06-20-2012, 07:33 PM
[quote name='Frank' timestamp='1340159622' post='18976']
Thank you all for your kind responses. It seems the WA converter is pretty good. I also find some sample images at dpreview (but not 100% size), they look remarkably good: [url="http://forums.dpreview.com/forums/readflat.asp?forum=1041&thread=41477322&page=1"]http://forums.dprevi...41477322&page=1[/url]
From the information that I gathered, a WA converter does not change FL, does not change aperture, [color="#0000ff"]so it also does not change the DoF at the same focus distance[/color].
I think the DMW-GWC1 will be tested by PZ when new reviews on the X 14-42 and/or the 14/2.5 are published.
[/quote]
You're wrong there. It does change DoF, by the same factor that it actually dminishes the FL.It also changes the resulting FL. The only reason it doesn't change the aperture is because it uses the diaphragm and aperture placement of the original imaging lens.
Essentially, this works a bit like a static zoom lens, if you like. A zoom lens has an imaging group or groups of lenses, a group or groups of lenses which essentially determine the angle of view, and a group or groups of lenses which image the object onto the sensor. Essentially, a WA (or tele) converter which is front mounted is a new imaging plus static set of lens groups, where the lens this is fixed to behaves like the lens imaging the object as seen through the converter on the sensor.
This means that the imaging part of the convertor needs to deliver a (virtual) image large enough that it will not vignet when imaged by the lens it is attached to.
As to how well it works: it will never work as well as a decent prime lens of the resulting FL, not even with a specific, dediated attachment, for the simple reason that it is an afterthought and therefore not an optimal solution for a specific FL.
Kind regards, Wim
Thank you all for your kind responses. It seems the WA converter is pretty good. I also find some sample images at dpreview (but not 100% size), they look remarkably good: [url="http://forums.dpreview.com/forums/readflat.asp?forum=1041&thread=41477322&page=1"]http://forums.dprevi...41477322&page=1[/url]
From the information that I gathered, a WA converter does not change FL, does not change aperture, [color="#0000ff"]so it also does not change the DoF at the same focus distance[/color].
I think the DMW-GWC1 will be tested by PZ when new reviews on the X 14-42 and/or the 14/2.5 are published.
[/quote]
You're wrong there. It does change DoF, by the same factor that it actually dminishes the FL.It also changes the resulting FL. The only reason it doesn't change the aperture is because it uses the diaphragm and aperture placement of the original imaging lens.
Essentially, this works a bit like a static zoom lens, if you like. A zoom lens has an imaging group or groups of lenses, a group or groups of lenses which essentially determine the angle of view, and a group or groups of lenses which image the object onto the sensor. Essentially, a WA (or tele) converter which is front mounted is a new imaging plus static set of lens groups, where the lens this is fixed to behaves like the lens imaging the object as seen through the converter on the sensor.
This means that the imaging part of the convertor needs to deliver a (virtual) image large enough that it will not vignet when imaged by the lens it is attached to.
As to how well it works: it will never work as well as a decent prime lens of the resulting FL, not even with a specific, dediated attachment, for the simple reason that it is an afterthought and therefore not an optimal solution for a specific FL.
Kind regards, Wim
Gear: Canon EOS R with 3 primes and 2 zooms, 4 EF-R adapters, Canon EOS 5 (analog), 9 Canon EF primes, a lone Canon EF zoom, 2 extenders, 2 converters, tubes; Olympus OM-D 1 Mk II & Pen F with 12 primes, 6 zooms, and 3 Metabones EF-MFT adapters ....