Responding to an earlier post in this thread re Watkins use of a Grubb C in Yosemite in 1861 - it seems that to cover 18x22 a focal length close to 30 inches would be necessary. Could any Grubb cover the mammoth plate format? Im doing research for a book on Watkins and find information on his tools difficult to find.
The Grubb Patent Aplanat with the code C had a 3" diameter lens, a 'true focus" of 15" and was advertised as covering from 10” x 8” to 12” x 10”, which could be varied by moving the washer stop holding mechanism in or out. Back in ~1860 the cost of the lens was £5 0s. 0d. Thomas Grubb did argue in the British Photographic Press with Sutton (who invented the Sotton Panoramic Lens) about lens coverage, and Grubb maintained that lens coverage should be defined as actual, usable coverage rather than the overall circle which was illuminated (actually he and Sutton were very antagonistic towards each other in the press generally over technical optical matters, as were many others with Sutton). Thomas Grubb probably ensured that the C lens could only physically operate from 10” x 8” to 12” x 10” in its mount. Mine certainly covers 10" x 8" and by using front shift it will cover more but my camera won't really let me do tests much beyond the 12" x 10" even shifting the front. My guess is that Thomas was right though and that 12" x 10" was the lenses limit for decent 'quality' images. I would be really very interested to know if you are able to determine and photographs by Watkins which were taken on the Grubb C lens. I've tracked down one or two taken by Bedford and Bourne which are confirmed as having been shot on Grubb Cs, but only one by Watkins which appears was probably/possibly taken on his Grubb C.
The only other comment I would make is that the Grubb F lens was advertised as having coverage from 18” x 16” to 22” x 20” and the G lens 22” x 20” to 26” x 22” so these would come closest to fitting your 18" x 22" coverage. I have not been able to track any examples of either as having survived, and at £14 and £20 they would have been very expensive. I do just wonder if it would be easy to mistake a written G for a C ..... ?
If you need any further information please pm me.
I agree with everything that Paul (pgk) has said. An F or a G Grubb lens would have given the coverage necessary with focal lengths of 25" and 30 " respectively. The books about Watkins refer to a C lens as having been used, but you may need to go back to source documents to establish the basis for that. It is possible that a G was mistaken for a C. The table to which Paul refers can be seen on Post 80 here or in my article here http://britishphotohistory.ning.com/...ommon-practice . I have seen calotype negatives taken in Ireland by Thomas Grubb himself from the early 1850s which were 10x8, implying a lens size of around that of the C. I have also seen some smaller prints by Grubb of around 7x5 or 8x6, which were displayed in an exhibition in 1857 and which may have been taken by a lens of around the A size. My biggest Grubb lens is a D, but that would not produce 18x22. The other issue is the size of the camera used by Watkins and the extension that was possible.
William
This is an amazing thread - an amazing forum.
Another possibility referenced here.
https://archive.rps.org/archive/volu...=Grubb%20globe
There is an early letter somewhere where Watkins mentions a "globe" lens
The 1861 images ( I have seen original prints -Bancroft Library) are distinctly soft near the edges. The later new series from the 70s are very sharp into the corners. Watkins was a perfectionist. Whatever he used in 1861 was upgraded later. Bit that is another story.
Jerry
The dates of the Globe lens would need delving into: https://antiquecameras.net/harrisonglobelens.html and the date of the letter looking at.Originally Posted by gfranzen
I have no doubt at all that Grubb was producing his Patent lenses in 1857 and possibly (as pre-patented lenses) slightly earlier They were certainly in use by 1857/8 by photographers as is evidenced in the photographic press of the time.
Whilst researching Grubb, William (Willeica) and I have found a lot of evidence for dates which has then proven to be completely wrng when hard evidence has turned up! Its a difficult area of research. So for example, Kingslake wondered whether Dallmeyer came up with the Raid Rectilinear by combining two Grubb Patent Aplanatic lenses. In fact Grubb hade made and supplied such a lens two years before Dallmeyer patented it. But it wasn't until we saw a copy of a ledger confirming manufacture date that we could show that this had happened. Tracking down such material is hit and miss and very difficult.
As regards what Watkins had, Tyler Green in 'Making the West American' mentions a 'cutting edge' Grubb C lens. I do, however, remember some mention of a Globe lens in connection with Watkins, but I cannot recall where.
The RPS link is interesting in that it refers to an image of Trinity College, which may be one that I have seen in a print. There is minor central barrel distortion in this image which may have been taken in the early 1850s. It is an image of about 7x5 or 8x6 and it is printed on flimsy but glossy paper and had been folded into a quarter size. It may well be the print of Trinity College which was entered into the 1857 London Society Exhibition at around the time that he made his patent application. It does , however, contain the distinctive handwriting of Thomas Grubb on the back, where he had written 'Note the railings in front of the College are in a curve' . The edges in the image, which may date from the early 1850s, are sharp and there is no sign of corner softness. As I indicated above, I believe that this image may have been taken with an A size lens. The notation on the back includes 'indecipherable' 70 degrees and 'College' 60 degrees.
I have a photograph of this print taken with a smartphone, but I cannot share it on a public forum as the print is still in private hands.
William
Isn't the list on #52 updated anymore? Samples of the Grubb lenses in later posts like the ones from Williams' collection are not in the list - at least not all....
I will get around to it befor too long Ron. Just a few more records of existant lenses to add in.
This was written by a member from another photo forum which might be of interest:
"In a book I have it is said he possibly used a Grubb-C in his early 1860's work but had to cut off the corners due to the lack of coverage for his mammoth plates and dicarded it for a wide-angled lens which he used for the 1865-66 Yosemite Survey pictures. They began to show much more space in the photos and he ceased cutting the corners of the photos after the purchase of the wide lens.....From a great book I bought at the Amon Carter Museum in Ft.Worth called CARLETON WATKINS--THE ART OF PERCEPTION"
<edit> perhaps the above was already known to some fellow members, since I just encountered this thread:https://www.largeformatphotography.i...h-plate-camera
Last edited by Ron (Netherlands); 29-Oct-2022 at 15:18.
Another one for the list to add? has a clear serial number (perhaps bought by one of our fellowmembers):
https://www.ebay.co.uk/itm/Thomas-Gr...p2047675.l2557
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