Sony tele adapter question at DVinfo.net

Charlie Webster · April 5th, 2004, 03:57 PM

just got the

VCL-HG1758

for my pd-170

the zoom is great and sharp, but when i pull all the way back to full wide i get a curved black croping effect on the edges

what do you call this?

is it normal?

ty

charlie

Don Bloom · April 5th, 2004, 05:20 PM

It's called vignetting (vin-yet-ing) I said it once and my mother (85 years) said, "nice to hear speaking Yiddish for a change"

Anyway, Yeah, it's "normal" on a lot of lens attachments. Some are better than others, some are WAY better than others and some don't have any BUT if you know what the lens does and at what point it does it, you should be able to avoid it.

Don

Tom Hardwick · April 6th, 2004, 08:23 AM

Hey Charlie - you've bought a telephoto converter to extend the focal length of your PD170 from 72mm to 122.4mm. If you need a wider angle of view, best to remove said lens.

Charlie Webster · April 6th, 2004, 01:02 PM

hehe ty guys really appreciate your replies.

i have to say i don't get it- I buy a sony lens which seem to be especially for this camera and i get vignetting.

maybe it's unaviodable.

Sure i can take the lens off and put the wide adapter on.

but it'simppossible to know how much i can zoom out untill i get the vignetting.

that means extra work on my nle system.

did i get the wrong lens?

PS after doing a search i see everyone has this issue with all tele lenses :(

oh well at least i don't have to sell the dang thing

Tom Hardwick · April 6th, 2004, 01:48 PM

I have a Canon C8 1.4x teleconverter that doesn't vignette at all whatever the zoom position, so if your requirement is that you *must* have full zoom capabilities, then yes, you bought the wrong lens Charlie.

There's nothing wrong with the lens itself though - it's actually designed to vignette the image as you zoom back. It could've been designed with much bigger elements so as to not to vignette, but it would have been heavier, more expensive and a lot bigger. They wouldn't sell many. My C8 is big and it's a pretty mild 1.4X, so I don't use it much.

And remember - if you stick a lens in front of your camcorder - ANY lens, then you'll degrade the image quality. There's no getting away from this basic law of optics.

tom.

April 5th, 2004, 03:57 PM	#1
Charlie Webster Regular Crew Join Date: Apr 2004 Location: Sun Valley, Idaho Posts: 81	Sony tele adapter question just got the VCL-HG1758 for my pd-170 the zoom is great and sharp, but when i pull all the way back to full wide i get a curved black croping effect on the edges what do you call this? is it normal? ty charlie

April 5th, 2004, 05:20 PM	#2
Don Bloom Inner Circle Join Date: Jan 2003 Location: Chicago, IL Posts: 6,609	It's called vignetting (vin-yet-ing) I said it once and my mother (85 years) said, "nice to hear speaking Yiddish for a change" Anyway, Yeah, it's "normal" on a lot of lens attachments. Some are better than others, some are WAY better than others and some don't have any BUT if you know what the lens does and at what point it does it, you should be able to avoid it. Don

April 6th, 2004, 08:23 AM	#3
Tom Hardwick Inner Circle Join Date: Mar 2003 Location: Billericay, England UK Posts: 4,711	Hey Charlie - you've bought a telephoto converter to extend the focal length of your PD170 from 72mm to 122.4mm. If you need a wider angle of view, best to remove said lens.

April 6th, 2004, 01:02 PM	#4
Charlie Webster Regular Crew Join Date: Apr 2004 Location: Sun Valley, Idaho Posts: 81	hehe ty guys really appreciate your replies. i have to say i don't get it- I buy a sony lens which seem to be especially for this camera and i get vignetting. maybe it's unaviodable. Sure i can take the lens off and put the wide adapter on. but it'simppossible to know how much i can zoom out untill i get the vignetting. that means extra work on my nle system. did i get the wrong lens? PS after doing a search i see everyone has this issue with all tele lenses :( oh well at least i don't have to sell the dang thing

April 6th, 2004, 01:48 PM	#5
Tom Hardwick Inner Circle Join Date: Mar 2003 Location: Billericay, England UK Posts: 4,711	I have a Canon C8 1.4x teleconverter that doesn't vignette at all whatever the zoom position, so if your requirement is that you must have full zoom capabilities, then yes, you bought the wrong lens Charlie. There's nothing wrong with the lens itself though - it's actually designed to vignette the image as you zoom back. It could've been designed with much bigger elements so as to not to vignette, but it would have been heavier, more expensive and a lot bigger. They wouldn't sell many. My C8 is big and it's a pretty mild 1.4X, so I don't use it much. And remember - if you stick a lens in front of your camcorder - ANY lens, then you'll degrade the image quality. There's no getting away from this basic law of optics. tom.