Enlarger bulb power/negative size question

[haris]

Hi,

Is 150W enlarger bulb strong enough for 4x5 and 5x7 negatives? Or 250W is must? I mean, to have "normal" exposure times, not long ones.

What is "normal" enlarger bulb power for 8x10 negatives?

Thank you.

 

[Nick Zentena]

Condensor or diffusion? How good is the light box?

FWIW:

My Beseler 4x5 condensor head is 150watts tungsten
My Beseler 4x5 diffusion head is I think 200 watts of halogen?
My Durst 4x5 diffusion is 400 watts of halogen

The 150 watt condensor head is likely the most powerful of the two. The Durst the weakest.

It's not the size it's how you use it

 

[Donald Miller]

I converted my 5X7 to 1000 watt lamp.

 

[haris]

Thing is next:

Following information about Philips stopping manufacturing its enlalrger bulbs, I ordered "life supply" of them. I work with 35mm and 6x7 negatives for now. But, I seriously think about going LF. So, I think, at time when I start LF and buy enlarger (if 4x5 or 5x7 I will buy enlarger, 8x10 probably contact copying) will I be able to use bulbs I will have. So, it is general question, I don't know will enlarger be condenser or diffuser type, or anything else for now...

Thanks Nick and Donald for answer.

 

[Nick Zentena]

Don't worry about contact printing. You can always rig up something. More likely you'll want less light for contact printing not more.

 

[Vaughn]

The standard bulb for Omega D5's condenser light source for printing 4x5's is 75 watts (bulb PH211). Plenty enough light for 16x20 prints from 4x5 negs using the middle f/stops on a 135mm lens -- basic exposure times around 25 seconds for most Ilford papers.

Vaughn

 

[Bob Carnie]

This is true.
but I use a 250w bulb for more speed. granted I go through more bulbs but the speed is great.

The standard bulb for Omega D5's condenser light source for printing 4x5's is 75 watts (bulb PH211). Plenty enough light for 16x20 prints from 4x5 negs using the middle f/stops on a 135mm lens -- basic exposure times around 25 seconds for most Ilford papers.

Vaughn

 

[Roger Hicks]

This has always puzzled me. Bigger neg = more light going through and less enlargement. Logically, therefore, LESS power needed. I've never thought hard about it but I was surprised that my Durst 138 head used 2x 1000W.

Cheers,

R.

 

[Nick Zentena]

But smaller neg lets you focus the light more. Bigger neg you spread it out. That's my guess.

 

[Vaughn]

This is true.
but I use a 250w bulb for more speed. granted I go through more bulbs but the speed is great.

Assuming you are using a D5, are you use a piece of heat absorbing glass to keep the neg from baking? I know Omega recommends a piece if using a 150w PH212 bulb in the D5. The 250w seems like it would create a lot of heat the enlarger was not designed for.

Personally, I like working with exposures around 20 or 25 seconds...gives me a lot of time to evenly dodge and burn, and allows for finer adjustments of exposure times without worrying about fractions of seconds...while working at the sharpest f/stops of the lens.

Your milage may differ...

Vaughn

 

[Bob Carnie]

Andre Laradoe at DMax in Toronto and I both use the 250w without heat absorbing glass.
Between us we have made thousands of prints with the 250w on the D5's, just go through more bulbs. The speed is worth it.
10 Percent burn or dodge is exactly the same if you are using 10secs as main or 25secs as main.
I use the apeture closed down to 2stop or 3stops and find my printing times are generally around 10-15secs.
No problem to dodge and burn with this time.

Assuming you are using a D5, are you use a piece of heat absorbing glass to keep the neg from baking? I know Omega recommends a piece if using a 150w PH212 bulb in the D5. The 250w seems like it would create a lot of heat the enlarger was not designed for.

Personally, I like working with exposures around 20 or 25 seconds...gives me a lot of time to evenly dodge and burn, and allows for finer adjustments of exposure times without worrying about fractions of seconds...while working at the sharpest f/stops of the lens.

Your milage may differ...

Vaughn

 

[Jim Jones]

The light from many properly set up condenser enlargers is focused on the enlarging lens aperture, and projected onto the paper. Larger film is positioned closer to the condenser lens, smaller film closer to the enlarging lens. Since much the same amount of light reaches the paper, the size of the paper and the enlarging lens aperture control exposure more than the size of the film.

 

[haris]

Thank you all.