remik Posted October 1, 2012 Share #1 Posted October 1, 2012 Advertisement (gone after registration) Hi All, I hope this is the right place to post this question in the new forum... I've recently put together a Viso 1 system for my IIIf with a Bellows 1, Hektor 135mm and Elmar 90mm. I have the dual cable release. I have the short focus mount for the Hektor, and the bellows fittings for the lens head of the Elmar and the Hektor as well. I also played around a bit with my Summitar for a laugh. I shot a roll of HP5+ over the weekend testing out the various combinations in the backyard. Managed to create some nice moody shots, particularly with the Summitar. The Elmar also worked well. With the Hektor, I had major back-focus on the developed film with both the short-focus mount on the Viso, and also the with the lens-head on the bellows: even though I had lovely focus on the Viso focussing screen at the time I depressed the shutter. With the Elmar and Summitar shots, the film focus is the focus I saw on the Viso screen- so there seems to be no issue with the Viso-camera connection. Can anyone explain how you can get a significantly different focus points at the film plane compared with the Viso focussing screen with the Hektor lens only? First- I've attached some shots of the set-up, and shots taken with the Summitar, and Elmar... 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! 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/189140-more-viso-craziness/?do=findComment&comment=2129786'>More sharing options...
Advertisement Posted October 1, 2012 Posted October 1, 2012 Hi remik, Take a look here More Viso Craziness. I'm sure you'll find what you were looking for!
remik Posted October 1, 2012 Author Share #2 Posted October 1, 2012 And now 3 shots from the Hector, The first on the Viso with the short-focus mount, and the next two with the lens-head attached to the bellows. Note how all three are significantly back-focussed, rendering the subject in the foreground completely out of focus, even though the focus was set well on the Viso focussing screen. Would appreciate any tips/ ideas as to what might be responsible...I just can't get past the idea that the focus on the Viso screen should be the same as at the film plane- what am I missing? Thanks Remi 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! 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/189140-more-viso-craziness/?do=findComment&comment=2129797'>More sharing options...
giordano Posted October 1, 2012 Share #3 Posted October 1, 2012 If you attach the Hektor in short mount to the Visoflex, set the focusing scale to infinity, and look at distant objects in the finder (aperture wide open), are they sharp? From your description of what you've been getting with your close-ups, I'd expect the image in the finder to be unsharp - and to get worse as you move the focusing ring away from infinity. If that's the case, the Visoflex needs adjustment. But before you do so, take some photographs of distant objects (at f/4.5 and f/5.6) with the focusing ring set to infinity. If these are unsatisfactory the lens needs sorting out first. Also, photograph a street scene or something similar with Elmar and Hektor. A scene that will let you focus on an object 10-15m distant and see whether the image is correctly-, back-, or front-focused. If both lenses produce back-focused images, the problem is most likely with the Viso. The reason for using distant objects is to have a small depth of focus so as to highlight any errors in the Visoflex. Link to post Share on other sites More sharing options...
luigi bertolotti Posted October 2, 2012 Share #4 Posted October 2, 2012 I also think that you had to make some tests with a controlled and systematic approach : basically, the factors to be taken into account are : 1) Visoflex device CAN be out of adjustment : in this case you had to observe a difference in focus from Viso' screen to film plane with any lens. 2) But, at short distances, there is another factor that can enter: the focus shift of certain lenses when the lens is stopped down : this CAN alter the focus you observe on screen (lens wide open) and the focus you get on film plane (lens stopped down), even if the Viso, in itself, is correctly adjusted. The pics you posted, even the ones taken with Summitar/Elmar, are not the best to test the focus... they are subjects with depth... and is not easy to be sure, at such short distances, that what you DID focus on screen is THE SAME object that looks focused on film : better to make tests with flat objects or, better again, with a focus chart (easy to find on the Net, ready to print) properly used. This, to test the 50mm lenses and the correct adjustment of Viso, making some tests at different f stops AND different distances. For the 135, follow Giordano's advice, starting from test at infinity. (Of course, those test are a lot simpler to do with digital... ) Link to post Share on other sites More sharing options...
remik Posted October 2, 2012 Author Share #5 Posted October 2, 2012 Thanks for all of your tips, I had a look at my Viso mirror, and it seems to return to the appropriate position after being raised. Also, screwing in the cable release did not seem to alter mirror position. I checked focus on a fixed point with both pushing the mirror all the way back with my finger vs letting it fall back after using the cable release- no difference. What I did forget to mention is that my Visoflex is a micro-Viso version with interchangeable focussing screens. All my photos were taken with the clear focussing screen, rather than the ground glass. Which got me thinking... I set up a simple test on a wall 2 metres or so away, with the Hektor mounted on the Viso with the short-focussing mount. With the clear screen, focus was achieved with the mount reading 8.5 feet, when I did the same with the ground glass it read 7.5 feet. This may well be the solution and I will trial a few shots over the weekend when I have a chance. Will let you know. Remi Link to post Share on other sites More sharing options...
luigi bertolotti Posted October 2, 2012 Share #6 Posted October 2, 2012 Thanks for all of your tips,... What I did forget to mention is that my Visoflex is a micro-Viso version with interchangeable focussing screens..... Uh.. I didn't look with the right attention to the pic of your gear... ... it's clearly a Micro... Link to post Share on other sites More sharing options...
remik Posted October 4, 2012 Author Share #7 Posted October 4, 2012 Advertisement (gone after registration) So, I had a chance to put the Hektor on the camera and take a few shots, without any problems. Tried again with the Hektor on the Viso and Bellows, but this time using the ground glass rather than the clear glass in the micro-Viso for focussing...much better. Remi 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! 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/189140-more-viso-craziness/?do=findComment&comment=2133174'>More sharing options...
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