Wide Angle - Raynox/Dome or Ikelite WA lens?

[howard4113]

Got a canon HG20 HD cam w/Ikelite case -- and I'm wondering which would give me wider angle of coverage: a Raynox HD-5050 conversion lens and Ikelite dome port -- or a Ikelite W-20 wet lens. I'm thinking the raynox because it's .5x - and the dome port keeps it at .5x. The W-20 is .56 but the face is flat thinking it's going to lose about 1/4 of that making it closer to a .7?
Q2 -- how about image quality?
Q3 -- what about vignetting?

Other thoughts?

Mark

 

[mobula]

Unfortunately, I don't know the Iklite W-20. I used the 5050 annd 3030 from Raynox on HC7, HC1 and HC3. Overwater the image quality of both lenses is not very good. In direction of the corneres they are losing visibly their sharpness. Underwater I didn't see this effect to much. I always prefered the 3030 because of the much bigger wideangle. Both are not fully zoomable, half is possible. So, why not the 0,3? Vignetting was not an issue, maybe a liitle bit.

 

[howard4113]

Well I got an Ikelite W20 and the angle of coverage is about the same as a 26mm lens on a 35mm camera. I'm basing this on the fact that it's just a bit wider than my nikon d300 18-200 lens at it's widest. The D300 has a 1.6 cropping factor compared to a standard to 35; so I'm figuring 16mm x 1.6=25.6mm. I use a 18-50 zoom on the D300 all the time underwater and it's OK - so I figure this will be OK too. Only variable is that my D300 has a dome port. The flat face of the W20 could kick it up to an equivalent 34mm -- less than optimal! The good news; no vignetting. This lens can be used as an aux but it weighs more that the camera itself!

Mark

 

[mobula]

;-) Honestly, I love filming and diving but I never got into the theorie of lenses and mm. I simply look at the results.

My stomach says: use the 0,5 from Raynox. I like the 0,3 much more, I had better results with it. But I never used it behind a dome port.