My LPL Enlarger is Getting Dim

[brian steinberger]

I have the LPL VCCE 7700 enlarger and noticed over the last few months my exposure times are getting longer. Today I went in to print and it wanted exposures up to 6 and 7 stops. That's ridiculous. I checked the lamp and it's seated properly. I just got the enlarger new about a year ago. How often do the lamps need changed? Why wouldn't they just burn out like any other bulb?

Also, could it be the power supply going bad? The paper and developer were both fine. I'm hoping changing the lamp will be the quick and cheap fix, but I'm worried it's something more. Advice?

 

[paul_c5x4]

Unlikely the power supply is at fault. Certainly, I would change the lamp as a first step - Even although they keep on shining nice and bright, I have found the colour changes over time and now aim to change mine after about fifty hours (in a Durst L1200). Lamps are cheap, so it is not a major expense and I can still sell the old ones on ebay...

 

[bdial]

When this happened to my 4x5 LPL it was the power supply. I tried a bulb change first, which didn't help.
The sockets can become corroded and cause dimming as well.
First step would be to examine the bulb's condition, and then make sure all the connections between it and the power supply are in good shape.

 

[eclarke]

You need to change bulbs frequently, even when still bright they lose wavelengths and the prints don't sparkle like they should. Go to someplace like ebulbs.com, don't pay LPL prices..Evan Clarke

 

[brian steinberger]

Thanks guys. I did order a new bulb from B&H photo. $12. Should be here early next week. I'm going to go and check the contacts now and make sure they're ok. I'm hoping it just needs a new bulb. How often are you guys changing bulbs? I can't imagine it being the power supply. I just bought the enlarger a year ago!

 

[JSebrof]

Silly question, but you don't have the dimming knob turned? Probably not, I do remember printing once and the bulb died during printing. After replacing it, the same exposure with the new bulb over-exposed the paper 1-2 stops from where it had been right before the previous bulb died.

 

[brian steinberger]

Does the 7700 have a dimmer knob? I've heard the 4x5 version does. Is there something I don't know about?

 

[JSebrof]

My bad, I was referring to the 4x5, I'm not used to the 4 digit numbers for the enlargers. I'm not sure if the med. format enlarger has the dimmer. To be fair, on the 4x5 it isn't really a dimmer so much as it's a metal plate with holes in it that can swing in front of the light to lessen the amount of light output.

 

[eclarke]

The life of your bulb depends on how much you print. I watch my prints and when it seems like they just don't have all the qualities you normally get, ditch the bulb. They are cheap compared to paper!..EC

 

[bwrules]

Does it look like the filtration is getting dim too? I mean the magenta filtration. That's what's happening with my enlarger. I am worried that the head is broken . I hope it's as simple as the bulb going. It doesn't seem dim though.

 

[MattKing]

Are the dichroic filters dirty?

 

[ic-racer]

You got it NEW a year ago? What are these thing going for, $2500? I'd try to get it repaired under warranty (should be 5 years).

 

[bwrules]

Are the dichroic filters dirty?

No, they look clean.

 

[brian steinberger]

You got it NEW a year ago? What are these thing going for, $2500? I'd try to get it repaired under warranty (should be 5 years).

I bought it as new old stock. I got a hell of a deal off of ebay. So there's no warranty. It was brand new out of the box. I'm hoping it's just the bulb. If I have to replace the bulb once a year so be it. I'm extremely happy with the enlarger otherwise.

 

[bwrules]

Is magenta supposed to fade as the bulb is losing spectrum? Thanks.

 

[ic-racer]

I bought it as new old stock. I got a hell of a deal off of ebay. So there's no warranty. It was brand new out of the box. I'm hoping it's just the bulb. If I have to replace the bulb once a year so be it. I'm extremely happy with the enlarger otherwise.

I'm a little worried it is not the bulb, usually those bulbs go suddenly. Nothing wrong with checking with a new bulb, you can alway use a second spare bulb.

If you have a way to measure AC voltage you can check the terminals with a bulb in place and the lamp on and see if you get 82.0 V

If not, then something is amiss. The first place to check would be contacts, like any connectors or the bulb socket itself. Something could easily get corroded during storage, even on new equipment.

 

[brian steinberger]

I did try plugging in and un-plugging the bulb quite a few times to see if I could clean the contacts. When measuring the light intensity before and after this did not do anything. Replacing the bulb will be the first step and if that is not the case then I can go from there. Let's hope it doesn't get to that point.

 

[bwrules]

Fixed my magenta weakening issue. The light bulb was not centered.

 

[brian steinberger]

Just to update everyone, I got the new bulb today and that's what it was. I measured the light wide open at grade 2 with a Darkroom Automation enlarging meter at a certain height with the old bulb and got a measurement of 3.4. As soon as I put the new bulb in and turned it on I could tell a huge difference. The meter now measured 6.8, twice as much light!! I'm happy that this was the problem. Now I need to write that measurement down and remember to check it several months from now.

 

[ic-racer]

Thats good news.

 

[eclarke]

Just to update everyone, I got the new bulb today and that's what it was. I measured the light wide open at grade 2 with a Darkroom Automation enlarging meter at a certain height with the old bulb and got a measurement of 3.4. As soon as I put the new bulb in and turned it on I could tell a huge difference. The meter now measured 6.8, twice as much light!! I'm happy that this was the problem. Now I need to write that measurement down and remember to check it several months from now.

As I said before, the minute your prints lose their sparkle, change the bulb. The lamps will continue to give a lot of light long after they are useful for printing..EC

 

[Kirk Keyes]

As I said before, the minute your prints lose their sparkle, change the bulb. The lamps will continue to give a lot of light long after they are useful for printing..EC

This sounds like voodoo to me.

As long as you can correct for the yellow color shift of an aging bulb with the magenta filtration, you should not have any "loss of sparkle".

 

[brian steinberger]

What or who exactly would use the bulb after it's photo printing life is over?

 

[Nicholas Lindan]

I measured the light ... with a Darkroom Automation enlarging meter ... with the old bulb and got a measurement of 3.4. ... I put the new bulb in and ... now measure 6.8, twice as much light!!

Er. that's in stops. 3.4 -> 6.8 = 3.4 stops increase = 2 ^ 3.4 = 10.6 times more light

Multiplying stops (multiplying logarithms) is the same as raising the underlying linear measurement to a power - it doesn't make much sense to say "the new light is equal to the old light squared".

Keeping track of light intensity is standard practice in graphic arts. It is a good idea in the darkroom too. Note the measurement conditions and meter reading on a 3x5 card. Keep the card with the enlarger and check the light output periodically, comparing it with the new. An enlarging meter (or graphic arts integtrator) will compensate the exposures as the light grows dim and a failing lamp can catch up with you.

An incandescent lamp will lose a lot of intensity at the end of life as the metal from the filament gets deposited on the bulb glass.

 

[brian steinberger]

Thanks for clarifying Nicholas. I was questioning myself when I originally typed that. So a 3.4 stop increase.. WOW!