2 more surfaced.
770 and 2175 . Both aplanatics - can be found in Germany - enough said! Both a bit out of the ordinary.
2 more surfaced.
770 and 2175 . Both aplanatics - can be found in Germany - enough said! Both a bit out of the ordinary.
A couple of unusual Grubb lenses at auction.
770 looks like an Aplanatic, but is said to be achromatic portrait f5.5, obviously added much later as f stops, as we know them, did not exist in the 1850s/60s.
2175 is said to be an Aplanatic, but has an unusual conical structure and comes with two washer stops. No obvious engraving.
William
Last edited by Willeica; 14-Mar-2020 at 05:03.
Both look modified to me. It would be essential to check that both have the serial number micro-engraved on the lens glass in order to determine just how unoriginal either actually is.
Edit. Having looked carefully at the photos my guess is that 770 was modified well after it was manufactured because the roughly engraved 'Portrait f 5.5' suggests the engraver was used to f numbers which is suggests this engraving was made in 1870s or very probably later. The aperture stops appear to be large and fitted below the position of the original but I'm not sure of the effect of doing this - softening the image perhaps?. 2175 looks like an 'A' series stereo lens (and its physical size/focal length is close to those ascribed in adverts to the 'A' Stereo Grubb too) in an odd and decidedly unoriginal mount. I just wonder if at some point it was modified and repurposed with other old lens parts so that it could be used in an enlarger? If so its dark brown colour may be as a result of exposure to darkroom chemical fumes?
Last edited by pgk; 14-Mar-2020 at 14:49.
I agree with Paul's (pgk) assessment of the 770 and 2175 lenses. Paul has better eyesight than I have and there is, indeed, some engraving on 770. It has a very dark colour like my 482, which I showed earlier and which might have been the result of having spent a lot of time in the workshop or lab. I suspect that 482 might have been used by the Grubbs in their workshop, hence the stamping rather than the engraving. There have been a few Grubb lenses appearing recently which have had mount or barrel alterations. As I know from my own experiments, the optical quality of the lenses is superb and, therefore, the existence of altered mounts and barrels and other features for different cameras and work types is hardly surprising.
William
I have now acquired Grubb Aplanatic C lens 4039.
This means I now have the earliest and the latest, currently known, Aplanatic C lenses - 482 (unmarked but the same size lens) and 4039. There are, perhaps, earlier and later lenses out there. The lens from 482 screws into the body of 4039, but the reverse does not apply. The flange from 4039 does not fit on 482, but the washer stop, made for me by pgk, fits on both lenses, albeit it is slightly loose on 482. The body of 482, which is probably pre-main production, is slightly taller than that of 4039. I will publish a full 'class photo' of my 5 Grubb Aplanatics when I get one done.
William
Yes. Although not marked as such (it probably pre-dated the code letters) it looks very much like it was probably what would later be coded as a B2 Petzval by Grubb - quite a popular lens I think.
Here is my latest Grubb item a C Type Aplanatic No 582 with plain engraving or stamping. It does have the engraved 'Grubb Patent No 582' as proof of authenticity on the rim of the glass (poor photo attached). Some data about f stop calculation is written inside inside the top cap, but this would have been added much later. A class photo of my Grubb lens collection is also shown below.
William
Grubb 'C' Patent Lenses has a 3" diameter glass. 'A' was 2" and they went up to 'G' (6"). There were smaller lenses for stereo use, Doublets (see below) and Petzvals. Later Grubb's were by Howard, Thomas's son and varied with many being Doublets. Still working on a history of Grubb lenses but its looking as though Thomas Grubb was the first maker to produce the Doublets which would become better known as Rapid Rectilinear lenses, in 1864 ..... tbc
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