soon as it's so close to double check. If not I'll probably order from your link, although I don't want to end up with a load of bulbs unsuitable at least for the darkroom enlarger!

But it's interesting that some people find the 'warm' bulbs work fine. Could anyone using the 'warm' bulbs confirm that the under the lens filters work at the appropriate grade when compared to a filament one?

And John King, I used a RH timer that has a countdown timer and at least that part of the equation worked fine for me, so maybe it could just be a problem with your timer itself?

Many thanks in advance once more.

Terry S
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  #13  
Old 9th March 2019, 01:43 PM
Richard Gould Richard Gould is offline
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I use the above the lens filters, and cetainly using the analyser pro the grades are the same with either bulb, photocrensta or led, I ran tests when I stated trying them out, the warmtone LED and the photocresnta bulb were the same grade for grade,l but with the cold tone bulb I could not get to grade 5, and all the grades were a grade out, lower if memories serves me
Richard
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  #14  
Old 11th March 2019, 09:26 PM
jeztastic jeztastic is offline
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I use a warm LED bulb and under lens filters with my Leitz 1C, however I don't own a filament bulb and never have done, the enlarger arrived without a working one.

However, I have noticed that that the LED bulbs are rated cooler than tungsten bulbs in terms of Kelvin. I'll have to look it up.

Edit: LED warm bulb is 2700 kelvin, Tungsten is 3200. That's quite a big difference.

Last edited by jeztastic; 11th March 2019 at 09:31 PM.
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  #15  
Old 12th March 2019, 09:20 AM
Alan Clark Alan Clark is offline
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Quote:
Originally Posted by jeztastic View Post
I use a warm LED bulb and under lens filters with my Leitz 1C, however I don't own a filament bulb and never have done, the enlarger arrived without a working one.

However, I have noticed that that the LED bulbs are rated cooler than tungsten bulbs in terms of Kelvin. I'll have to look it up.

Edit: LED warm bulb is 2700 kelvin, Tungsten is 3200. That's quite a big difference.

Jez, you have got this the wrong way round. 2700K isn't cooler than 3200K. It is warmer.
And the difference of 500 isn't big, as you say. 2700K is designated "warm". You have to go all the way to 6000K to reach "cool"

Alan
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  #16  
Old 12th March 2019, 09:51 AM
Richard Gould Richard Gould is offline
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Agree with Alan, 500 isn't big, the slight difference won't make that much difference, I have found by testing with my analyser pro and prints that the cool LED is not as good as the warm 2700 bulb, I would not go back to a filiment bulb,My prints on MG pape are just as good, with no heat, no popping negative, no isk of burning yourself on the enlarger head, Ect
Richard
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  #17  
Old 12th March 2019, 10:09 AM
jeztastic jeztastic is offline
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:
Quote:
Originally Posted by Alan Clark View Post
Jez, you have got this the wrong way round. 2700K isn't cooler than 3200K. It is warmer.
And the difference of 500 isn't big, as you say. 2700K is designated "warm". You have to go all the way to 6000K to reach "cool"

Alan
Thanks for the correction!
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  #18  
Old 12th March 2019, 10:23 AM
Alan Clark Alan Clark is offline
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Hi Jez, you say you use a Leitz 1C. Is that a Focomat? They have a great reputation. I wonder how you find yours. I only have its poor relative - a Leitz Valoy 11 ……!

Alan
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  #19  
Old 12th March 2019, 08:10 PM
jeztastic jeztastic is offline
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Quote:
Originally Posted by Alan Clark View Post
Hi Jez, you say you use a Leitz 1C. Is that a Focomat? They have a great reputation. I wonder how you find yours. I only have its poor relative - a Leitz Valoy 11 ……!

Alan
Yes a focomat. It was given to my father in law by his friend who then passed it on to me. I consider myself very lucky to have it. It is lovely to use, like so many well designed things the quality of it shows and you don't have to think about it. The auto focus is great.

Down sides - it is missing the clip for the focus ring so it is easy to knock it out of focus when changing aperture.
It doesn't have a filter drawer and I haven't found a way to attach below lens Ilford filters. The lens mount is too recessed. I have been lifting the bulb housing and dropping the filter on top of the condenser (advantage of having a nice cool LED bulb) but this would swiftly become a pain for split grade printing.
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  #20  
Old 13th March 2019, 01:18 AM
John King John King is offline
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Quote:
Originally Posted by Richard Gould View Post
I use the above the lens filters, and cetainly using the analyser pro the grades are the same with either bulb, photocrensta or led, I ran tests when I stated trying them out, the warmtone LED and the photocresnta bulb were the same grade for grade,l but with the cold tone bulb I could not get to grade 5, and all the grades were a grade out, lower if memories serves me
Richard

Have you tried a LED bulb that emits a colder light? The LED I have in the darkroom is 6700 degree Kelvin and use it to assess colour balance when printing RA4 It is shed load better than the blue tinted tungsten bulb I used previously. It is the same bulb that would not work in the Opemus enlarger with the electronic timer. It is rated at 70w equivalent output but uses about 15w of power. When I tried the more basic timer there was no problem in getting grade 5 when using Ilford filters, in fact it seemed to be a littler harder.
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