610mm De Golden Busch VS Schneider 550 XXL

[sanking]

I have the 550 Schneider XXL and it is a fantastic lens. It is a Dagor type lens but designed to give better coverage on the edges than traditional Dagors. It will cover 20X24 with quite a bit of movement. It is multi-coated and has exceptional contrast.

Although I have never used the 610 Golden Busch my guess is that the Schneider is a better lens, but in ULF the difference is not likely to be relevant.

Sandy King

Which is better for ULF? The Golden Busch seems like a more complicated plasmat design. Would it be sharper at larger apertures then the XXL? How about the differences in light fall off? ...Shouldn't the plasmat have more even illumination?

[IanG]

Melles Girot made the Golden Busch lenses, I think.

The company is actually "Melles Griot" the misspelling seems to be in all the references to the Golden Busch lenses.

It would be interesting to know where the design came from, perhaps someone in Rochester has various lens designs tucked away. It's noticeable the lenses are always in Rochester made shutters.

Ian

[Dan Fromm]

Ian, Melles Griot is a successor to Ilex. I haven't checked for a while, but I believe that MG still offers Ilex electronic shutters with, of course, its own name on them.

About the de Golden-Busch lens' element count, I think there are three pieces of flat (or nearly) flat glass in it.

[IanG]

Thanks Dan, I assumed it was something like that. Yes they do still make & sell electronic shutters.

Your also right the diagram of the de Golden Busch does appear to have flat glass in it, very strange.

Ian

[Tracy Storer]

I don't know about sample to sample consistency, but the 610 de-Golden Busch I used did not cover 20x24 generously...if I remember correctly, at least illumination (if not sharpness as well) suffered around the edges when we used it near infinity.
The Schneider 550 XXL sounds great, I would love to try one some day. (I use a Fuji 600-C which is very good.)

http://cgi.ebay.com/de-Golden-Busch-...QQcmdZViewItem

For what it's worth, the seller claims coverage of 20x24.

[aduncanson]

To further over-interpret a vague technical drawing, notice that there are also ray tracings depicted. (http://www.superlarge.com/deGoldenBusch/index.html)

Those three "flat or nearly flat" elements also do not refract the rays detectably. Even if flat, there should be refraction of oblique rays at the interfaces. Therefore these elements are not only flat, but they have a refractive index very close to air - even more strange.

[GPS]

To further over-interpret a vague technical drawing, notice that there are also ray tracings depicted. (http://www.superlarge.com/deGoldenBusch/index.html)

Those three "flat or nearly flat" elements also do not refract the rays detectably. Even if flat, there should be refraction of oblique rays at the interfaces. Therefore these elements are not only flat, but they have a refractive index very close to air - even more strange.

There are no three "flat or nearly flat" glass elements in the drawing, just 4 glass elements.

[8x10 user]

Perhaps there are 7 elements in 4 groups? The design looks like a Sironar to me, but the curvature of the elements seems more extreme. Maybe the extra element was required to produce such deep curves. Diagram of a Apo-Sironar-S

[8x10 user]

How does the 550 XL perform wide open?

[GPS]

Perhaps there are 7 elements in 4 groups? The design looks like a Sironar to me, but the curvature of the elements seems more extreme. Maybe the extra element was required to produce such deep curves.

8x10, your pink drawing is not the same as the one in the link. Anyway, there is no perhaps about the number of elements in the drawing - technical drawings are clear enough (they have to be) to see it.