Ambro51 Posted December 10, 2018 Share #21 Posted December 10, 2018 Advertisement (gone after registration) Well not modified, but “scratch built”. I made three of these a few years ago, two were sold and I have kept this one. Welcome, dear visitor! As registered member you'd see an image here… Simply register for free here – We are always happy to welcome new members! 1 Quote Link to post Share on other sites Simply register for free here – We are always happy to welcome new members! ' data-webShareUrl='https://www.l-camera-forum.com/topic/292088-leitz-epis-1000mm-f35-lens-20x24-inch-lf-camera/?do=findComment&comment=3645028'>More sharing options...
Advertisement Posted December 10, 2018 Posted December 10, 2018 Hi Ambro51, Take a look here Leitz EPIS 1000mm f3.5 lens 20x24 inch LF camera. I'm sure you'll find what you were looking for!
Ambro51 Posted December 10, 2018 Share #22 Posted December 10, 2018 Front. .... oh and yes it works Welcome, dear visitor! As registered member you'd see an image here… Simply register for free here – We are always happy to welcome new members! 1 Quote Link to post Share on other sites Simply register for free here – We are always happy to welcome new members! ' data-webShareUrl='https://www.l-camera-forum.com/topic/292088-leitz-epis-1000mm-f35-lens-20x24-inch-lf-camera/?do=findComment&comment=3645031'>More sharing options...
dkCambridgeshire Posted December 10, 2018 Author Share #23 Posted December 10, 2018 ^^^ Ahhh! Maybe you posted something on the forum a few years ago ? I tried to find the original post but without success. Thank you dunk Quote Link to post Share on other sites More sharing options...
dkCambridgeshire Posted December 10, 2018 Author Share #24 Posted December 10, 2018 On 12/8/2018 at 1:45 PM, Ambro51 said: A superb lens for him to use IF he wants absolutely perfect “landscape” images,, in focus corner to corner, is a single achromat. With the recent influx of Chinese refractors, these lenses are plentiful. I’d suggest a 3” or 4” diameter lens from F 12 to F 15. A washer stop is needed in front of the lens, placed one lens diameter in front, with an opening 1/3 of the lens diameter. The lens is ‘reversed’, so the convex side faces the plate. While the aperature is small, exposures for positives will be about 30-60 seconds. •••••• this lens will give “Ansel Adams” type of clarity and focus.......and Yes with 25 years doing Wet Plate and building cameras, I know what I’m talking about. Could you possibly please post an image made using an achromat with a single front mounted 'washer' stop' ? dunk Quote Link to post Share on other sites More sharing options...
Ambro51 Posted December 10, 2018 Share #25 Posted December 10, 2018 (edited) Yes. Probably under “Wet Plate Leica”. I hardly use it, but from tests it functions like any wet plate camera. Outdoors, by the cap, 4 seconds at F 8 gave a nice image on black glass. On clear glass a bit longer exposure would give a printable negative. By the grainless collodion process the print will be higher quality than a silver gelatin negative. Edited December 10, 2018 by Ambro51 1 Quote Link to post Share on other sites More sharing options...
Ambro51 Posted December 10, 2018 Share #26 Posted December 10, 2018 I probably have a few old civil war re-enactment group shots. They were done using a common practice of the day (and what I’m suggesting re. Prior posts) of using the single front achromat of the petzval lens reversed and installed in place of the removed rear element. A stop was inserted, focal length much longer and pin sharpness. 1 Quote Link to post Share on other sites More sharing options...
dkCambridgeshire Posted December 10, 2018 Author Share #27 Posted December 10, 2018 Advertisement (gone after registration) ^^^ Very interesting … Thank you dunk Quote Link to post Share on other sites More sharing options...
pgk Posted December 10, 2018 Share #28 Posted December 10, 2018 14 minutes ago, dkCambridgeshire said: Could you possibly please post an image made using an achromat with a single front mounted 'washer' stop' ? dunk Hi Dunk I should be able to do this before long too (just building a front panel/shutter to use an 1850s lens). From my reading the position of the front stop is a compromise because its placement changes aberrations, and the position is a trade off of increasing one at the same time as decreasing another. I think that Kingslake mentions this but I can't find the section at the moment - I'll have another look later. 1 Quote Link to post Share on other sites More sharing options...
dkCambridgeshire Posted December 10, 2018 Author Share #29 Posted December 10, 2018 ^^^ Very interesting Paul … Thank you. dunk Quote Link to post Share on other sites More sharing options...
dkCambridgeshire Posted December 10, 2018 Author Share #30 Posted December 10, 2018 (edited) Paul, There are three Kingslake books . Can you please advise which one you refer to? Optics in photographyRudolf Kingslake booksOptical System Design A history of the photographic lens Rudolf Kingslake Lens design fundamentals Rudolf Kingslake Optical System Design Rudolf Kingslake Thank you dunk Edited December 10, 2018 by dkCambridgeshire Quote Link to post Share on other sites More sharing options...
willeica Posted December 10, 2018 Share #31 Posted December 10, 2018 Dunk. I will send you an extract from the Lens Vademecum which covers, inter alia, the Grubb lenses which are mainly Aplanatic rather than achromatic. It does, however, go into some detail about the variable effects when using central washer stops. Both of my Grubb lenses have holders for such stops. If you feel it is worthwhile, feel free to pass it on to Tony and give him my best regards. The Grubb Section starts at about page 66 out of 74 of what I am sending to you. William Quote Link to post Share on other sites More sharing options...
dkCambridgeshire Posted December 10, 2018 Author Share #32 Posted December 10, 2018 2 hours ago, willeica said: Dunk. I will send you an extract from the Lens Vademecum which covers, inter alia, the Grubb lenses which are mainly Aplanatic rather than achromatic. It does, however, go into some detail about the variable effects when using central washer stops. Both of my Grubb lenses have holders for such stops. If you feel it is worthwhile, feel free to pass it on to Tony and give him my best regards. The Grubb Section starts at about page 66 out of 74 of what I am sending to you. William Thank you very much William … a wealth of information and have passed on to Tony … and will also study myself. Regards dunk Quote Link to post Share on other sites More sharing options...
pgk Posted December 10, 2018 Share #33 Posted December 10, 2018 Sorry - A history of the photographic lens - I'll try to find the page and post. 1 Quote Link to post Share on other sites More sharing options...
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