50mm 1.8 + .5x wide angle converter?

[Matthew P]

I was just wondering how a wide angle converter would affect a lens... My 50mm should become a 25mm (50mm on gh1) lens, but what about the aperture? Will adding a wide angle converter simply make it into a 25mm 1.8, or is there more to it than that? Is the aperture relative to focal length? Will it really be a 25mm 3.6?

 

[roei z]

nice idea, but wouldn't it also lower the quality of the overall picture ?

 

[nosys70]

more glass, less light, so you should loose usually at least one stop.
wide angle convereter are known to add a "haze" over the picture (less contrast) and at worse , heavy CA on the side.
you better will spend some money on a real 30mm lens like the sigma

 

[Matthew P]

I've already got the converter though, as I used it on a HF00. All I'd need is to buy a step down ring... and that's not going to cost much. Besides, I got this 50mm for free (it had a tiny patch of fungus on it; but I disassembled the lens and cleaned it off completely), so I'm not going to complain about a bit of CA or haze, if there is any... Although, the adapter I've got is actually pretty good, and does not really suffer from 'haze', nor any light loss (at all). It does get some CA on the sides when converting to say, 24mm equiv, but this is going to go on a 50mm lens (which would be 100mm on the gh1). So with the GH1's crop, it's very unlikely that CA would be very noticeable. I plan on finding out though!

I've attached an image taken from the HF100's video with the converter on. I've zoomed it in to the equivalent focal length of 50mm, so the GH1 with the 50mm and converter should look similar but with that lovely shallow DoF.



Anyway, my original question on the aperture still stands. Have I got a 25mm 1.8 lens for the cost of a step down ring, or is there more to apertures than that?

 

[mojo43]

There was a bunch of threads about this way back. Do a search on the forums... There is virtually no light loss, but the quality really depends on the adapter. I believe that there was one thread where a guy was using the wide angle adapter with the 20mm and it worked well....