FlyPenFly wrote:
As far as sharpness, it seems the Contax G may have a floating element? Because sharpness is remarkably high even with macro distances.
The idea behind a floating element is that it allows a relative movement of one lens element (or a group) in relation to the rest of the lenses in order to correct for aberrations at close focussing distance. If you think about that for a second, the whole "floating action" would be lost by putting the optics in a helicoid and moving the whole thing in one piece in order to focus.
By the way, did you ever share some pics and details of that conversion? In case you did, I missed it and I'd be grateful if you could point me to the thread/post about it.
dcjs wrote:
The idea behind a floating element is that it allows a relative movement of one lens element (or a group) in relation to the rest of the lenses in order to correct for aberrations at close focussing distance. If you think about that for a second, the whole "floating action" would be lost by putting the optics in a helicoid and moving the whole thing in one piece in order to focus.
By the way, did you ever share some pics and details of that conversion? In case you did, I missed it and I'd be grateful if you could point me to the thread/post about it. ...Show more →
m-a-x posted a description a while back after he did the conversion. i can't find it now.
and yeah, the g 45 most definitely does not have a floating element and if it did it would be much more difficult to put in the helicoid of another lens, which i also recently did:
dcjs wrote:
The idea behind a floating element is that it allows a relative movement of one lens element (or a group) in relation to the rest of the lenses in order to correct for aberrations at close focussing distance. If you think about that for a second, the whole "floating action" would be lost by putting the optics in a helicoid and moving the whole thing in one piece in order to focus.
By the way, did you ever share some pics and details of that conversion? In case you did, I missed it and I'd be grateful if you could point me to the thread/post about it. ...Show more →
Couldn't you put a single element in separate gearing?
FlyPenFly wrote:
Couldn't you put a single element in separate gearing?
you could, but it would be seriously tough. you'd either have to take the helicoid(s) from a lens with identical design, make the helicoid yourself, or use two helicoids and have a lens with 2 focus rings that you move separately to achieve optimal sharpness.
i fully disassembled the lens, all elements move in a single block.
Yes, it is a single lens block. The G45 is so good without a floating design.
Here's the link to the description, dcjs: https://www.fredmiranda.com/forum/topic/1085131/0
I will do it again and intend to better document the process with pictures, but due to a lack of time it will be winter before I publish it.
Phillip - your Wales shots are gorgeous.
Uhoh7 - last two landscapes are excellent.
Sebboh - that Rokkor shot is great.
FlyPenFly - amazing detail and color in those watches.
Freak - love the "Little Prince" shot.
Thanks Bill!
The Planar shot is perhaps a bit over sharpened, due to the high texture.
The Sonnar shot I like myself a lot.
Off camera flash was used from an angle in both shots, hand-triggered during long exposures.
mortyb wrote:
Phillip Reeve (or anyone), do you use cornerfix or similar on your CV 15/4.5 shots?
I've used this lens with my Nex-5n (with Voigtländer adapter) for a week, and it has some serious vignetting and some color shift as well. Infinity is worse than close-up. Aperture doesn't seem to matter that much. I mostly shot at infinity at f8. I'm considering sending it back because of the vignetting.
I have the same issue with my CV15/5N combo. I thought it might be the adapter (Rainbow Imaging), but apparently not.
CornerFix works well once you get a good lens profile. It is a couple of extra steps to convet to DNG and then run through CornerFix, but the results are worth it IMO.
Before/after CornerFix:
http://bimjo.com/examples/cornerfix_n.jpg
http://bimjo.com/examples/cornerfix_2.jpg
CS/LR adjustments from the corrected file as you normally would process a RAW file. This one wasn't processed beyond the CF adjustments.
