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 > Monochrome Work > Monochrome printing techniques

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

Reply
 
Thread Tools Search this Thread Display Modes
  #11  
Old 29th November 2010, 02:19 PM
MarkWalker MarkWalker is offline
Friend
 
Join Date: Oct 2010
Location: Cardigan
Posts: 85
Default

I'm happy to report that the dimness has been solved. I've never come across this before: the lamp failed and I had a spare included with the enlarger, so I fitted it and hey presto, illumination back to what I thought should have been normal (around 25-30 seconds for 12" enlargement). It appears that before it failed the lamp (250 watt) must have dimmed considerably and for a few weeks: I'm not aware of this as a characteristic of halogen lamps. But, problem solved and thanks again for the great responses.

P.S. to Bill, you might also come across some polystyrene sheet used for packing allsorts of stuff that, say, your local computer/electrical shop might have in a bundle to throw out. The advantage of this is that with equal thickness inside the box you won't have to do any centreing of a 'free standing' insert - watch out for static balls (!) of it on the diffuser.
Regards.
Reply With Quote
  #12  
Old 29th November 2010, 02:37 PM
MarkWalker MarkWalker is offline
Friend
 
Join Date: Oct 2010
Location: Cardigan
Posts: 85
Default

Bill, I am sorry for telling you something you have already tried, I have just tracked back.
I think the solution is probably as good as you might get though, because you are still concentrating the light in a similar manner even with a dedicated chamber. I also made a quick attempt with foil and thought there was a hot spot in the illumination and no discernable increase overall. Also, using a piece of thinner perspex (off a light box) didn't help and illumination was uneven - the Devere diffuser is cleverly domed to compensate for fall off.
Please show us what you come up with, anyway, I think it is a helpful subject for anyone struggling with illumination who can't necessarily get or afford manufacturers spares - have you seen the price of a 6x6 mixing chamber from Odyssey ?

Mark.
Reply With Quote
  #13  
Old 29th November 2010, 03:32 PM
Dave miller Dave miller is offline
Friend
 
Join Date: Aug 2008
Posts: 6,322
Default

Quote:
Originally Posted by MarkWalker View Post
I'm happy to report that the dimness has been solved. I've never come across this before: the lamp failed and I had a spare included with the enlarger, so I fitted it and hey presto, illumination back to what I thought should have been normal (around 25-30 seconds for 12" enlargement). It appears that before it failed the lamp (250 watt) must have dimmed considerably and for a few weeks: I'm not aware of this as a characteristic of halogen lamps. But, problem solved and thanks again for the great responses.

P.S. to Bill, you might also come across some polystyrene sheet used for packing allsorts of stuff that, say, your local computer/electrical shop might have in a bundle to throw out. The advantage of this is that with equal thickness inside the box you won't have to do any centreing of a 'free standing' insert - watch out for static balls (!) of it on the diffuser.
Regards.
All lamps dim with age, but some types more than others; although yours seems to have set a record. It's one reason I no longer keep printing exposure time records. The other thing to watch for is corrosion of the lampholder, it's a component that is subject to a great deal of heat, which in itself adds to the corrosion problem. Ideally this should be replaced with the lamp to maintain a low resistance path.
__________________
Regards
Dave
www.davids.org.uk
Reply With Quote
  #14  
Old 29th November 2010, 04:26 PM
MarkWalker MarkWalker is offline
Friend
 
Join Date: Oct 2010
Location: Cardigan
Posts: 85
Default

Thanks, Dave, when I changed the lamp I noticed the holder and leads looked quite recent, the contacts were clean and the porcelain holder quite white. I shall investigate further if there is a lamp burn out problem.
Regards.
Reply With Quote
  #15  
Old 1st December 2010, 02:39 PM
Bill's Avatar
Bill Bill is offline
Moderator & Keeper of the Calendar
 
Join Date: Sep 2008
Location: Barrow - in - Furness
Posts: 1,803
Default

Quote:
Originally Posted by MarkWalker View Post
Bill, I am sorry for telling you something you have already tried, I have just tracked back.
I think the solution is probably as good as you might get though, because you are still concentrating the light in a similar manner even with a dedicated chamber. I also made a quick attempt with foil and thought there was a hot spot in the illumination and no discernable increase overall. Also, using a piece of thinner perspex (off a light box) didn't help and illumination was uneven - the Devere diffuser is cleverly domed to compensate for fall off.
Please show us what you come up with, anyway, I think it is a helpful subject for anyone struggling with illumination who can't necessarily get or afford manufacturers spares - have you seen the price of a 6x6 mixing chamber from Odyssey ?

Mark.
OK Mark will let you know how I get on. I have been looking for either a De VEre light box or failing that a Durst one I could cannibalise similar to Tony.

I dare not think what Odessey would want for one, probably more than I paid for the enlarger.

Bill
Reply With Quote
  #16  
Old 1st December 2010, 04:47 PM
RH Designs's Avatar
RH Designs RH Designs is offline
Friend
 
Join Date: Sep 2008
Location: Yorkshire Dales
Posts: 1,088
Default

Halogen lamps do indeed dim with age. I replaced the one in my LPL once and got a whole stop more light!
__________________
Regards,
Richard

RH Designs darkroom equipment : dalesphoto.co.uk
Reply With Quote
  #17  
Old 4th December 2010, 06:41 PM
vanannan's Avatar
vanannan vanannan is offline
Friend
 
Join Date: Aug 2009
Location: I live in Port Erin on the Isle Of Man
Posts: 740
Default

Sesibox 6x6 and 6x9 on Ebay starting this evening start price £20 each, maybe an opportunity for someone to adapt as I did.
Reply With Quote
  #18  
Old 4th December 2010, 07:08 PM
Bill's Avatar
Bill Bill is offline
Moderator & Keeper of the Calendar
 
Join Date: Sep 2008
Location: Barrow - in - Furness
Posts: 1,803
Default

Quote:
Originally Posted by vanannan View Post
Sesibox 6x6 and 6x9 on Ebay starting this evening start price £20 each, maybe an opportunity for someone to adapt as I did.
Bought a Sivobox 35 this afternoon as the first step to improving my light output.

Will need to work out how to channel the light once it arrives.

Bill
Reply With Quote
  #19  
Old 24th December 2010, 06:30 PM
Bill's Avatar
Bill Bill is offline
Moderator & Keeper of the Calendar
 
Join Date: Sep 2008
Location: Barrow - in - Furness
Posts: 1,803
Default

Quote:
Originally Posted by MarkWalker View Post
Bill,
Please show us what you come up with, anyway, I think it is a helpful subject for anyone struggling with illumination who can't necessarily get or afford manufacturers spares - have you seen the price of a 6x6 mixing chamber from Odyssey ?

Mark.
It's taken some time but I finished my modified piece this afternoon.

I started by buying a Durst Sivobox 35 off the auction site to give me a small shaped diffuser.

It is a bit Heath Robinson but I sort of added bits on as I went. I made a bottom flange by drawing round the existing light box. To this I mounted the Sivobox using the existing tapped holes and screws that came with the box. I discarded the original bottom plastic piece. I then made a 'chimney' out of ply with a bend to change the direction of the light. The whole was lined with metallised Mylar courtesy of BobRob. This was fixed to the Sivobox by a top flange and drilling 4 holes in the Sivobox flange. I have added some images which I hope will show it better. Perhaps if I did it again I would make the side cheek pieces in one.

Just taken some readings with my Analyser Pro. The negative was enlarged to 91/2 x 12 and was measured using the original 4x5 light box and that came in at 57.4 seconds exposure. That was with the enlarger lens 2 stops down. Without changing anything else but the light box I measured again and got 11 seconds exposure. So well worth doing.

Bill
Attached Thumbnails
Click image for larger version

Name:	Durst.jpg
Views:	283
Size:	9.5 KB
ID:	892   Click image for larger version

Name:	Flange.jpg
Views:	282
Size:	12.5 KB
ID:	893   Click image for larger version

Name:	Finished2.jpg
Views:	283
Size:	10.6 KB
ID:	894   Click image for larger version

Name:	Finished.jpg
Views:	302
Size:	11.5 KB
ID:	895   Click image for larger version

Name:	In-Situ.jpg
Views:	287
Size:	22.0 KB
ID:	896  

Reply With Quote
  #20  
Old 24th December 2010, 11:10 PM
vanannan's Avatar
vanannan vanannan is offline
Friend
 
Join Date: Aug 2009
Location: I live in Port Erin on the Isle Of Man
Posts: 740
Default

Quote:
Originally Posted by Bill View Post
It's taken some time but I finished my modified piece this afternoon.

I started by buying a Durst Sivobox 35 off the auction site to give me a small shaped diffuser.

It is a bit Heath Robinson but I sort of added bits on as I went. I made a bottom flange by drawing round the existing light box. To this I mounted the Sivobox using the existing tapped holes and screws that came with the box. I discarded the original bottom plastic piece. I then made a 'chimney' out of ply with a bend to change the direction of the light. The whole was lined with metallised Mylar courtesy of BobRob. This was fixed to the Sivobox by a top flange and drilling 4 holes in the Sivobox flange. I have added some images which I hope will show it better. Perhaps if I did it again I would make the side cheek pieces in one.

Just taken some readings with my Analyser Pro. The negative was enlarged to 91/2 x 12 and was measured using the original 4x5 light box and that came in at 57.4 seconds exposure. That was with the enlarger lens 2 stops down. Without changing anything else but the light box I measured again and got 11 seconds exposure. So well worth doing.

Bill
Well done, merry xmas
Reply With Quote
Reply

Tags
bulb, devere, dim, illumination
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

Similar Threads
Thread Thread Starter Forum Replies Last Post
Wanted: DeVere Dichromat Head Richard S Sale or Wanted 0 17th November 2010 08:58 AM
DeVere Enlarger Neil Smith Auctions of Interest 6 14th September 2010 11:21 AM
Devere Dichroic Filters vanannan Darkroom 7 16th January 2010 10:43 AM
DeVere Monorails Andy Cameras - Large Format 2 14th January 2010 03:33 PM
Devere Dichromat 108 vanannan Sale or Wanted 0 7th October 2009 07:33 PM


All times are GMT. The time now is 05:51 PM.


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