Print times tripled with color head vs condenser.

[rpavich]

im bummed.
I have been using a Beseler 23cii but wanted to experience printing with a diffuser so i got a Dual Dichro head and installed it today. To my disappointment My print times tripled using the same neg!

Example: With the condenser head I was printing a 4x6 using an 80mm lens with times of 15-25 seconds, now the dichro head the same setup takes 100 seconds!

To get anything reasonable for print times i had to switch to a 50mm lens and drop the head to within 10" of the easel.

Dang, what a disappointment.

 

[MattKing]

Something is wrong with your light path, because 15-25 seconds for a 4x6 is really long, and you should get the same exposure time with the 50mm and 80mm if you are using the same f/stop.

 

[Paul Howell]

double check to make sure you have the right bulb, the next thing is the voltage regulator, is it at the right output?

 

[rpavich]

double check to make sure you have the right bulb, the next thing is the voltage regulator, is it at the right output?

I checked, the bulb is correct. This one has the built in regulator.

 

[rpavich]

Something is wrong with your light path, because 15-25 seconds for a 4x6 is really long, and you should get the same exposure time with the 50mm and 80mm if you are using the same f/stop.

Well, let me be clear. I only changed to the 50mm to allow me to drop the head down in an effort to shorten the times.

Ill double check the light path

 

[bdial]

I don't know that head, but some (like the one on my LPL) have attenuators to optionally cut the light intensity without changing f/stops. If yours is so equipped, then you want to make sure it's set for maximum brightness.

 

[rpavich]

Ok....found the issues, all caused by me.

I used the hex cell diffuser from a "non-s" dichro head. The hole that the light comes through for the non-s is about half the size of the one for the S model.
Also, because of that, the diameter of the diffusion assembly is different by about 3/8 of an inch or so...they are certainly different.

I put on the proper conic light integrator and put the condenser unit from the 23S back in and got a printing time of 20 seconds, on par with the other head, not EXACT but certainly on par.

I guess now I go looking for the proper hex cell diffuser and diffusion assembly.

 

[MattKing]

Well, let me be clear. I only changed to the 50mm to allow me to drop the head down in an effort to shorten the times.

That shouldn't make a meaningful difference to the print time. If you enlarge a 35mm negative full frame to a 4x6, your magnification is the same (4X) whatever combination of lens focal length and enlarger height you use.
It may seem counter-intuitive but, for a given f/stop and image size, the light level at the easel from an 80mm lens set higher should be essentially the same as from a 50mm lens set lower.
The light level is a function of aperture and magnification. Magnification is a function of both height set and focal length. A change in focal length combined with the necessary change in height to give the same print size will leave you with the same result.
This inter-relationship will be screwed up if your light path is way out of spec.

 

[rpavich]

That shouldn't make a meaningful difference to the print time. If you enlarge a 35mm negative full frame to a 4x6, your magnification is the same (4X) whatever combination of lens focal length and enlarger height you use.
It may seem counter-intuitive but, for a given f/stop and image size, the light level at the easel from an 80mm lens set higher should be essentially the same as from a 50mm lens set lower.
The light level is a function of aperture and magnification. Magnification is a function of both height set and focal length. A change in focal length combined with the necessary change in height to give the same print size will leave you with the same result.
This inter-relationship will be screwed up if your light path is way out of spec.

Ok.
Thanks.

 

[DF]

Whenever I want to give my prints a "30-yellow fix", or minimize the already present contrast from alittle too-dense negatives (overexposure), it usually requires only a 1 - 1.5 stop adjustment from the original non-filtered print.
Might you have access to an Omega 3-Color Head Diffuser Enlarger?

 

[rpavich]

Whenever I want to give my prints a "30-yellow fix", or minimize the already present contrast from alittle too-dense negatives (overexposure), it usually requires only a 1 - 1.5 stop adjustment from the original non-filtered print.
Might you have access to an Omega 3-Color Head Diffuser Enlarger?

Nope.

 

[rpavich]

I've been scouring the internet to figure this out and found that when printing with a 35mm neg and the diffuser, the printing times shoot up to 2 or 3 times as long. I've also found that the recommendation is to get the diffuser for the 35mm negs (it's the same outside diameter but the diffusion glass is small, 2.5" or so in diameter) so I got one and it's on it's way.

FWIW, the machine works great in condenser mode.

So I'll keep on the lookout for an S model hex cell diffuser.

The extra springs and brackets would be nice, this thing is heavy!

 

[BMbikerider]

Enlarging a 6x4.5 neg to give a 12x16 b&w print with the colour head on my LPL7700 with a 80mm lens I very rarely have to go over 30 seconds. and for colour with RA4 paper it is about 12-16 seconds. Therefore I will go along with others there is something seriously wrong with your light source.

 

[rpavich]

Enlarging a 6x4.5 neg to give a 12x16 b&w print with the colour head on my LPL7700 with a 80mm lens I very rarely have to go over 30 seconds. and for colour with RA4 paper it is about 12-16 seconds. Therefore I will go along with others there is something seriously wrong with your light source.

Well, that's apples and oranges.
The point I was trying to make in the last post was that my experience isn't unique when using THIS particular head with THIS particular configuration of a full size diffuser and a 35mm neg, so you getting different results with a different sized neg and a different head isn't at all surprising.

Folks report that using this head with larger negatives in diffusion mode...the times are more "normal."

 

[mgb74]

I've been scouring the internet to figure this out and found that when printing with a 35mm neg and the diffuser, the printing times shoot up to 2 or 3 times as long. I've also found that the recommendation is to get the diffuser for the 35mm negs (it's the same outside diameter but the diffusion glass is small, 2.5" or so in diameter) so I got one and it's on it's way.
...

This is analogous to the diffusion chambers on Omega colorheads. You can use the 4x5 chamber with 35mm negs, but your exposure times will be longer.

 

[rpavich]

This is analogous to the diffusion chambers on Omega colorheads. You can use the 4x5 chamber with 35mm negs, but your exposure times will be longer.

Ahhh.
Got it.

Hopefully this means that I will be all set soon.

 

[ic-racer]

If changing lenses changes your printing times, something is wrong with the aperture of one of the lenses.

 

[DREW WILEY]

What on earth is the specific colorhead, mixing chamber, and diffuser are you are using? Colorheads generally use halogen bulbs which are much brighter than condenser systems.

 

[rpavich]

What on earth is the specific colorhead, mixing chamber, and diffuser are you are using? Colorheads generally use halogen bulbs which are much brighter than condenser systems.

Beseler Dual Dichro S head. Im putting it on a Beseler 23cII head.

Full size (larger than 35mm) mixing chamber

Do not have the proper diffuser yet.

I can tell you that the halogen bulb is insanely bright.

I can also say that just putting the diffuser mixing chamber in cuts about 4 stops of light as compared to the condenser.

According to Beseler, using the specific mixing chamber for 35mm negs restores several stops of light (the diffuser pane is only about 2.5" in diameter as opposed to the 5.5" diameter diffuser mixing chamber for larger negs.

 

[rpavich]

Ok....final post here.

I got a great deal on the 35mm mixing chamber and the "light tube" (which is a sheet metal thingy that fits down inside the 23c head to basically connect the diffuser to the mixing chamber so that no light is lost) and rigged it up tonight.
Well...color me very very pleased!
My times reverted right back to what they were with the condenser; no appreciable light loss!
It works awesome!

The only thing I'm missing from the set up is the extra spring and the extension handle for the adjuster that makes the lamp house go up and down but both of those I can do without as the lamphouse stays at the bottom of it's travel the whole time.

I owe a BIG debt of gratitude to member bdial (Barry Dial) who basically gave me the parts for the cost of shipping and made this possible...thanks Barry! I wouldn't have succeeded without you doing that for me.

 

[Arvee]

The red flag went up for me when you said your print times were 15-25 seconds for a 4x6 print. I use a 23CII with the standard 75W opal bulb to print 5x7 and I never have been over 10 seconds, typical is 5-8 seconds. Never goes over 12-14 seconds with an 80 lens and the appropriate head height for full frame 5x7. Sounds like you may have overly dense negs if your typical print time is 15-25 seconds for a 4x6 print with a stock 23CII. I think a problem existed before you switched to a color head.

Edit: I typically stop down 2-2.5 stops from max aperture. And, you are almost certain to get negative pop with 20+ seconds exposures with a condenser head unless you have a glass neg carrier.

 

[rpavich]

The red flag went up for me when you said your print times were 15-25 seconds for a 4x6 print. I use a 23CII with the standard 75W opal bulb to print 5x7 and I never have been over 10 seconds, typical is 5-8 seconds. Never goes over 12-14 seconds with an 80 lens and the appropriate head height for full frame 5x7. Sounds like you may have overly dense negs if your typical print time is 15-25 seconds for a 4x6 print with a stock 23CII. I think a problem existed before you switched to a color head.

Edit: I typically stop down 2-2.5 stops from max aperture. And, you are almost certain to get negative pop with 20+ seconds exposures with a condenser head unless you have a glass neg carrier.

Well...maybe I misquoted myself. I just did a bunch of 4 x 6's and the times were under 10 seconds.

In any case...everything is working great!