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Comment by davidwozhere posted on Yesterday's walk near Cadover Bridge. at 01/11/2024 - 00:35
Bloody 'ell, they are flippin' good!
Comment by davidwozhere posted on Re-done Astro at 01/11/2024 - 00:30
Comment by davidwozhere posted on Latest Meyer Optik Trioplan conversion. at 27/10/2024 - 10:09
Comment by davidwozhere posted on Spad's Astro Part Alpha at 27/10/2024 - 00:49
Comment by davidwozhere posted on Spad's Astro Part Deux at 27/10/2024 - 00:47
Comment by davidwozhere posted on Spad's Astro Part Tre - The Comet at 27/10/2024 - 00:46



This link will provide a year of manufacture calculator for many vintage lenses based on their serial number.
It says mine was made in 1934.
Comment by davidwozhere posted on Latest Meyer Optik Trioplan conversion. at 25/10/2024 - 23:53
These cameras consist of three distinct parts:
A light tight metal or wooden box with provision for either glass plates, sheet film or roll film transport.
A shutter to control the light admitted into the metal box with aperture and exposure controls.
And a lens in front of the shutter. Most of these enable the front element to be screwed outwards or inwards in order to focus.
Now throw everything away except for the shutter and the lens. I described a while back how this whole unit can be fitted with an M42 thread. That is then attached (by trial and error) to the right length of extension tube to enable infinity focus with the shortest extension possible. You can then make final focus by screwing the front element in and out, as originally intended.
Now swap one of the extension pieces with a focusing helicoid. The original designers never envisioned this trick! It enables you to screw the front element all (or part) the way out, as if it were a modestly magnifying macro lens which will bring very close subjects into focus at (say) two or three feet with a 105mm lens. The helicoid is used to refine that focus while the background doesn't have a hope of being anywhere near focus. The result is mega bubble bokeh if there are sufficient bright objects in the background to produce the out of focus bubbles. What you are actually doing by screwing the front element in and out is changing the focal length of the entire assembly! That is then focused by using the helicoid.
The 'bubbles' are produced due to the near circular aperture of a multi-bladed Meyer Optik iris. Fully open you get big bubbles which reduce in size as you stop down until you reach a point where the image appears more 'conventional'. In short, you can use one of these converted lens-shutter-helicoid assemblies over the entire range from high quality conventional photography to near macro with or without 'Trioplan bubbles', as you choose.
I finally got this one calibrated with its extension tubes this afternoon and I took it into the garden on the end of a K1. This image is the very first shot I took with it. The withered purple toadflax in the foreground is about 3 feet away. The front element has been screwed right out to achieve this. The background is a mixture of green leaves and the autumn colours of an acer tree caught in the sunshine. Had there not been a focusing helicoid I would have had to use the front element alone to focus which would have meant me stepping back about 6 to 8 feet and so bringing both foreground and background together, thus producing a 'nice' conventional shot,
I hope that lot makes sense - here is the result ....

Comment by davidwozhere posted on Latest Meyer Optik Trioplan conversion. at 25/10/2024 - 00:11
Comment by davidwozhere posted on The colours of RHS Harlow Carr (1) at 24/10/2024 - 00:46
Comment by davidwozhere posted on Can you guess what this is 2 at 24/10/2024 - 00:44

