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-   -   Best Telextender Lens for VX2100?? (https://www.dvinfo.net/forum/sony-vx2100-pd170-pdx10-companion/26844-best-telextender-lens-vx2100.html)

Steve McDonald June 1st, 2004 01:20 AM

Best Telextender Lens for VX2100??
 
I need some references from those who have telextender lenses on a VX2100/PD170 or their predecessor models. Do the Sony 1.7X HG or the Century Precision Optics 2X perform well? A main concern is at what point in the zoom range do they begin to vignette? Has anyone tried the Century Optics 76mm telex lens with 1.6X, on the VX2100? It's the one you'd use with the DVX100, which has a basic 72mm lens. With a 58mm-76mm step-up ring, would you avoid most of the vignetting?

I tested my Raynox DCR-2020PRO telextender today on my VX2100 and its images were sharp and bright, even at 2.2X and 26.4X total. But, it's so long-barreled, it vignetted in all but the top 10% of the zoom range. This makes it a specialty lens only and not very usable for general shooting.

I have a 55mm, 1.4X telextender I use on another digital camcorder that has a 37mm lens, for 25.2X total. This wider telex barrel causes vignetting in only the bottom 1/4 of the zoom range and I can leave it on the camera for most of my shooting. It'd be nice to have a telextender for the VX2100 that didn't vignette any more than that. Much of my shooting is of wildlife, that rapidly ranges from very far to very near.

Steve McDonald

Dave Largent June 2nd, 2004 04:19 AM

Well, the Sony starts vignetting at the 50% mark,
but it *is* a good lens.

Steve McDonald June 2nd, 2004 05:53 AM

Dave, looking at the picture and the specs of the Sony HG 1.7X lens, I guessed that it would give you the outer half of the zoom range, vignette-free. It's 10mm wider than the Century Optics 2X lens at the outer barrel, 90mm to 80mm, which would make a difference in this factor.

I've had several camcorders with which I used telextenders that were wider at the mounting threads than the outer end of the basic lens. Using step-up adaptor
rings with this type of configuration, I always had 2/3 to 3/4 of the top end of the zoom range, without vignetting.

What this group of 58mm camcorders needs, is a highgrade 2X extender that is about 68mm wide at the mounting threads and 95mm wide at the outer end, to reduce the vignetting range down to perhaps the bottom 1/4 only. This would make it much more usable in more situations. I miss using my Canon L-1 in Hi-8 days. It gave me 30X with the 2X under-the-lens extender and no vignetting at any point. At a track meet it was a superstar, at a time when that was all the image quality I expected.

Tom Hardwick June 2nd, 2004 12:31 PM

My Canon C8 (1.4x tele-extender) is completely zoom through but a) It's pretty mild at 1.4X and b) it comes with huge diameter glass, and a 67mm attachment thread.

But I'd say this: If you want to shoot at 72mm, then take the tele-extender off and realise the full potential of your camcorder's lens. In other words don't worry too much if the tele extender isn't zoom through, you'll not be wanting to zoom with it on anyway, will you?

tom.

Steve McDonald June 2nd, 2004 06:17 PM

Tom, the Canon C8 1.4X telextender you mentioned is interesting, if you can go through the full zoom range with it. I've never encountered it before. Is it a video accessory lens or intended for still-camera use? I have two Canon 1.4X extenders at 46mm and 55mm mounting-thread sizes, but they're too small for a 58mm basic lens.

This C8 1.4X with a 67mm thread, might work as an intermediate lens, to use in the range between the basic 12X and the 26.4X I get with my 2.2X extender.

Taking an extender on and off frequently is not an option when shooting flying birds, sports events, etc. I'd miss most of the action and wear out the mounting threads, doing that.

Tom Hardwick June 3rd, 2004 12:25 AM

Yes, I know what you mean Steve. The C-8 is a lump, weighing in at 400g with adapter ring to take it's 67mm thread down to 58mm. There's no front filter thread but the front element is deeply hooded. Even so it really cries out for a 100mm clamp-on hood.

Although I got the lens brand new last year, I suspect that it had lain unsold for years on a dealer's shelf. My guess is it's 20 years old, and was made to extend the range of Canon's Super-8 cameras.

I should correct myself here. On the VX2000 it's not full zoom through, putting semi-circles of cutoff into the frame at w/a. On my Panasonic MX300 It is zoom through for all practical purposes, because TV masking hides the vignetting I get at full wide.

tom.

Steve McDonald June 3rd, 2004 04:08 AM

Thanks for the details on the C-8, Tom.
You got lucky finding this, as it's probably an extinct species nowadays.
At 400gm., it's actually no heavier than the 58mm Sony or Century Optics telextenders.

I found a one-of-a-kind gem about 16 years ago. It's a Telesor .5X wide-angle with a 58mm mounting thread. It was in a film camera shop, although it's labeled as a video lens. It gives a flawless image with no distortion or vignetting at any point. And, it fits the VX2100 exactly and works well with it. It's
very solid at 280gm. and cost $160. (in
1988 $$). I wish there were more of them, for any of you who'd want one, but I suspect they are no longer for sale. I haven't been able to find one and I've uncovered only a couple of references to the Telesor name. It is apparently a
marketing brand name used by a Japanese lens company, that is primarily known by another name. Or, Telesor may be a brand name used by a U.S. company for products made for it in Japan.

Incidentally, I found a special way to attach my old Canon TL-55 telextender to my VX2100. This add-on lens gives 1.4X, for 16.8X total zoom. The way I mount it, it vignettes in only the bottom 38% of the zoom range, despite having a smaller, 55mm mounting thread. This is a very usable, intermediate zoom range, filling the niche between either having just the 12X basic lens or attaching my 2.2X Raynox telextender (26.4X total).

If I used a 58mm-55mm step-down adaptor ring to mount the TL-55, it would stick out 1 cm farther and would vignette in the lower 55% of the zoom range. Instead, I fit its male mounting threads loosely (but snugly) inside the female 58mm threads of the VX2100. I installed two split fishing rings in two pairs of tiny holes I drilled in its upper rim. I stretch two loops of black surgical tubing from the rings, around the obvious spots on the camera. These hold it nicely in place. The upper loop uses a little S-hook on one end.

It looks a bit gerry-rigged, but that extra 17% of usable zoom range makes a lot of difference. I can pop off the rubber loops and the extender more quickly for closeups or wide shots, than I could unscrew a thread mount.

The Canon TL-55 and the two smaller versions of it they sell, are not expensive, but have excellent optical quality. I paid $125. for mine in 1988, but now, it sells for $90., mailorder.

I plan to also buy one or the other of the Sony 1.7X or Century Optics 2X telextenders. I'm hoping that someone will tell me at what point in the zoom range the Century lens will cause vignetting on the VX2100.

Tom Hardwick June 3rd, 2004 12:23 PM

You say you think I got lucky, but it's a lump to carry around for those few extra mm Steve. Goes up to 100.8mm and is still a long way off Canon's 20x zoom on the XM2 (GL2).

And just to be painfully pedantic and to clear up a misunderstanding that a lot of people have, fitting a wide-angle or tele-converter does *not* increase your zoom range. It's still a 12x zoom - all you've done is shift the limits, either up or down.

Worse, you say you've got a 26.4x with the Raynox 2.2x teleconverter, whereas in fact you've probably only got a 4x zoom now - due to the vignetting that takes place so early on.

But this is the bit that gets me all excited. You say, "Telesor .5X wide-angle with a 58mm mounting thread. It gives a flawless image with no distortion or vignetting at any point."

You mean that? a 0.5x (zoom through?) with no barrel distortion? None? Sorry squire, but I just don't believe you
: ¬)

tom.

Dave Largent June 3rd, 2004 08:23 PM

I know what you mean, Tom. I've heard pros who
use the Canon wide say that it has *no* vignetting.
But I *want* to believe Steve. I think I've heard the Telesor
name come up before. You guys shouldn't bring up this
exotic stuff. You know how I was about TecPro.

Steve McDonald June 3rd, 2004 11:38 PM

Too bad we can't post pictures here. I've tested the Telesor WA on large objects with long, straight, horizontal and vertical lines. There was not a hint of any curving at the edges. I've used it on half a dozen camcorders and a digital still camera. Their basic lenses were 37/49/52/55/58mm and all the way through their zoom ranges, no vignetting.

It has a 75mm-wide outer barrel and is just 46mm (1 27/32-inches) long.

Today, on another video group, an experienced video pro and tester of equipment, partially answered my question about the Sony 1.7X HG and the Century 2x. He said that the Sony is the only telextender of which he knows, for the VX cameras, that gives a sharp image throughout the zoom range. The only reference he made about the Century, was by way of complete ommission. He was vague about just where the vignetting starts with either lens.

You can bet that if I get my hands on one of these, I'll put up exact results about this issue, testing under different light levels, which affects the point where vignetting starts. When the iris is open wider, during lower light, vignetting increases, as light from farther out from the lens center enters.

Dave Largent June 4th, 2004 06:41 AM

So how much are you selling that Telesor for?

Steve McDonald June 4th, 2004 07:47 AM

Sorry, Dave, but I will part with the Telesor when it's pried from my-----well,
you know the rest of that line. I suppose I should specifically bequeath it in my will. I have a grand-nephew who's getting into some serious video----but hopefully he'll be an old man by the time I'm gone.

Dave Largent June 4th, 2004 02:39 PM

Steve, why don't you post and ask that guy if
he's ever taken a look at the Century tele? Wonder what
he says about it.
I know the Century name is well regarded, but I've heard
talk that their wide is soft.
If you really wanted to know specifically about the
Sony vignetting I could look into it. Like I've related,
it appears on the LCD screen at approximately
the halfway point. I'd be surprised if it varies much
based on iris opening.

Steve McDonald June 5th, 2004 08:07 AM

The expert evaluator about the telextender lenses has communicated with me again and has reiterated his sterling opinion of the Sony HG 1.7X. He says it's sharp and tight in its performance and outdoes any telextender application he's encountered.

He said he's not tested the Century Optics 2X lens. But, he has used two of their different wide-angles on an XL1 and was not impressed. He said the results from them were "soft". But, he suspected the fault may have been with the camera, not the wide-angle lenses.

It'd looking more and more like the Sony 1.7X HG will be the one added to my gear.


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