lens for Beseler V-XL 8x10 "conversion kit" enlarger

[nicholas_f._jones]

The Beseler 8x10 V-XL enlarger is equipped with a �conversion kit�

that permits enlargement of an 8x10 negative at a distance to the

easel much shorter than in the conventional design, so a lens of

shorter focal length than normal for this format is required.

Beseler sells the 240mm apo-gerogon, but this lens has been

repeatedly criticized in previous threads (esp. on the point of light

fall-off and the small aperture at which it is optimized). My

question is whether other 240mm enlarging lenses (e.g. Schneider 5.6

componon-s and Rodenstock 5.6 Rodagon) are interchangeable with the

lens offered and apparently preferred by Beseler.

 

I wonder this because in the Rodenstock line, enlarging lenses of the

same focal length are designed for different size printing�that is, I

guess, their optimal focus is at varying distances from the

negative. So the 240mm/5.6 rodagon-G is for printing murals and

would not be appropriate for 16x20 or 20x24 work on the V-XL. Now,

is the same true of the 240mm apo-gerogon vs. the Schneider 240/5.6

componon-s and Rodenstock 240/5.6 rodagon? Do the latter two lenses

focus at a point suitable to the shortened column of the V-XL?

 

While we�re at it, I have similar concerns about 5x7 printing on this

enlarger. Would a lens of the usual focal length for this format,

180mm, but intended for a conventionally designed enlarger be

suitable for the V-XL �conversion kit� configuration? Thanks in

advance for any replies.

[light-zone]

I've got a Durst 138S and the "standard" focal length for 5X7 is 240mm. It's a condenser enlarger, so the proper use of the condersers will determine the lens coverage and light falloff, as well as the lens to easel distance.

[bob_salomon]

Thae Apo Geragon is not an enlarging lens and will perform nowhere as well

as the Rodagon. The G will not work at all.

 

The only reason they put the Apo Geragon process lens on the enlarger is

that it fits their lensboard. The Rodagon is a larger thread.

 

So fit the board - make lower quality prints (optimal aperture is f22).

 

Make an adapter and use an enlarging lens and get far better prints over a

wider range of magnification and at a wider range of apertures.

 

Or buy an 8x10 enlarger.

[bob_salomon]

Some further info.

 

The Apo-Gerogon is corrected for 1:5 (1/5th lifesize to 1:1 (lifesize). And

optimal aperture is f22

 

The mount size is 50mm.

 

The 240 Rodagon is corrected for 2 to 8x magnification from about 11/2 stops

down to about 3 stops down (F9.5 to 16) much more practical then f22 and

less likely to put you into reciprocity failure.

 

The mount size is 72mm.

 

The Rodagon G is corrected for 8 to 30x magnification (far more then your

enlarger can do) and would not equal the Rodagon at the magnifications you

can do.

 

It is designed to be used 1 to 2 stops down.

 

There were no Apo Rodagon enlarging lenses for formats larger then 4x5".

Apo Rodagon lenses longer then 180mm were process lenses and not

enlarging lenses. So the 240 Rodagon would also outperform them.

[eric_boutilier_brown1]

I use a 240mm f/9 G-Claron on my 8x10 enlarger, and it works wonderfully. With my Aristo cold-head, it is plenty bright to focus with, and most of my exposures are at 10-15 seconds at f/22 - 32, so you stop down and get plenty of coverage. I have made prints from 4"x5" to 24"x30" from this lens, and the results are excellent - and I got it for $99 on e-bay, so it is not expensive used.

[bob_salomon]

"the results are excellent"

 

There is no question that you may be satisfied. But have you ever made side

by side prints from the same negative with an enlarging lens and compared

them?

 

results isolated from valid comparisons can be very misleading.

 

And then the results that you get may not please someone else.

[kevin_kolosky]

For once in my life I agree with Bob. Its kind of like buying a warm pair of boots for the winter. to test them, if you wear one pair one day and wear another pair another day, you will not now the difference. but if you wear one boot on one foot and one boot on the other foot you will know the difference. Translation: As Bob says, set everyting up. same neg, same chemistry, same paper, same everything. only have one variable which is the two lenses you are going to test. then and only then will you know the difference.

 

Kevin

[eric_boutilier_brown1]

Hi Bob, Kevin,

I agree that comparison is important, and that image quality is to a high degree subjective.

 

In regards to the testing, while I don't have a second lens that covers 8x10, when I first considered the G-Claron, I did a comparison between it and the 150mm Componon-S I use to print 4x5 film. I enlarged a 4x5 section of an 8x10 neg with the Componon-S, and matched the enlargement with the G-Claron (on the same enlarger, as I hadn't my 8x10 enlarger yet). Comparing the two images side by side, I could see no perceptable differences. The only difference was the lens - paper, filter, and chemistry was all the same. I tried as hard as I could to make them match, and once they were toned, dried and flattened, I could not tell which was which without checking for the mark on the back. That was good enough for me. I have no doubt that a 240mm enlarging lens would be technically better, but I do wonder if a) it would perceptable and b) worth the cost differential.

 

e.

[bob_salomon]

"Comparing the two images side by side"

 

Edge, center, corner?

[neil_poulsen1]

I had a problem finding a 240mm lens small enough to fit my 8x10 enlarger. I was able to easily fit a recent Zone VI 8x10 onto my early Zone VI Type 1 enlarger. But, the Type 1 has lens stage that's too small for many of the enlarging lenses currently for sale.

 

I found an older (70's?) Schneider Componon 240mm enlarging lens that's smaller and fits just fine. The rear element is about 2 3/8 inches in diameter.