Duka 10 and Kodak paper

[digiconvert]

I have recently bought a Duka 10 safelight for the darkroom , you can read the paper while doing BW but the colour paper I use (Kodak Endura) seems incredibly sensitive to it. I have th light 2 metres/ 6 feet + away from the enlarger and facing a wall on the lowest setting but still get a faint blue 'tinge' on the borders , any one having a similar problem ?

BTW the distance of lamp to baseboard is about the most I can get and I can JUST see to line up paper in the easel (the reason I bought the lamp) at this brightness.

Cheers CJB

 

[Photo Engineer]

Use a Wratten 13 safelight with about a 10 - 15 watt bulb no closer than 4 feet with indirect illumination for Endura paper.

PE

 

[digiconvert]

Is Endura particularly sensitive to the output of a Duka lamp ?

 

[Photo Engineer]

IDK, never used one. I always used what Kodak recommended.

PE

 

[percepts]

firstly it should have a sodium lamp in it.

secondly my duka 50 came with two covers. A red one for use with b+w papers and a white one for use with colour paper.

I've only used it with b+w papers and I had to adjust brightness and direction of lamp (bounced off white ceiling) to get the safe times I wanted which are in excess of 20 minutes for all papers I have tested.

What colour is the face piece which covers the lamp because if its red you are using the wrong one.

 

[Photo Engineer]

The color filter should be dim amber. You could hardly see your hand in front of your face with it.

PE

 

[percepts]

hmmm,

since a sodium lamp only emits 590nm wavelengths which colour paper is supposed not to be sensitive to, the cover serves the purpose of diffusing the light. It doesn't need to act as a filter by being coloured. Hence The cover is white. The brochure images show it with lamp on which makes it look/emit faint amber.

Of course the duka 10 could be different to my duka 50. And if the Duka 10 doesn't have a sodium lamp in it, then yes the cover should be light amber.

 

[pentaxuser]

Sorry to hear about your problems.I have a DUKA 10 and never experienced problems with Kodak Endura paper. As far as I am aware the Duka will only take a sodium light. I have read somewhere that it can take up to 15 mins for the light to warm up to a safe temperature. I suppose I always left my light on this long before exposing the paper. So it follows from this that you cannot switch it off when using the enlarger. It can of course be switched down to 0( this is simply an internal shade device - the lamp intensity remains the same) or covered by a makeshift cover when analysing and exposing.

I used to use it on the setting of 10( goes from 0 to about 25). Mine points to the ceiling so in effect is about 6-7 feet from the enlarger board.

I previously had a Durst tricolour lamp using a normal 15 watt bulb which gave out the same light intensity that PE mentions but as the sodium light works on a different principle then there is no need to put up with light in which you can hardly see a hand in front of your face.

So to sum up. The DUKA 10 does work with Kodak Endura in my experience and as far as my experience goes I can only suggest that:
1. You allow it 15 mins to warm up
2. Try using it at no more than a setting of 10. The light level is still pretty good
3. Bounce the light off the ceiling if possible to vene out the illumination

It may be possible that if the light is about to fail then the colour transmittance becomes unsafe but I don't know.

Try the spare bulb in it. If you haven't got one then I'd certainly try and get one. Nova and Secondhand Darkroom Supplies sometimes get in DUKAs. Both places are within reasonable travelling distance of your place. Might be worth a phone call to them and a discussion. Stewart Band at Nova(assuming he is still there) is particularly helpful and uses a DUKA himself.

Incidentally the sodium lights are so expensive that I'd be tempted to save the DUKA for colour printing only. I use an Ilford 902 for B&W. If the nromal 15 W bulb goes it's about a £1 max for a replacement and you can switch off and on to your heart's content.

Let us all know how you get on Here's hoping you resolve things I can see of no reason why you won't be able to.

pentaxuser

 

[Photo Engineer]

If you look at the Kodak web site, you can find the spectral sensitivity of Endura paper. From this you can judge what wavelength and how much intensity to use.

PE

 

[digiconvert]

Thanks for your replies - I've been playing with my new Labometer so have not picked them up until today. However I now turn the light on when I know I am going to do some printing later and live the rest of my life for a bit - clean the rabbit out , talk to my long suffering wife (just had a cancer scare 0 thankfully all is well !) and then go to the darkroom. I also have the light above the level of the paper easel AND pointing to the cieling - no problems any more and I actually get the paper aligned in the easel properly now and curse less when I drop something

As for BW , I have tried it with Forte paper at almost full power and there were no problems, I didn't need any additional light at any time in the session.

Cheers CJB

 

[digiconvert]

Sorry meant to say I recommend Second Hand Darkroom to anyone - the service is absaloutely fantastic and the stuff is not as cheap as ebay but it always works and on the one occasion it didnt I got excellent support !

 

[pentaxuser]

Digiconvert. Glad that everything is sorted. The only problem with Secondhand Darkroom I have found is that sometimes it undersells itself. The Christian ethic I suspect tends to get in the way of naked commercialism and long may that continue provided they turn over a resonable profit.

pentaxuser