W.A. enlarging lenses ?

[Hilo]

Maybe a rather dumb question: does a W.A. Rodagon 40mm do the same as an EL Nikkor 40mm?

Or a Bogen W.A. 60mm, does it do the same as a Focotar 60mm? I am not thinking about contrast or sharpness, this is about coverage. Will they project the same size image, with the enlarger in the same place?

Some brands have the W.A. mentioned and that must mean wide angle. Others don't mention the W.A. Maybe with the latter it was assumed it speaks for itself?

 

[AgX]

To qualify as wide-angle lens, a lens must

-) have the respective focal length for the respective format

-) actually cover such wide angle, by yielding the repective image quality to the edges or even illuminate them at all and not be covered by the barrel


Thus one cannot necessarily take a lens dedicated as standard lens to a certain format and put it on a larger format as wide-angle lens.


Concerning your question:

The Rodagon 35mm is dedicated for 18x24mm (format diaganal 30mm), the Rodagon 40mm WA however already for 24x36mm (format diagonal 43mm).

However
The Nikon 40mm lens behaves as the Rodagon WA, but still got no wide-angle designation. Its wide-angle chraracteristic only is depicted in the Nikon lens broshure.

 

[Hilo]

Thank you AgX !

I understand it partly. Allow me to go more practical:

I am printing a half frame negative using a Focomat Ic with the 50mm Focotar. The paper size is almost 50x60cm, the image size a bit smaller.

The parallellogram is high up the column, I can barely use the grain focuser to focus but in the end the print turned out fine. Still, to focus is stretching my limits, so it makes me wonder which lens would bring down the parallelogram some distance (like 10 - 15cm).

I am not very good technically, but otherwise I know what I am doing and I have the feeling the 35mm will be too much of a drop. This is why I ask. In the mean time I can borrow the EL Nikkor 40mm from a friend, so I will try it.

 

[Lachlan Young]

I think the 35mm Rodagon was for 24x24 & the 28mm was for 18x24, but I could easily be wrong. They're both apparently good up to 30x with optimisation at about 20x - and most 40mm WA designs are usually recommended only up to 20x, so you might be pushing the performance envelope a bit on a WA-Rodagon at the size you want.

 

[AgX]

Yes, you are right, the figure of 18x24mm I named for the Rodagon 35mm was actually that of the Rogonar-S 35mm; I slipped into the wrong table
However this even more shows that at same focal lenght angle of coverage depends on design.

One thus must look up angle-of-coverage at the data sheets, as the focal length alone is not telling the whole story.

 

[Hilo]

Thanks Lachlan,

Olympus made an enlarger lens for their half frame system, a 38mm. Perhaps that is an indication.

I have made perfect 50x60cm prints from a 24x24 negative, using a Focomat IIc and it's 60mm. But again, to set it up is a challenge and I was on the limit of what is reasonable in terms of going up high on the column.

Anyway, I think we're not bound to an optimal focal length and if I could drop the enlarger about 10 - 15 cm, then I am okay.

 

[Hilo]

One thus must look up angle-of-coverage at the data sheets, as the focal length alone is not telling the whole story.

Yes, that is clear to me now. Thanks again.

 

[Martin Rickards]

If you look in the table on http://www.photocornucopia.com/1061.html there would seem to be offerings from Meopta, Minolta and Rodenstock at least for half frame negatives, which are all around 30 mm focal length.

 

[Hilo]

Thanks, yes I had seen the photocornucopia site !

For the EL Nikkor 40mm, does this tell anything?

 

[AgX]

Yes, look at the "Original size" as they call it. It is the diameter of coverage, thus just full frame.

This is what I meant by referring to it behaving as the Rodagon WA of same focal length.

 

[Hilo]

AgX, I understand but I am still not clear about the practical implication.

For instance, I get a perfect print using the Focotar-2 50mm (again, it is just not very easy to achieve and this is my reason for considering a different lens). So, isn't the Focotar even further away than the Nikkor 40mm from being correct for half frame?

My first prints from half frame negatives are from the beginning of the 80ties, and I have kept printing this negative size (next to many other negatives sizes) without a problem. But my largest size was 40x50cm. What is different now is that I have gone up to 50x60cm. Again, the prints I just did are fine and the same as their smaller earlier ones.

Perhaps I just need to get my hands on a couple of 30mm to 40mm lenses and make the same prints . . .

 

[Martin Rickards]

If you're unconcerned by the physical distance from your enlarger head to the printing paper, any good 50 mm lens will give you excellent results from half frame negatives. However if the enlarging distance is a problem, it can be eased by using a smaller focal length lens; either the typical 40 mm for full frame 35 mm negatives or a wader angle still designed to cover only the 18x24 mm format. There are several in the Rodenstock and Schneider listings of Photocornucopia and those with 6 element construction will be better than those with 3 or 4 lens construction. They are not that common however, but they will allow you to reduce the distance from the enlarger head to the paper by nearly 50%

 

[Hilo]

Martin, I do want the enlarger to drop down 10 - 15cm, because changing half frame negatives for the size I print is not very comfortable. But I would prefer to get a lens as close to 50mm as possible. I will just start and try a 40mm and, if needed, go down to 35mm and 30mm . . . But I suspect a (none W.A.) 40mm will be okay.

Thanks everyone, I will come back with the result !

 

[AgX]

AgX, I understand but I am still not clear about the practical implication.

For instance, I get a perfect print using the Focotar-2 50mm (again, it is just not very easy to achieve and this is my reason for considering a different lens). So, isn't the Focotar even further away than the Nikkor 40mm from being correct for half frame?

Yes, it is (or rather its optical center).

Being of shorter focal length the Nikkor will give more enlargement at same film stage height. Or the same scale at lesser height. The former is the actual reason for using it. And as it is designed optically and mechanically for this it even projects the full frame.

 

[Hilo]

Now I have a Zuiko 38mm enlarging lens coming which they made for half frame negatives. Here an info sheet about this lens . . .

 

[DREW WILEY]

Speaking in general, expect more illumination falloff towards the corners of any wide-angle enlarging lens, just like camera lenses. Not a good idea unless you're forced to do so due to limited enlarger column height. For smaller prints, the lens might end up too close to the easel for convenient dodging and burning. You'll obviously have to do more corner and edge burning-in with a wide-angle design lens. But in this case, since he's referring to half-frame, a 38mm lens would be classified as a somewhat "normal" focal length.

 

[Patrick Robert James]

Don't forget Hilo that you will probably need a shorter tube for the wider Olympus lens to get it to focus on the 1c.

 

[AgX]

In this context I do not untstand the use of the accesory extention ring delivered with that Olympus lens.

 

[Hilo]

Patrick, thanks ! Yes, I know this parameter plays. Had you understood this Olympus lens comes with a tube ? That metal coloured ring . . . Anyway, I have many Leitz made and non Leitz tubes in many sizes and in the end I always manage . . . (to remember is the major challenge, ha)

I also have a modified Valoy II that does 50x60cm (20x24in.) and with that everything is always easier.

Michael

 

[Hilo]

In this context I do not untstand the use of the accesory extention ring delivered with that Olympus lens.

For sure, not having the lens here, I can't figure that out. But I am sure I will once I can use it and try out different options.

 

[Hilo]

Thanks Greg !

Good stuff !!