Fellow APUGers, I need help :)

Kim Catton · Jun 16, 2007

This is going to be a tough one to explain, but here's my shot:

Im about to use my Krokus Enlarger for the first time. Im going to make prints of 35mm and 6X6. Im almost set. BUT.

I recon that one have to use a different condensator( is this what its called in english?)and a different lens depending on whether one is enlarging 35mm or 6X6. ?

ive got one which consist of 2 round glass elements and one which consist of 2 kind of oval/rectangular shaped glass elements.

Ive got one 50mm lens and one 90mm lens.

p.s. I just noticed that a piece of matt/frosted glass can be fitted between the lamp it self and the condensator. What is this for ? should I fit it or should I leave it be :O) ?

Hope this post is understandable. ANY help is much apreciated.

Regards, Kim

Fotohuis · Jun 16, 2007

It's called condensor and indeed some enlargers have smaller ones for higher intensity on the smaller negative format.
If your Krokus enlarger is equipped with the 6x6 condensor you can use it also for 35mm.

Use for the 35mm negatives the 50mm lens and for the 6x6cm negatives the 90mm lens. When doing the print, close the aperture 2F stops.
Sometimes you have to turn the lensplate for 180 degrees to get in focus for the 90mm lens. You need a concave lens adapter for these lens.

Kim Catton · Jun 16, 2007

Allright, which one is the condesor for 6x6 then ? the small round one or the big oval/rectangular one?

"close the aperture 2F stops" - I'm not quiet sure I understand this ?

What about the frosted glassplate between the lamp and condensor?

regards, kim

Fotohuis · Jun 16, 2007

The smaller one is for the smaller format.

For focussing open the aperture on the lens full (can be 2,8 or 4,0) depending on the lens. Then 2 clicks further for making the print to optimize your enlarger lens preformance (5,6 or 8,0).

The frosted glassplate can sometimes be used for the multi contrast filters, it's an extra diffusser to soften the light.

Maybe someone who is working with a Krokus (Polish) enlarger can give you some exact details.

Best regards,

Robert

Kim Catton · Jun 16, 2007

Thanks a lot ! I will soon be making the very first print

mikebarger · Jun 16, 2007

I suspect you will be happier using the 90mm for your 35mm than the 50mm.

Only problem is if you have enough column if you are making large prints.

Mike

Richard Kelham · Jun 16, 2007

mikebarger said:
I suspect you will be happier using the 90mm for your 35mm than the 50mm.

Why? The 50mm lens will give more than adequate coverage for 35mm negs it's what it is designed for, after all.

glbeas · Jun 16, 2007

The 50mm lens with the 6x6 condensor is a mismatch and will not give good even coverage of the light. Thats why there's two sets of condensors. Usually you will get a hotspot with the 50 and the 6x6 condensor set.

dancqu · Jun 17, 2007

glbeas said:
The 50mm lens with the 6x6 condensor is a mismatch ...

Not a best match. That is if 35mm negatives are being
enlarged. The intensity of light falling on a 35mm negative is
not so much as it could be were the smaller format condensers
installed. The 6x6 condensers cover any format up to 6x6 and
allow any lens focal length up to at least 90mm.

As for the 90mm with 6x6 condensers, it may make for sharper
prints from 35mm. The negative is center field with the 90.
Of course the projected image will not be so large. Dan

glbeas · Jun 17, 2007

dancqu said:
Not a best match. That is if 35mm negatives are being
enlarged. The intensity of light falling on a 35mm negative is
not so much as it could be were the smaller format condensers
installed. The 6x6 condensers cover any format up to 6x6 and
allow any lens focal length up to at least 90mm.

As for the 90mm with 6x6 condensers, it may make for sharper
prints from 35mm. The negative is center field with the 90.
Of course the projected image will not be so large. Dan

Theres more to it than intensity of light. A condensor doesn't act like a diffusion box, which acts the way you describe. A mismatched lens and condensor set may be trying to focus an image of the bulb as well as the neg image resulting in the hotspot in the middle. The other end of the spectrum you would be getting vignetting because the condensor doesn't cover the image area sucessfully. Either way the lens and condensors need to match either by changing condensors with the lens or changing the distance from the condensor set like the Beseler 45 series do. Sometimes the difference is so small it can be ignored but the possibilty is enough that you want to pay attention to whats happening in the light path.

Richard Kelham · Jun 18, 2007

The OP does have both sets of condensers, so the lens can be matched.

Fellow APUGers, I need help :)

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