Support our Sponsors, they keep FADU free: AG Photographic The Imaging Warehouse Process Supplies RH Designs Second-hand Darkroom Supplies |
> Definitive Values |
*** Click here for the FADU 2015/2014 Yearbooks *** |
|
Thread Tools | Search this Thread | Display Modes |
#1
|
|||
|
|||
Definitive Values
Try as I may I cannot get an accurate figure for the colour temperature of a bulb used in a B&W condenser enlarger. It seems that it can be anything from 2800 to 3500 degrees Kelvin Has anyone else any closer estimates please. I should know this but I cannot find from where.
|
#2
|
|||
|
|||
Any sign of the colour temperature stamped on the crown of the bulb itself? Or any other identifiers?
Presumably it's a coated Opal lamp with a tungsten filament? Mike |
#3
|
|||
|
|||
I actually have not got one to check, I was hoping that someone could tell me.
|
#4
|
||||
|
||||
I don't know if this will help but I use Dr. Fischer and they're rated at 2800k.
__________________
MartyNL “Reaching a creative state of mind thru positive action is considered preferable to waiting for inspiration.” - Minor White, 1950 |
#5
|
||||
|
||||
A standard tungsten bulb has a colour temp of 2800 K.
Halogen bulbs are 3200 K. Of course their colour temperature can be changed by tinting of the bulbs glass. The tungsten bulbs used in B&W enlargers are special only in the fact that they are made to tighter tolerances than standard household bulbs. Martin |
#6
|
|||
|
|||
John.
Ollingers site has quite a few enlarger reviews, and if you click on the pdf icon on the first page it will give you access to a list of manuals for enlargers, camera, cine etc. Just a chance that if your enlarger is in the list it may have the lamp information amongst the specifications. http://www.jollinger.com/photo/enlargers/durst.html Cheers.
__________________
It will all be over by Christmas. |
#7
|
|||
|
|||
I just looked at a random enlarger on Ollingers manuals list,
VIVITAR V1 enlarger PH111A bulb. Could be a special bulb as it works on its side, but it appears to be tungsten and working in a condenser enlarger. Looking at a bulb sellers specification it says, PH11A 75w, 115-125v, 2900K, 1120 lumens 15 hours. So the bit I concentrated on is "condenser enlarger" ...."2900K." If you trawl through a couple of other manuals on the list you may find your enlarger or something similar. for confirmation. Before I knew about colour temperature etc. i used to buy whatever bulb Woolworths had in stock and rub off the printing with a Brillo pad pan scourer. Simple happy days. Cheers.
__________________
It will all be over by Christmas. |
#8
|
|||
|
|||
I used to work in the lighting industry and I searched published literature in vain for the colour temperature of typical enlarger lamps.
Basically, the lifespan of a tungsten filament in an evacuated globe is defined by the temperature at which it is operated. I learned that domestic lamps would last 1000 hours at 2900K, 275W 'Photoflood' lamps would last 10 hours at 3400K. But I also found that several manufacturers quoted the lifespan of 75W and 150W enlarger lamps as 100 hours. Then I searched for other tungsten-filament lamps with quoted 100 hour lifespans. and found the bulbs used in 'studio lamps', typically 250W, 500W and 1000W, all of which have a colour temperature of 3200K. From the 1960s onward Eastman Kodak gave suggested exposure times for Ektachrome type 'L' sheetfilm and a colour temperature of 3200K. So I reckon that enlarger lamps from Philips, Osram &co run at 3200K. |
#9
|
|||
|
|||
I've just read the file Dr.FS-146.pdf from Marty NL, which I had not studied and which gives a figure of 2800K. But with a remarkably short filament life.
|
#10
|
|||
|
|||
I suppose the most accurate way is to use a colour temperature meter and see what they say. I cannot say I have ever used or even seen one.
|
Support our Sponsors, they keep FADU free: AG Photographic The Imaging Warehouse Process Supplies RH Designs Second-hand Darkroom Supplies |
Thread Tools | Search this Thread |
Display Modes | |
|
|
Similar Threads | ||||
Thread | Thread Starter | Forum | Replies | Last Post |
Agfa and Kodak enlarger filter values | IainHC | Darkroom | 16 | 9th February 2016 02:02 PM |
Narrow Exposure Values | Nabhar | Monochrome Film | 15 | 23rd August 2012 04:18 PM |
The Definitive Guide | Richard Lee | Books | 3 | 31st May 2011 10:25 AM |
Film v Digital Values | cliveh | Photography in general | 15 | 12th May 2011 09:59 AM |
Differing print values. | Nabhar | Monochrome Film | 11 | 16th January 2011 05:42 PM |