Busch Nicola Perscheid ?

[CCHarrison]

Hmmmm... Kingslake diagram attached....

Dan

[Jim Galli]

Jim it is a Triplet and next time I am in my country blues house I will perform some home made surgery and show you an inside view!
Three large glass air spaced!

Hmmmm... Kingslake diagram attached....

Dan

Anxious to see that. Always willing to learn there's something weird I haven't seen yet. Please do some pictures of it when you can. Thanks! Jim

[Stephane]

I have a 480mm too and it is like on the diagram above.

[CCHarrison]

This Japanese page mentions (via google translate) a few Perscheid lens types... it also mentions the 4 element symmetrical design as shown above, but also that many versions were a "triplet pattern type."


http://blog.goo.ne.jp/finephotograph...931a50db2d91ae

So, it appears everyone is right !! Now, someone needs to compare the 4 element against the 3 element

Below are images of the Perscheid "Portrat Objektiv" and the regular, Perscheid "Objektiv"

I assume/guess the Portrat Objektiv may have 3 elements and the regular Objektiv 4...

Dan

[community1313]

Anxious to see that. Always willing to learn there's something weird I haven't seen yet. Please do some pictures of it when you can. Thanks! Jim

i did send the photos to Jim and yes it is a triplet,

[community1313]

Voilà, the two front and back lens are shown and the middle one is hidden between the aperture blades..It's a beast, to big to be mounted on a sinar, it needs a studio wood camera..

[community1313]

The inside lens..

[Nathan Potter]

i did send the photos to Jim and yes it is a triplet,

Interesting triplet. Is it possible that the center element is negative and simply used to increase the focal length of the basic doublet without appreciably changing the dimensions of the housing? Something like the early Dallmeyer Triple Achromat. Such a negative element might still preserve the soft aspect of the lens and not appreciably improve the degree of spherical correction.

Nate Potter, Austin TX.

[carverlux]

Some facts:

1. My 42cm Nicola Perscheid is a doublet/RR. It has very little residual CA and uses SA for diffusion. It is quite sharp wide open - a little sharper than a Heliar but not as sharp as an Eidoscope.

2. My 48cm Nicola Perscheid is a triplet. It has noticeable residual CA and more SA than the 42cm. The combined effect is like a Gundlach Equal Diffusion, and that's a pretty foggy lens. Its sharpness wide open is less than that of a Heliar. So this lens has a pretty steep learning curve - at least for me.

3. Both lenses have the same German patent number engraved on the front rim, DRP 372059 which basically described how residual aberration can be used as diffusion but did not specify any particular optical layout.

4. The 42cm has a lower serial number than the 48cm. Both lenses are made to the same quality and finish and has the same barrel diameter and flange threads (both size and pitch).

These lenses are about 6 lbs each so it is very challenging to put them on a field camera. They were built to be used inside a studio on a huge camera. My Deardorff P8 can handle it without any issues but I am too nervous to bring them outside in case the Black Beast decides to call it quits at some point. Absolutely no chance on a V8.

Carver

[carverlux]

Interesting triplet. Is it possible that the center element is negative and simply used to increase the focal length of the basic doublet without appreciably changing the dimensions of the housing? Something like the early Dallmeyer Triple Achromat. Such a negative element might still preserve the soft aspect of the lens and not appreciably improve the degree of spherical correction.

Nate Potter, Austin TX.

Nate,

The diameters of both outer elements between my 42cm and 48cm are not the same. The 42cm is slightly smaller. The 42cm also appears to me as a cemented doublet but the 48cm triplet is truly an uncemented triplet, not a cemented triplet as in a Heliar.

Carver