Support our Sponsors, they keep FADU free:   AG Photographic   The Imaging Warehouse   Process Supplies   RH Designs   Second-hand Darkroom Supplies  

Notices

Go Back   Film and Darkroom User > Equipment > Darkroom

  ***   Click here for the FADU 2015/2014 Yearbooks   ***

Reply
 
Thread Tools Search this Thread Display Modes
  #1  
Old 3rd March 2009, 04:13 PM
Martin Aislabie's Avatar
Martin Aislabie Martin Aislabie is online now
Friend
 
Join Date: Nov 2008
Location: Stratford-upon-Avon, England
Posts: 2,080
Question Duka 50 Controls

I have just bought a 2nd hand Kaiser Duka 50 Safelight

The Safelight has 2 controls :-

The front control labelled 1 to 50 (I think) controls the lamp output

What does the rear control do ? (I have tried moving it but can see no effect)


Can anyone enlighten me what the rear of these 2 controls does

Thanks

Martin
Reply With Quote
  #2  
Old 3rd March 2009, 04:43 PM
Argentum's Avatar
Argentum Argentum is offline
Friend
 
Join Date: Sep 2008
Location: Sceptred Isle
Posts: 3,066
Default

I have one these stored away somewhere. You should have two pieces of coloured perspex with it. One a pale straw colour the other one red. For black and white, use the red one. Either way, take which ever one is fitted off and you will see how the sliders work. I never did figure out why you should need two of them. There is little shroud which is rotated to restrict light output. I forget which slider does what.

p.s. the straw coloured perspex will work for B+W but safe times are shorter. Depends how much light you need. With the red one I got in excess of 20 mins safe with forte polywarmtone but it was pretty dark.
__________________
An old dog learning new tricks
Reply With Quote
  #3  
Old 3rd March 2009, 04:45 PM
RH Designs's Avatar
RH Designs RH Designs is offline
Friend
 
Join Date: Sep 2008
Location: Yorkshire Dales
Posts: 1,088
Default

Sorry I can't help you with the controls Martin, but don't connect it to your StopClock because Duka 50s don't like being switched off and then on again. The tube will probably not re-strike properly, and you may shorten its life. You don't want to do the latter believe me, they cost a fortune ...
__________________
Regards,
Richard

RH Designs darkroom equipment : dalesphoto.co.uk
Reply With Quote
  #4  
Old 3rd March 2009, 04:51 PM
Argentum's Avatar
Argentum Argentum is offline
Friend
 
Join Date: Sep 2008
Location: Sceptred Isle
Posts: 3,066
Default

I concur with Richard, but also, there a long warm up time with sodium lamps so even if turning on off diddn't shorten lamp life, they need that warm up time to get to correct output for colour papers.
__________________
An old dog learning new tricks
Reply With Quote
  #5  
Old 3rd March 2009, 05:35 PM
Martin Aislabie's Avatar
Martin Aislabie Martin Aislabie is online now
Friend
 
Join Date: Nov 2008
Location: Stratford-upon-Avon, England
Posts: 2,080
Default

It came with the dark red coloured front cover & that was it.

I knew about not switching sodium lights off and on again, your right - they really don't like it.

We have the same problem in the lighting in the workshops at work but there they have some fancy mechanism for a minimum time between being switched off and on again.

I intend to mount it at the other end of my darkroom to the Enlarger and then just leave it for the whole duration of the Darkroom.

The main Darkroom at University had a Sodium Safelight and it look the best part of an hour to warm up but once it was warm it was so bright I could read a newpaper with it and never had to worry about paper fogging.

Martin
Reply With Quote
  #6  
Old 29th May 2022, 12:51 PM
LordClive LordClive is offline
Friend
 
Join Date: Oct 2021
Location: Farnborough Hants.
Posts: 22
Default

Has anyone got a Red Filter for the Kaiser Duka 50 safelight that they no longer have need of. Please let me know how much you would want for it
Reply With Quote
  #7  
Old 29th May 2022, 02:19 PM
Nat Polton Nat Polton is offline
Friend
 
Join Date: Oct 2019
Posts: 758
Default

I was looking for DUKA 50 Instructions two years ago.
There was a good response here, and alexmuir put up a copy of the original makers instructions.

Have a search here on Fadu for my questions on 30th April 2020

The title was

Wotan duka 50 Colour Safelight.Instructions.

I managed to print off a copy for myself at the time, but have never seen the instructions in print anywhere else.
Thankyou alexmuir

Cheers.
__________________
It will all be over by Christmas.
Reply With Quote
  #8  
Old 29th May 2022, 03:11 PM
Mike O'Pray Mike O'Pray is offline
Friend
 
Join Date: Oct 2008
Location: Daventry, Northants
Posts: 8,968
Default

I has forgotten about your thread Nat but it would seem that the rearmost slider which clicks as you move it, is intended as a stop for the illumination control which is the front slider to prevent inadvertent movement of the front slider beyond the required illumination setting

So that's its purpose and for some of us such as Nat and Alex it works and for others such as John and I it doesn't as the stop's internal mechanism may be broken. I suspect this may be case with a lot of DUKAs now due to use and age but no matter as you'd have to be very unlucky to inadvertently move the front slider. It is just too stiff to be moved by being brushed against and would need a conscious effort to move it. At least that's the case with my DUKA

So no real worries

Mike
Reply With Quote
  #9  
Old 29th May 2022, 05:24 PM
John King John King is offline
Friend
 
Join Date: Nov 2012
Location: County Durham
Posts: 3,318
Default Duka Safelight

There are several versions of the DUKA 50 and mine does not have the 2nd adjustment, I know they made several versions (mine is badged Kaiser) so they may have omitted to fit it. Just use the adjuster on the outer rim of the lamp house. I bought mine new in 1993(ish) and replaced the bulb once after knocking the lamp over when it was switched on. I was able to buy a bulb then - for around £105 and a spare one, some time later for about £90. A new complete safelight when they were available were over £200!

For Lord Clives information. There is no need to use the red filter, that is something else that seems to be superfluous for the lamps use. I do colour and B&W with the white filter only and with B&W there is no fogging what so ever even at full output. If colour paper is 'blind' to the light given out by the sodium bulb, then it stands to reason that B&W will be even more so. Probably the reason it is never mentioned in B&W paper guides may be due to their now uncommon use.

As RH Designs has said, the bulbs can reduce their working life with repeated switching on and off, This was in the original instructions, but they have not been available for several years now. I think I must have the only brand new one in captivity which is the one I bought as a spare and I'm keeping in case this one gives up the ghost on me. After 20+ years this bulb has served me well, but it still soldiers on. I have read somewhere that after long use the emitted spectrum is supposed to change, it must be very long then because min is just as good when it was new except the warm up time is getting longer. Be warned though the wattage used to run the safelight is a lot more than a small tungsten bulb in a conventional safelight and a huge amount more than that if you have converted to using a LED bulb

For B&W you can use it on full power for as long as you like. I have had a long exposure of over 3 mins with the old MG4 and that did not affect the paper what so ever. AS I use MG5 exclusively now it looks as if it is very much the same with the new paper.

For colour I have mine set at 10 on the scale and the lamp house is on a shelf behind me shining up at the ceiling and reflecting back to the wet bench. As it is not in direct line of sight this is probably overkill, but after your eyes get used to the light it is quite workable, and better safe than sorry.

Last edited by John King; 29th May 2022 at 05:30 PM.
Reply With Quote
  #10  
Old 29th May 2022, 09:41 PM
Reginald S's Avatar
Reginald S Reginald S is offline
Friend
 
Join Date: Mar 2022
Location: Germany
Posts: 327
Default

Quote:
Originally Posted by John King View Post
If colour paper is 'blind' to the light given out by the sodium bulb, then it stands to reason that B&W will be even more so..
John, could you please explain the details behind the stand-to-hand principle?
Years ago I bought an Osram Duka 50 without red filter.

Cutting down my paper rolls takes some time, and after cutting to size the normal workflow with dodging, burning and developing for 3 minutes will follow so that my paper sees a lot of light before developing it.

This Osram bulb could be worth to give her a try in my situation.
Reply With Quote
Reply
Support our Sponsors, they keep FADU free:   AG Photographic   The Imaging Warehouse   Process Supplies   RH Designs   Second-hand Darkroom Supplies  

Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT. The time now is 04:48 PM.


Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2024, vBulletin Solutions Inc.