MS Optical Sonnetar 50 Focus Shift Compensation

tuanvinh2000

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Nov 15, 2010
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Hi there,
I think there might be some users of this lens that have developed a focus shift compensation method when use this at f1.1 or f1.4. I did some basic measurements myself to always tune it a bit closer to me from the focus point (0.01 meter) wide open. Want to hear others using this lens with rangefinders and how to get best results from it. Do you even compensate for focus shift at all?
 
Are you using it on a film or digital body (or both)? Since I use both, I found it pretty easy to use a digital body to experiment w/the coma adjustment ring. I have mine set a touch closer than the 4m default setting (more like 3.8 or 3.9m) so that it's mostly in focus (hit rate is obviously higher for film) wide-open (or nearly so) at the shooting distances I favor (5m & closer). Disclaimer: I rarely use the Sonnetar stopped down further than f/2; for me, it's more trouble than it's worth to use it as a general purpose 50.
 
i use mainly on film bodies. I have a live view gxr for the digital but that doesn't need any adjustment since it's live view.
got it quite dead one from f2 and more close down. but f1.4 the focus point seems to be a bit closer than my RF focuses at, i usually at 1-3 meters distance and the closer the further they are. dont have a digital rf to measure the exact difference i should compensate for. may i ask what's your success rate with close distance and with f1.1 -> f1.4 and no compensation. it's fairly new to me and i dont get correct focus on film yet.
 
Sorry, I meant digital RF body.

I don't know about percentage, but as I wrote, setting the coma adjustment ring for < 4m, but > 2m did the trick for me, but that's for shooting wide open all the time & I'd rather adjust the Sonnetar than alter my shooting technique for just 1 lens. As a handmade lens, it would not surprise me if there's significant sample variation, so I would experiment w/several rolls (or borrow someone's M9/ME or 240) at different apertures & different coma settings. If you shoot mostly at f/2, it sounds like you have it dialed in & it might be easier to just lean in when shooting wider, but it's a personal choice & you can't have it both ways w/focus shift.

i use mainly on film bodies. I have a live view gxr for the digital but that doesn't need any adjustment since it's live view.
got it quite dead one from f2 and more close down. but f1.4 the focus point seems to be a bit closer than my RF focuses at, i usually at 1-3 meters distance and the closer the further they are. dont have a digital rf to measure the exact difference i should compensate for. may i ask what's your success rate with close distance and with f1.1 -> f1.4 and no compensation. it's fairly new to me and i dont get correct focus on film yet.
 
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