wide-angle lens question (Sony, Zunow, Schneider?)

[Alister Chapman]

Tom, first you say my statement about barrel distortion is wrong, then you go on to say that just about every wide angle adapter you have used has barrel distortion, so... as I say.... barrel distortion is the nature of the beast.

I'm not saying it's necessarily nice or pleasing, just that without spending enormous amounts of money barrel distortion is something you are going to have to live with especially with lenses designed to work with small imagers or film gates.

I'de place a good bet that the Bolex aspheron softens the image and introduces additional CA. It was never designed to work with the kinds of resolution that a camera like the EX1 can produce. I had a great 0.5x W/A adapter for my Z1 that had very little barrel distortion, but on the EX1 it is so soft it's unusable, especially at the mid to long end of the lens.

Sure I wish my Sony 0.8 was a bit wider, but for the money it is stunning value. In resolution terms I can't tell the difference between shots with it on and shots with it off. There is no noticeable vignetting, focus tracks perfectly and I have it on the camera most of the time.

[Tom Hardwick]

You're quite right Alister, any single element converter will soften the image and introduce additional CA, it's the law of the land. The less powerful it is the less CA, so that parallel sided glass filters hardly produce any.

I'd like to know the make and model of the 0.5x W/A adapter for your Z1 that had very little barrel distortion. It's presumably a zoom-through?

tom.

[Alister Chapman]

I wish I could remember the brand. It was Japanese and cost £750.00. It was an apochromat with a flourite element to reduce CA. I'll have to go back through my books and dig out the invoice. I bet a similar lens for the EX1 would be around the £1k mark.

[Tom Hardwick]

Sounds really interesting and the price seems ok vs the barrelling competition. Was there a reason you abandoned it (sold it?) other than it not being good enough for the EX1?

[Alister Chapman]

I sold the Z1 and it wasn't suitable for the EX so it went as part of the Z1 package. It was just a tiny bit soft on the Z1, but only at the mid to long end so I always removed it when I wasn't using it.

[Dean Sensui]

There are wide angle zoom lenses that exhibit almost no barrel distortion. I had a chance to try a Fujinon lens that was quite nice. It also cost more than $25,000 if I recall.

It's possible to eliminate the barrel distortion with After Effects. If I get a chance I'll post a still as an example.

[Charles Dasher]

I just noticed that Cavision is offering a series of lenses for the EX1 including a .4x fisheye. I have the SOny WA and the Schneider 1.6. but I am looking for a FishEye. I am not familiar with there lenses.
Any info is greatly appreciated.

Dasher

[Malcolm Hamilton]

Charles, thanks for bringing this up.
Here's a link, for those interested:

http://www.cavision.com/pictures/EX1/EX1.htm

Along with Charles, I'd love to know what people here think of this company. Even better... anyone tried one of these? (most interested in the zoom-through variety - - would that be the converter, rather than the adapter?)
Malcolm

P.S. how could I have made that link active?

[Malcolm Hamilton]

The Cavision .7x wide-angle converter (zoom-through) isn't out yet - - I've emailed the company to ask when it'll be released. Are there any other questions I should ask? On the web page that describes this lens, they mention that there is some vignetting at the perimeters. No barrel distortion is mentioned. Someone else could decipher this information better than I.
Cheers, Malcolm

[Tom Hardwick]

I bought a Cavision 0.5x zoom-through for my VX2k a few years back. I returned the first one as there were specks onside the lens that showed up quite clearly on footage.

The replacement had cleaner elements but vignetted the corners of the frame and barrel distorted badly. I swapped this out for a third but this was exactly the same, so I opted for my money back.

Nicely coated and sharp - so no quarrels there. Maybe QC is better these days - I hope so.

tom.

[Giroud Francois]

for my FX1 i use this :SCHNEIDER KREUZNACH Superwide Lens Aspheric IV
http://www.wittner-kinotechnik.de/ka...a/b_optike.php
and it is pretty good , absolutely no barrel.
the thread filter size is 77mm and i use un 77 to 72 ring adapter.
unfortunately mine is second hand and lens is acrylic glass, so any light scratch will show if you got light right in to the lens. I am looking to polish it if it can help.
any light in the field of view is creating big flare, so huge sunshade recommended.

[Paul Cronin]

Giroud could you post some stills to let us compare?

[Tom Hardwick]

I have two of these UWL II lenses and I agree with Giroud - they work very well on camcorders such as the PD170, Z1 and so on. They give a very wide field of view with zero barrel distortion but as he says they're uncoated so flare is a very real problem, especially because as they see so wide they're difficult to hood.

They're also non zoom-through (but allow you to use about 60% of your zoom's reach) and are plastic injection mouldings, so have to be treated with great care. Mind you, many people wear plastic lensed spectacles all day long with no problems.

tom.

[Paul Cronin]

Oh uncoated takes me out of that option. Shooting on the water flare is a real problem even with a great matte box.

[Giroud Francois]

here what my FX1 looks like with and without the lens.
i will post what the camera sees tomorrow. The difference is is really impressive.
The unfinished sunshade is made of thick carton (and is rock solid) to be light as possible because it is used on my glidecam.
http://www.giroud2.com/divers/GA1.jpg
http://www.giroud2.com/divers/GA2.jpg
http://www.giroud2.com/divers/GA3.jpg