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-   -   WA lens comparisons (https://www.dvinfo.net/forum/sony-vx2100-pd170-pdx10-companion/8195-wa-lens-comparisons.html)

Bryan Beasleigh March 30th, 2003 11:15 PM

WA lens comparisons
I did a search and read all of the back posts on WA adapters. My budget says Kenko but my gut says Optex or Century. I'm looking at using the Century or Lee combo hood and filter holder on either.

Mike, I was particularly interested in your comments about the Century. Did you ever do the tests?

Mike Rehmus March 31st, 2003 11:01 AM

No, Brian, I haven't. The new PD150 has been in use so much I haven't had time to play with it. Not a bad idea though. Just a minute . . . .

OK, here's what I just tested. Camera feeding a 27" television via S-Video. Focus on a table with newspaper, and three-dimensional targets using the Century at about mid-zoom. View the image, then remove the Century and re-zoom for the same visual field.

'Clearly', the image without the Century is sharper. Is it a problem in the real world? Probably not if the camera is used in the widest zoom position. Up close? I'd prefer the 'naked' lens.

What I don't know is what is a good test in this case. Zoom or move the camera to get the same visual field? I'll ask Century what they recommend.

Between the participants of this group, we probably own all of the available WA adapters, let's try and test them.

We first need to design the test. I'm thinking of a color target that we can reproduce in our studios from an image attached to an email. Then we set up and shoot stills with identical setups and then post the results. I can hide the pics on my web site so we can look at them. Or perhaps DVIC has a place where we can post. Chris?

#1. Who will volunteer to run tests on their adapter? We can have multiple testers for each adapter brand.

#2. We need to design a test target. It can be either a flat target (probably the best choice for this).

#3. We need to decide on camera settings with which to make the test. I suggest an f-stop of about 2 stops less than max. I don't think shutter speed will effect the results if the camera is held steady on a tripod. Probably should use natural light from behind the camera. No filters. What else?

#4. We might as well try different camera modes while we are at it and answer the question about still-image quality at the same time.

What else?

Wayne Orr March 31st, 2003 12:15 PM

I would think you would want some wide shots with vertical lines to look for distortion. (I think all zoom through lenses exhibit some distortion.) Also full tite shots to check focus.

Mike Rehmus March 31st, 2003 12:41 PM

I've sent the question off to Century.

But in reality, we should check out the adapters in a simulation of the way we prefer to use them.

So add your comments please.

Bryan Beasleigh March 31st, 2003 06:06 PM

I found a broadcast house in toronto that is the Canadian dea;ler for the OpTex .65. I'm really tempted. I'm a big kid when it comes to patience.

Wayne what's your opinion on this lens?

Wayne Orr March 31st, 2003 07:02 PM

Excellent high quality lens, Bryan. I know the BBC uses their products, which I guess isn't all that surprising considering they are a British company. I would opt for the bayonet mount, which lists at $299.00, US. Pick up a Flarebuster for another $25 from www.flarebuster.com while you decide if you want a simple sunshade or mattebox. A "best buy."

BTW, Bryan, I know you are a member of the VX2K forum at Yahoo. If you look in the "photos" gallery on the left of their page, you will find a couple of photos taken with the "Optex." They aren't great, but you will get an idea of the amount of distortion you can expect, which is about average for a zoom through .65. There are also photos from other lenses in other folders, including some from the Sony .75 from yours truly.

Bryan Beasleigh March 31st, 2003 07:31 PM

Kingsway Motion Picture are the canadian distributors for OpTex. their price is $495 canadian, which works out about the same or slightly less than shipping on in from the US. If we had true free trade it wouldn't be such a hassel. 298 plus UPS second day (Fed Ex is close) comes to $500 to $510 Canadian. If I buy from the US and have a problem it becomes a logistical nightmare.

Since the century is $829 here this sounds like a better deal. To land the lens from the US is 657 Canadian. Someone's getting rich and it ain't me. If i don't get the optex I order the century from the US and take my chances. Ouch!!

Can you imagine, the wife just came into my office and wanted me to clean it up. How insulting !

Tom Hardwick April 1st, 2003 04:00 PM

Yes, any test between lenses should compare barrel distortions by having a 4:3 rectangle close to the edge of the frame. Also there should be a vignetting test. The Cavision 0.65x vignettes the full DV frame when used on the VX2k, and so does the Tecpro 0.65x.

I agree a couple of stops down from max aperture is a good place to shoot, although my tests show that at smaller apertures (f8 for instance) the soft edges of some converters sharpen up and match the centre definition more. Mind you, diffraction is taking its toll at f8, so it's gains and losses here.

Then there's flare to consider. Generally the more elements and the cheaper the lens the more flare is produced into the light because savings are made on the lens the coatings. Some manufacturers only multi-coat the entrance and exit pupil surfaces (the most important ones), leaving the inner glass surfaces completely uncoated.

Some lenses have useful filter threads, some don't. Some come with lens caps that stay on, others have caps that fall off when the day gets just slightly warm. Feeble.


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