Any info on Emil Busch Rapid-Aplanat f:7 F=20cm?

[Peter Yeti]

I just picked up an Emil Busch Rapid-Aplanat f:7 F=20cm in beautiful condition, got it for a song. Now I'm wondering if there is any information on this lens because I'm a little puzzled (plus I'm not an expert on these old lenses). The barrel seems to be brass but the lenses are mounted in aluminum plus the whole lens is painted black. My feeling is that this must be a pretty late model, perhaps from the 1920s. I thought that rapid aplanats (or rapid rectilinears) were pretty outdated by then.

Does anyone of you experts have an idea when this was made? Was this possibly intended as portrait lens? I'm curious about it's characteristics but I still need to mount it on a lens board before I can test it. Can't wait...

Anyway, here are two pictures showing my new beauty:

[E. von Hoegh]

I don't have a list of Bush serial numbers, but RR/Aplanats were made into the teens and twenties by several firms. They were for general use, and are usually quite good.
That lens looks pristine... try it on 4x5, I bet you'll like it.

[Steven Tribe]

I assume this must be the late (after 1927) version of the series D rapid aplanat, when the series idea had been given up.
This is about the commonest 5x7" aplanat ever made, although this is a late one.

Brass/aluminium combinations are quite common.

This is nothing "inadequate" about aplanats/RR - but they couldn't compete with F4.5 anastigmats.
Date should be findable using google or the Lens VM.

[Peter Yeti]

Thanks a lot for you help. Unfortunately, I don't have the Lens VM since I'm not a collector. I also couldn't find anything about the serial numbers on the web. The series D seems to have f:8 rather than f:7. I read that Emil Busch A.-G. was taken over by Zeiss in 1927 and stopped making lenses after this takeover. Could this be right? They must have been one of the oldest of all German lens makers and are said to have had a very good reputation. The condition is very good, though not pristine. There is a tiny scratch on the rear element, which should have no visible effect on image quality (I hope).

So, I still hope that someone has more information. Seems that the knowledge about Busch lenses is much less than about Zeiss, Goerz, and Meyer.

[Steven Tribe]

Yes the series D was an F8.
Busch also has a F6 - F7 Detective aplanat (only in smaller series - up to 18cm) - so this one could have been a development of this.
Busch were still making the Nicola Perscheid as late as 1935 and lens VM says they continued until the end of WWII.