paulmoore Posted June 24, 2009 Share #21 Posted June 24, 2009 Advertisement (gone after registration) A 1.25x extender could expand the image circle to fill the S2's sensor. That's how I came up with the 1.25x figure. And an electro-mechanical interface in the extender could maintain full-aperture metering and auto-diaphragm. I wouldn't worry too much about a loss of resolution from the extender. My 280 f/4 with the old 1.4x APO-Extender out-resolves the DMR's sensor. I'd expect a new extender of lesser magnification could do as well even if it's providing a bigger image circle. Look what Leica has to gain with this sort of thing: The S2 would have immediate access to stuff like the modular APO-Telyts instead of just the few CS lenses initially planned. I'd think the S2 body would be an easier sell with a broader range of lenses. I agree doug..not sure who could argue any points here unless they just want to be neighsayers. regarding dof of lenses.... the depth of field of my 50lux does not change regardless of what body it is mounted to.. I can understand if there is a percieved difference of critical focus due to the resolving power of the sensor..again all I was trying to get across is if I like the look of my 50lux on dmr.. I would like it on an S2 as described by doug. I get the physics of what happens when extenders are used or switching from large to small sensors..If using the extender would help get this on the drawing table I would not mind the increase of focal length but would not like to loose more than 2/3 of a stop.. stop down metering would not be welcome either.. Link to post Share on other sites More sharing options...
Advertisement Posted June 24, 2009 Posted June 24, 2009 Hi paulmoore, Take a look here maybe I'm daft but.... I'm sure you'll find what you were looking for!
wildlightphoto Posted June 24, 2009 Author Share #22 Posted June 24, 2009 ... would not like to loose more than 2/3 of a stop.. stop down metering would not be welcome either.. As I figure it the 1.25x extender would lose about 2/3 of a stop. Regarding the gunstock shooter in Alan's post... I use an old (ca. 1968) Leica shoulder stock along with a monopod. The shoulder stock attaches to the lens' rotating tripod collar so vertical photos are no problem. I've been using it for a little over 7 years. Link to post Share on other sites More sharing options...
ALUX Posted June 24, 2009 Share #23 Posted June 24, 2009 Just some brainstorming while recovering from endorphin deprivation ... suppose Leica were to make a 1.25x Apo-Extender-R/S that would make R lenses usable on the S2 with the lens' original field of view? As I'm envisioning it the extender could have the electronics and mechanical couplings to meter at full aperture and stop down the diaphragm, controlled by the body. Would this interest anyone? Why not going the other way and offering a 0.5x Extender (actually I should rather say compressor)? A conventional 2x-extender blows up the image projected by the lens by a factor (linearly) of two. The image area is four times larger which means that you loose 2 f-stops. If you think the other way around, a 0.5x converter would shrink the image by a factor of two. That means the light is now concentrated on 1/4 of the original sensor area and you gain two f-stops! For instance a Summilux 1.4/50mm would become a 0.7/25mm. Thus, R-lenses could be used on FT-bodies according to their initial purpose: A wide angle lens stays wide and a tele stays a tele! And that is not all: While a 2x-extender blows up all the abberations and other optical errors of the original optic and thus degrades image quality. However, a 0.5x converter should theoretically not blow up optical errors, as long as it does not introduce own errors. Thus, a well constructed 0.5x converter should have virtually no impact on the image quality. In addition to all I wrote above, such an converter would help to generate space between the lens and the FT body. One could use this space to incoproate a device that closes the aperture upon shutter release, is triggered by a signal from the body! The overall result would be a fully FT compatible R lens! Maybe I am completely mistaken, but from a logical point of view that sounds reasonable to me What do you think? Best regards, Alex Link to post Share on other sites More sharing options...
leicanut2 Posted June 26, 2009 Share #24 Posted June 26, 2009 I like Dougs idea and Alex's but may have to sell off stuff and get out of retirement to buy a S camera body. Jan Link to post Share on other sites More sharing options...
Riley Posted June 26, 2009 Share #25 Posted June 26, 2009 Why not going the other way and offering a 0.5x Extender (actually I should rather say compressor)? A conventional 2x-extender blows up the image projected by the lens by a factor (linearly) of two. The image area is four times larger which means that you loose 2 f-stops.If you think the other way around, a 0.5x converter would shrink the image by a factor of two. That means the light is now concentrated on 1/4 of the original sensor area and you gain two f-stops! For instance a Summilux 1.4/50mm would become a 0.7/25mm. Thus, R-lenses could be used on FT-bodies according to their initial purpose: A wide angle lens stays wide and a tele stays a tele! And that is not all: While a 2x-extender blows up all the abberations and other optical errors of the original optic and thus degrades image quality. However, a 0.5x converter should theoretically not blow up optical errors, as long as it does not introduce own errors. Thus, a well constructed 0.5x converter should have virtually no impact on the image quality. In addition to all I wrote above, such an converter would help to generate space between the lens and the FT body. One could use this space to incoproate a device that closes the aperture upon shutter release, is triggered by a signal from the body! The overall result would be a fully FT compatible R lens! Maybe I am completely mistaken, but from a logical point of view that sounds reasonable to me What do you think? Best regards, Alex the name you seek is a focal reducer, and indeed it has been done The Olympus 14-35/2 and 35-100/2 are generated from a 28-70/2.8 and a 70-200/2.8, while they have inbuilt a 2x focal reducer, they are throttled down one stop. In effect the FL changes via 2x, but the F stop only by a stop. As proof, you can fit the lens to an E body, and if you press the lens release button, the lens will still meter (still being electrically connected) and find the lens opens up around 2/3 stop. this is the 35-100/2 on an E3 body, the focal reducer can be seen on the rear Link to post Share on other sites More sharing options...
Recommended Posts
Archived
This topic is now archived and is closed to further replies.