"Photo" Lamp for Durst M605 Color Enlarger?

[Obtong]

My Durst M605 Color enlarger has a 12v 100w Tungsten-Halogen bulb, and like others who have used the M605 Color, I too am finding that my exposures times are way too short, even at f/16. (5 seconds for a 5x7 print.) I have tried switching to the 6x6 box and it has helped a little. I have also tried dialing in equal amounts of Y/M/C but find it inconvenient when using the color head to change paper grade filtration. So, the solution I believe, is to get a lower wattage bulb.

Can I use any Tungsten-Halogen bulb like this one for $1.39 or do I need to get a special "photo" lamp? I have checked B&H and they have a "General Brand" 75w lamp for $39.95. The Amazon one is much cheaper...

~Dom

 

[bdial]

The color temperature is probably off on the home center bulbs, which likely will affect your filtration some, but if you're only doing B&W, it shouldn't be a problem, though it may require some testing. Are you using only Y or M, or are you using the combined Y+M filtration?

 

[ic-racer]

Get a Rosco neutral density gel for less than $10 and put it on top of the mixing box.
In terms of experimenting with different bulbs, I'm not sure the effect on the regulated power supply. Maybe Nicholas Lindan will chime in here, but it may not be a good idea to run a different wattage bulb from a regulated power supply.

 

[Obtong]

Home Depot has 12v 50w lamps for 69¢. I think I will try one and see how it works on my M605.

 

[MattKing]

Most of the hardware store bulbs I've seen either have different specs, or a different base, or both.

The colour temperature issue is quite important. If it varies from bulb to bulb, it could drive you nuts if you go through a lot of them.

If you use variable contrast materials, and a bulb is deficient in blue, you may not like the results.

 

[Obtong]

The colour temperature issue is quite important.QUOTE]

What should the colour temperature be? Some boxes show the colour temperature. I seem to recall one brand with a colour temperature of 3500K.

~Dom

 

[bdial]

To find the color temperature for the normal bulb, the easiest way is to google the three letter bulb designator, you'll get lots of hits from the various suppliers, and usually they show the full specs.

 

[pentaxuser]

Hi Dom. I hope you got my PM. Certainly compared to home centre bulbs the likes of the Osram XENOPHOT 75W is expensive. Assuming you try a home center one and that you can find a 75W one and another big assumption that such bulbs are the same as in the U.K. let us know how it goes.

I haven't see any 75W bulbs in our U.K. equivalent of home center but plenty of 50W ones. I suspect that if there are no colour neg printing colour balance problems with a 50W, the exposure times should still be fine and with B&W may be OK with an aperture of f5.6 or max f8 but bigger than 8x10 might be rather long exposures with dual fitration especially.


As you will have gathered if the home centre bulbs are OK then I'd give them a go myself.

Thanks

pentaxuser

 

[Bob-D659]

Here's a link to the Ushio bulb catalogs, all you never wanted to know about bulbs.

Dead Link Removed

 

[Nicholas Lindan]

There should be no problem substituting a 50W 12V lamp for a 100W 12V lamp. It will only reduce your illumination by 1 stop/double your print times. If you are using it for B&W printing the color temperature will be largely irrelevant.

The JCR/M lamp on the B&H site is a projector lamp. It has a true parabolic reflector, an aligned filament and a special base - needed when used as part of the condenser optics of a slide projector. It is also the reason the lamp costs about 30x what it should.

I take it your enlarger is a diffusion system with a mixing box. For this you don't care one whit what sort of reflector the lamp has, and the cheap Home Depot lamp should work fine.

There is one caveat - the base of the lamp. General purpose halogen lamps have a base with two pins. Projector lamps have a base with two blades and they have a collar to hold the lamp in alignment. If Durst uses projector style lamps you may find it necessary to replace the lamp holder and socket to enable you to use the cheaper lamps. As the socket for a Halogen lamp is considered a replacement item - they wear out with the heat - this isn't as big a deal as it might seem at first.

 

[Obtong]

Here's a link to the Ushio bulb catalogs, all you never wanted to know about bulbs.

Dead Link Removed

That's a great resource! Thanks!

 

[Obtong]

There should be no problem substituting a 50W 12V lamp for a 100W 12V lamp. It will only reduce your illumination by 1 stop/double your print times. If you are using it for B&W printing the color temperature will be largely irrelevant.

Good to know. Right now I'm getting really short exposure times of about 5 seconds for a 5x7 print which can be a little awkward, particularly if the correct exposure is somewhere between 4 or 5 seconds. If I can increase my standard exposure time, then I will have a larger range of exposure times availble to me in order to get the correct exposure. My timer only has one second intervals.

The JCR/M lamp on the B&H site is a projector lamp. It has a true parabolic reflector, an aligned filament and a special base - needed when used as part of the condenser optics of a slide projector. It is also the reason the lamp costs about 30x what it should.

I never knew bulbs were so different/sophisticated!

I take it your enlarger is a diffusion system with a mixing box. For this you don't care one whit what sort of reflector the lamp has, and the cheap Home Depot lamp should work fine.

I hope so!

There is one caveat - the base of the lamp. General purpose halogen lamps have a base with two pins. Projector lamps have a base with two blades and they have a collar to hold the lamp in alignment. If Durst uses projector style lamps you may find it necessary to replace the lamp holder and socket to enable you to use the cheaper lamps. As the socket for a Halogen lamp is considered a replacement item - they wear out with the heat - this isn't as big a deal as it might seem at first.

Yes, although the pins look the same, the Home Depot lamp ended up being a tight fit. I'm looking at finding a source for replacement holders so I can wire two in parallel. This would give me the option of using either the Durst recommeded lamp or the Home Depot lamp.

As you will have gathered if the home centre bulbs are OK then I'd give them a go myself.

It's going to be a few days before I get to my darkroom again (I'm in the middle of painting my house), but I'll be sure to post my findings.

Thanks!
~Dom