Replacing enlarger lamp with LED lamp - color temperature n brightness matter?

[sfoto100]

hi

with help from wootsk, i bought a LED lamp (brand is Megaman), from its specs in
MEGAMAN® | LED MR16 (ER1006-35H24D) - LED Reflector – Products | LED Lighting, LED Retrofit Lamps, Shop lighting, Direct Replacement for Halogen Lamps, it states:

Lumen Output: 240lm
Max. Lumen Intensity: 1,300 cd (which i take it to be 1300 candela)
Colour Temperature: Warmwhite (2800K) (it means 2800k color temperature )


My original lamp in the Durst 1200 enlarger uses General Electric ELC 250W 24V lamp, I found out that its spec is:

brightness is 800 lumens
color temperature: 3400 Kelvin



My question is does the color temperture matters? What difference will I notice and what should I take note of?

As for the change in luminosity, I guess it could only mean longer development time if my new lamp is not as bright. It should not have any other issues right?

tks alot

 

[yqt]

The change in color temperture of the bulb will also mean a change in the contrast of your print. Do a test and you should be able to see the difference between the LED buld and your previous bulb.

 

[sfoto100]

The change in color temperture of the bulb will also mean a change in the contrast of your print. Do a test and you should be able to see the difference between the LED buld and your previous bulb.

Hi tks alot

do you know off hand if it will result in less or more contrast? should not be a big issue right ? i just hate the heat and the high power consumption of the 250w lamp.. so i didn't buy it (yes it is still available)

i have only done one print session with my old lamp and it died. I have zero darkroom experience actually..

 

[yqt]

You may also need to look at how the buld distribute the light, is the light distributed evenly, any hotspot or shadow?. I also notice that the LED buld have a 24° beam angle which may affect the light distribution as well.

 

[yqt]

Hi tks alot

do you know off hand if it will result in less or more contrast? should not be a big issue right ? i just hate the heat and the high power consumption of the 250w lamp.. so i didn't buy it (yes it is still available)

i have only done one print session with my old lamp and it died. I have zero darkroom experience actually..

If I remember correctly, there will be a drop in contrast level.

You may also want to consider that the specs sheet did mention that the surface temp. is 100°C and also how will switching "ON" and "OFF" very often during printing affect the LED bulb.

 

[sfoto100]

If I remember correctly, there will be a drop in contrast level.

You may also want to consider that the specs sheet did mention that the surface temp. is 100°C and also how will switching "ON" and "OFF" very often during printing affect the LED bulb.

oh i didn't notice the 100°C surface temp. the shop people told me this is not as hot as the GE one.. i guess i am in trouble ..

i saw a higher color temp. version from the web, maybe i should change it to that one.. bcos there is a limit on on treaking the negative during development time.. i am using a color head, which means i can utilise the diff grades of the multi grade paper, but i would like to try printing just on normal contrast paper as advised in The Negative..

 

[yqt]

oh i didn't notice the 100°C surface temp. the shop people told me this is not as hot as the GE one.. i guess i am in trouble ..

i saw a higher color temp. version from the web, maybe i should change it to that one.. bcos there is a limit on on treaking the negative during development time.. i am using a color head, which means i can utilise the diff grades of the multi grade paper, but i would like to try printing just on normal contrast paper as advised in The Negative..

IMO, if you're using color head, better to stich to what the specs order least if the bulb is too hot, you may end up burning/warping your CMY filters.

 

[kgston]

I read the spec sheet in your link and it states for the Lumen output: 240lm which is far lower than the 800lm the original bulb produces. The last I saw (in best denki), a 6W LED MR16 type bulb is only equivalent to a 25W halogen bulb. When I saw your post I was surprised you could use replace a halogen bulb with a LED so easily as I read that normal electronic transformers cannot support the low wattages used by LEDs as they don't draw enough power for the transformer to work. Plus it also says that the bulb is 12V? it works on a 24V supply? I also have been wanting to swap my 100W halogen bulbs out for LEDs for a long time but have held back due to these issues.

 

[sfoto100]

I read the spec sheet in your link and it states for the Lumen output: 240lm which is far lower than the 800lm the original bulb produces. The last I saw (in best denki), a 6W LED MR16 type bulb is only equivalent to a 25W halogen bulb. When I saw your post I was surprised you could use replace a halogen bulb with a LED so easily as I read that normal electronic transformers cannot support the low wattages used by LEDs as they don't draw enough power for the transformer to work. Plus it also says that the bulb is 12V? it works on a 24V supply? I also have been wanting to swap my 100W halogen bulbs out for LEDs for a long time but have held back due to these issues.

hi

i bought a new transformer also.. so i am by passing the Durst circuit altogether...

i suppose you want to change your enlarger lamp also?

 

[sfoto100]

IMO, if you're using color head, better to stich to what the specs order least if the bulb is too hot, you may end up burning/warping your CMY filters.

hi

i call that shop again, he assured me that it won't be hotter than halogen lamp.. there is a heat sink at the back of the LED lamp, he said that part is hot, but if you place your hand in front of the LED lamp, you won't feel the heat.

hmm.. i also not sure if it will damage the CMY filters.. ;p

 

[sfoto100]

learn quite a few things about color when you got problem.. can i turn my 2800k color temp. LED light into a 3400K by utilizing the CMY filters? I got no idea, but i found this

Mired Shift Calculator for LEE Lighting Filters

and I need to apply a -63 mired to convert it to 3400k.. but no such filter then..


another question is, Durst 1200 uses this 3400k lamp, how about other enlargers? Are all enlargers using 3400k lamp?

using 2800k light will turn my multi graded paper into what grade?

so many questions..

the search continues.. if you have any ideas, pls feel free to contribute

 

[paapoopa]

I am using dunco enlarger with a philips halogen bulb which i think is 12V 50W and around 3000k color temp.
I am also thinking about the same issue just last week. haven got any answer yet though.
will be hear any old timer here can give any advice.

 

[kgston]

hi

i bought a new transformer also.. so i am by passing the Durst circuit altogether...

i suppose you want to change your enlarger lamp also?

Its for my drum scanner actually.. but i need the light output to be high, otherwise the PMT tubes cannot catch the light source.. i guess for enlarger not too bad? just expose longer.. haha

 

[sfoto100]

I am using dunco enlarger with a philips halogen bulb which i think is 12V 50W and around 3000k color temp.
I am also thinking about the same issue just last week. haven got any answer yet though.
will be hear any old timer here can give any advice.

hi

i will try printing these few days.. just need time to buy plug and wire..

i saw people using LED, and some even use color LED to achieve diff paper grades.. but they say it is difficult to achieve beyond grade 4 paper.. but Ansel Adams said in The Negative that for better pic, use normal contrast paper.. so this is why he uses zone system to achieve an optimal negative.. i am posting another thread to ask this question on paper grade. will post in largeformatphotography too.

hopefully i get something useful and then you can change to LED too... it saves the Earth as it release less CO2 and uses less power.

 

[paapoopa]

hi

i will try printing these few days.. just need time to buy plug and wire..

i saw people using LED, and some even use color LED to achieve diff paper grades.. but they say it is difficult to achieve beyond grade 4 paper.. but Ansel Adams said in The Negative that for better pic, use normal contrast paper.. so this is why he uses zone system to achieve an optimal negative.. i am posting another thread to ask this question on paper grade. will post in largeformatphotography too.

hopefully i get something useful and then you can change to LED too... it saves the Earth as it release less CO2 and uses less power.

hahaha, thanks thanks,
I will also see if I can find some answer to your questions.

 

[sfoto100]

hahaha, thanks thanks,
I will also see if I can find some answer to your questions.

hi

i fix the lamp and the image is very very very dim.. i didn't make any print as i am really tired and got tons of things to do... but i suspect i won't be able to focus given the dim image projected..

 

[paapoopa]

so your new LED light is not as bright as your halogen ones?

if it is very dim even when your lens is wide open, than when you stop down your lens to start printing, it will take really long wait to do 1 print.

 

[sfoto100]

so your new LED light is not as bright as your halogen ones?

if it is very dim even when your lens is wide open, than when you stop down your lens to start printing, it will take really long wait to do 1 print.

exactly.. which is another problem..

anyway i wil epxlore using my Sinar to print.. but need another LED.. zguy did one.. will consult him

 

[zguy]

aiah my is DIY solution which I prototype ..using a 4x5 cam as an enlarger will present its own set of problems like how to control contrast, how to prevent light leaks and spill. I have not further work on it since the last test.hhaa

A proper enlarger will work better. If you can get original bulb, then why not continue to use it? Just put a standing fan nearby too cool it down if its cooling system is not cooling it well enough. maybe considering getting a portable aircon.

 

[losheng]

hopefully i get something useful and then you can change to LED too... it saves the Earth as it release less CO2 and uses less power.

Using it in enlarger aside, LED lights are far less rosy as they are marketed to be. In general, LED lights have lower lumens, thus to maintain the same lighting level, you would need to double or triple the installations. If the street lamps were to switch to LEDs, then LTA will need to double the number of lamp posts to maintain the same lighting level. If you consider the cost and materials of these additional installations, it is not totally clear that switching to LED lights is any 'greener'. LED installations needs to be planned from the ground up. It's not a case of merely replacing each light with a LED lamp.

In Photokina, I saw an company that makes LED based variable contrast enlarger heads. It's a much larger module than the usual lamp housing. These modules are compatible with a wide range of enlargers. So if you want to go the LED way, that's probably the way to do it. However, I suspect the module will cost multiple times of what you pay for your enlarger!