I'm refurbing some Meopta Axomat enlargers for a school, and the 150w bulbs they use are expensive and hard to find, so I was wondering if anyone had recommendations for LED bulbs I might use in them? This old thread:
There are many out there still using enlargers taking the traditional opal PH140 or #211 bulbs. I wonder if those people are aware of a 50 cent replacement? Today, I went to the chain "DollarTree" and bought a package of two (Sunbeam brand) LED 60W equivalent bulbs for only $1, total. Just...
I have a Axomate that I use with a standard GE LED bulb, it does have a bit of afterglow, the afterglow does not last long and faint not enough to create issues when making test strips. Freestyle has 150 watt bulbs at $5.99 each, which is less than a GE LED bulb from a big box store like Lowe's. Not sure if you can get bulbs as cheap as in the post you found, but still inexpensive on Amazon, LED 60 watt replacement is $7.98 while a 100 watt is $15.98 cheaper if you buy a 4 pack. I still use 75wat and 150 watt enlarger bulbs in my D3.
I think a real tungsten filament incandescent lamp is still the best choice. If you can get a genuine 150W (PH 212 ?) great, I think you could try any "soft white" type frosted bulb..
MHOFWIW
Same-ish as Paul Howell here. Using a cheap 11W warm white LED bulb in my Opemus 5 with Ilford under-the-lens filters and I'm pretty happy with the contrast range it allows for.
Exposure times are a bit on the short side, but that's by choice as I could have taken a lower wattage bulb instead but need the light output for when I do lith printing which needs much more light.
No issues with afterglow though. 4x 1sec give the same result on paper (at least to my eye) as 1x 4sec.
My bulb looks like the OSRAM in your link in terms of construction/shape, although mine is a different (local chainstore) brand.
I had mixed results using frosted LED bulbs in my little durst f30. On the one hand, the contrast range it gave me was reasonable and the fact that the enlarger didn't even get warm to the touch was super nice.
On the other, I did end up going back to an incandescent bulb because no matter which LED bulb I tried, I ended up getting weird hot spots in the image. It was especially bad with the style of bulb that uses the "filament" style LEDs.
I did some tests with LED bulbs a few years ago and the found that a color temperature of at least 4000K was needed to get all contrast grades. But this was a few years ago, it may well be that nowadays LED bulbs are different.
Others have found the same, my negatives are scaled to print grade 2, not very often I print beyond 2 1/2 sometimes grade 3. I only use grade 5 when split grade printing.
The short answer to the original question (MHOFWIW) is nope, nothing new to report on alternatives to standard bulbs for enlargers.
For most of us no reason to substitute. Leds can be made to work, I've never fiddled with it.
Other than in my Chromega enlarger (which takes a silly bulb), I've only been using cheap (think dollar-store cheap) LED bulbs for several years. I haven't had any concerns about it.
When I tried this with my LPL 7700, I was constrained by the available power options for the bulbs that would fit and were available at moderate cost.
So prints from 35mm often required inconveniently longer exposure times.
The results though are good, and the lower heat is an advantage.
The contrast behavior is a bit different though - I use an LPL variable contrast head mostly on the enlarger, and the "grade" spacing is quite a bit different.
I've gone back to the 100W 82V halogen bulbs, but the 50W 82V bulbs I tried remain as a vary usable backup.