LED replacement for PH140

[Melvin J Bramley]

I have a LPL C670 that pops negatives to a frustrating degree.
Is there an alternative LED bulb to the standard PH140?

 

[ags2mikon]

I was just up on B&H's website looking at the Nanlite pavobulb 10c for a similar project.

 

[Melvin J Bramley]

If this physically fits it may do the job?

 

[albada]

If you look at the specifications of that bulb here, you'll see that it consumes 10 watts. That's equivalent to a 60-70 watt tungsten bulb, which is not bright compared to most enlargers. But if the PH140 is only 75 watts, which I read in one place, then maybe the Pavobulb will be okay. I suggest checking brightness first.

 

[Melvin J Bramley]

The physical dimensions may be an issue.
Perhaps there is an adaptor to use other bulbs?

 

[MattKing]

Spectrum is also potentially a problem, if you are using multigrade paper and filters.
LED sources often have discontinuous spectra, which can play poorly with paper that responds differently to different colours of light. A high CRI number doesn't solve the problem.
The glass carrier is, of course, one solution that does work.

 

[Pieter12]

Spectrum is also potentially a problem, if you are using multigrade paper and filters.
LED sources often have discontinuous spectra, which can play poorly with paper that responds differently to different colours of light. A high CRI number doesn't solve the problem.
The glass carrier is, of course, one solution that does work.

If the enlarger has a filter drawer, try a sheet of heat-absorbing glass in there.

 

[IMetodiev]

I'll second the glass in the filter drawer, it helped me

 

[Melvin J Bramley]

I'll second the glass in the filter drawer, it helped me

What glass did you use?

 

[ic-racer]

Let it pop, focus, cap the lens with the lamp on, place the paper in the easel, then quickly turn off the lamp, remove the lenscap and start the timer. This is standard practice with any enlarger that does not have a glass carrier.

A potential problem with a lamp that produces less heat is that it won't pop right away, so you will think the focus is stable, but during the exposure it will pop.