Replacing an enlarger bulb with a LED bulb

[Steve M.]

I have a small Federal model 135 enlarger that arrived with the bulb broken during shipping. The replacement bulb is nearly $10. It's very small for an enlarger bulb, about the size of a ping pong ball, and sits over an optical glass on top of what must be the world's smallest condenser (this model only enlarges 35mm negs, so I guess they never saw the need for anything bigger). This is what it looks like. My fingers are there in the second photo to give some scale to this.

My question is: Shouldn't any bulb that is 50 watts and the right voltage work as long as it's small enough to be centered over the condenser? My mind keeps thinking that an incandescent bulb will give crisper negs than an LED bulb w/ a condenser enlarger. That may be just a hunch though. The enlarger's manual calls for a 125V bulb, but good luck on that in 2019. 110V should be fine.

 

[Ko.Fe.]

LED works in enlargers.
https://www.photrio.com/forum/threads/using-off-the-shelf-led-bulbs-in-an-enlarger.111202/
Where are dimmable LED bulbs as well.

 

[Steve M.]

I was just on that site, but in a different place. They didn't seem to think it was a good idea on a Focomat because everything was scaled down into a small package. Just like my Federal. Except that my Federal is a Dollar Tree version of a Leitz enlarger. Still, I've gotten good prints from these. At some point w/ any enlarger you have to ck everything to see if it's level, square, doesn't leak tons of light, all that.

https://www.photrio.com/forum/threads/replacing-12v-75w-enlarger-bulb-with-led-upgrade.122743/

 

[Rob-F]

I think it would just be a matter of whether the LED emits about the same spectrum as an incandescent. I notice that different LEDs differ in their spectral output. Some are "daylight" while others are described as "warm" and so on. It would especially matter with variable contrast papers!

 

[mcfingon]

I think it would just be a matter of whether the LED emits about the same spectrum as an incandescent. I notice that different LEDs differ in their spectral output. Some are "daylight" while others are described as "warm" and so on. It would especially matter with variable contrast papers!

Supporting what Rob-F says, I use an LED globe in my Opemus II enlarger which is dedicated to scanning with a DSLR. I get a warmer than neutral tone from the scans which I dial out when I'm processing the scan on the laptop. This would make Ilford Multigrade paper more contrasty than standard I believe, although probably not a huge difference. John Mc

 

[ChrisPlatt]

Why mess around?

Why mess around?

Buy two $10 original replacement incandescent bulbs.
That should be a lifetime supply.

Chris

 

[titrisol]

I have been using a Warm White LED (2700K) which should give a similar spectrum as an incandescent and it works fine
However my timer (GRALAB 450) has aged, and I think it needs recapping. The LED flickers when it is supposed to be off.
What I learned from this is to buy dimmable LED bulbs which have some extra circuit and dont flicker.

 

[ddutchison2]

Why mess around?

Why mess around?

Buy two $10 original replacement incandescent bulbs.
That should be a lifetime supply.

Chris

A couple of reasons why could be that (on account of LED's running far cooler that incandescence's) negative popping from heat expansion ceases to be a problem. On enlargers without dedicated filter drawers, LED's allow you to just drop a filter gel on top of the condenser - a much better option than holding one in front of the lens.

 

[Mos6502]

I've used LED bulbs with varying results in an enlargers. I have two old Federal enlargers both of which work well with LED bulbs, in the larger one, there's a diffusion screen over the condenser lens, and the smaller one is diffusion only. This is fine. In my Spiratone enlarger which works with a double condenser, LED bulbs cause hot spots and no amount of repositioning the bulb or trying to change its focus eliminated them. In my Durst F60 the LED bulbs worked ok with 35mm, but had a noticeable vignette with the 6x6 holder and condenser (for that matter even the proper incandescent bulb is a real pain to get properly set up and illuminating evenly).

I have noticed the LED bulbs did result in slightly different contrast than usual, but nothing which wasn't easily overcome through the use of split filtering.

 

[x-ray]

Don’t feel bad about $10 for a bulb. My Durst Laborator 138 takes a special Osram bulb that’s been out of production for years. If you can find one it’ll set you back $400 or more. The 138 is a 5x7 enlarger and the bulb is quite large and opal glass. I tried similar bulbs about the same size but could never get the illumination even. It’s a reflex type housing that reflects the diffused light 90 degrees and through the condensing system. I wound up buying a 6x6 inch LED panel that’s 3400K and very even in illumination. I installed it where the bulb used to be and it works perfect. Illumination is even, it runs cool and my contrast grades seem to be very close to what they were with the incandescent bulb.

I have a Focomat 1C also and couldn’t find a 211 or 212 bulb that was even in illumination. The new manufactured bulbs aren’t equal in quality to ones from 20 years ago. I wanted to convert it to diffusion with a multi grade system but wound up buying an Omega B700 color head and adapted it to the Focomat. Works perfect and I can dial in my contrast filters.

 

[someonenameddavid]

Don’t feel bad about $10 for a bulb. My Durst Laborator 138 takes a special Osram bulb that’s been out of production for years. If you can find one it’ll set you back $400 or more. The 138 is a 5x7 enlarger and the bulb is quite large and opal glass. I tried similar bulbs about the same size but could never get the illumination even. It’s a reflex type housing that reflects the diffused light 90 degrees and through the condensing system. I wound up buying a 6x6 inch LED panel that’s 3400K and very even in illumination. I installed it where the bulb used to be and it works perfect. Illumination is even, it runs cool and my contrast grades seem to be very close to what they were with the incandescent bulb.

I have a Focomat 1C also and couldn’t find a 211 or 212 bulb that was even in illumination. The new manufactured bulbs aren’t equal in quality to ones from 20 years ago. I wanted to convert it to diffusion with a multi grade system but wound up buying an Omega B700 color head and adapted it to the Focomat. Works perfect and I can dial in my contrast filters.

What is the make and model of your 6x6 array or what website. Theoretically LEDs should give sharper images because they have narrow bandwidth emissions and lenses can focus them more precisely but I digress

 

[Deleted member 65559]

Don’t feel bad about $10 for a bulb. My Durst Laborator 138 takes a special Osram bulb that’s been out of production for years. If you can find one it’ll set you back $400 or more. The 138 is a 5x7 enlarger and the bulb is quite large and opal glass. I tried similar bulbs about the same size but could never get the illumination even. It’s a reflex type housing that reflects the diffused light 90 degrees and through the condensing system. I wound up buying a 6x6 inch LED panel that’s 3400K and very even in illumination. I installed it where the bulb used to be and it works perfect. Illumination is even, it runs cool and my contrast grades seem to be very close to what they were with the incandescent bulb.

I have a Focomat 1C also and couldn’t find a 211 or 212 bulb that was even in illumination. The new manufactured bulbs aren’t equal in quality to ones from 20 years ago. I wanted to convert it to diffusion with a multi grade system but wound up buying an Omega B700 color head and adapted it to the Focomat. Works perfect and I can dial in my contrast filters.

I also have a Durst 138 (5x7") with a colour head. I've only blown the bulb once. Mine takes a common bulb that was used for slide projectors.

 

[OmegaB600]

the main bain according to all of the reliable sources on LED bulbs is that, although the bulbs will last..


The bulbs are not identical with each other from batch to batch. Thus if you have to replace one, even if you get an identical model bulb, it wont be the same.

The real means now for LED based is either qa company in germany

Heiland electronic GmbH, Wetzlar / Germany - 6x9cm

making your own LED head, which is hard because most suppliers of LED diode deelies arent exactly truthful on what they are selling..

Or converting the whole rig to use an elarger kit panel from Entrepid