fixed focul adapter vs. zoom through converter at DVinfo.net

Dylan Couper · June 3rd, 2002, 11:17 AM

Newbie question alert!!!
What's the difference between a wide angle fixed focul adapter and a zoom through converter lens?

I got a price list from Cavision (who are conveniently located 30 mins from my house) on their wide angle lens options, here it is for those of you who are interested.

Industrial series - Converters (zoom-through)
PWC06X72 Three-element 0.6X zoom through converter for lenses with a 72mm P=0.75 filter thread (and under). $480.00

Industrial series - Adapters

PWA06X72 Single-element 0.6X wide-angle adapter for lenses with a 72mm P=0.75 filter thread (and under). Slightly smaller front for use by itself. $199.00
PWA06X72II Single-element 0.6X wide-angle adapter for lenses with a 72mm P=0.75 filter thread (and under). Has 95mm front for use in combination. $199.00
PWA042X72 Two-element combination of BWA07X95 & PWA06X72II $558.00
PFA03X72B Two element 0.3X fish-eye adapter with Canon XL1 bayonet mount $595.00

I also got prices on matte boxes if anyone is interested, I'll post them.

Jeff Donald · June 3rd, 2002, 06:37 PM

Hi,

A Wide Angle fixed focal adapter is used with the lens set to it's widest position. The lens cannot be zoomed or vignetting may occur. A zoom through converter allows the lens to be zoomed and no vignetting will occur.

Jeff

Dylan Couper · June 3rd, 2002, 11:07 PM

Thanks.
That's pretty much what I figured.

I guess I will be getting the fixed focul adapter, and just moving the camera closer when I have to instead of zooming.

Any reason I would want to spend $400 more on the zoom through, besides not having to screw on, and unscrew the regular adapter or moving the camera closer manually?

Jeff Donald · June 3rd, 2002, 11:29 PM

Certain shots almost demand the zoom thru feature, but $400 is pretty steep. Have you looked at what Century http://www.centuryoptics.com/ has to offer? I have used a great deal of their optics over the years and have rarely been disapointed.

Jeff

Josh Bass · June 19th, 2002, 07:55 PM

I was wondering about this. . .I think the convereter I looked at increased by the . . .um. . .hmm. . ."framage" by one third, if I read right. Is this the most a converter increases the um. . .hmm. . .angle of view?

Jeff Donald · June 20th, 2002, 05:32 AM

Hi,

Are you looking for a wide angle or a telephoto converter? They are usually marked as 1.5 or 2 and those are for the telephoto range and will magnify the image by the marked factor. A 100mm lens with a 2x converter is like a 200mm lens. If the converter is for wide angle they are marked .7, .5 or .3 even. Use the factor to determine the change (100mm with a .5 is like a 50mm lens). Some of the adapters are for max zoom or max wide angle only. You can't zoom the lens with the adapter on.

I can highly recommend the Century http://www.centuryoptics.com/ adapters. I have used them since the late 80's and i have never been disapointed by them. Presently, i am looking at a wide angle adapter for my Canon 3x lens. What's holding me back? Well, like everyone else, the cost. Century adapters aren't cheap.

Jeff

Charles Papert · June 20th, 2002, 11:22 AM

The usual problems with fixed-focal length wide angle converters is that they do not maintain focus when you zoom in, either immediately or at a certain point on the zoom. In some instances, adjusting the back focus will bring the focus back to a useable mode at the wider range of the lens, but as soon as you zoom it will need tweaking again.

If a wide angle converter works at the widest focal length without vignetting (darkening at the corners caused by the lens "seeing" its own barrel), it will not start to vignette when zoomed in.

Josh Bass · June 20th, 2002, 06:40 PM

Right. I was wondering if someone knew a good converter. The one I keep hearing about is the century (optics?) converter, but then I read that this requires you to remove all filters and the lens hood to use it. Any way around that?

Charles Papert · June 20th, 2002, 07:04 PM

Josh, all wide-angle converters need to mount as close as possible to the lens they are modifying to avoid distortion and, well, vignetting! Thus they will all require removal of filters and lens hood. Ideally you would be able to replace the filters by using a mattebox that is wide-angle enough to allow placement in front of the conveter without--uh--vignetting. The 3x3 filter size that seems to have some popularity in the DV world will most likely not suffice, you would be looking at at least a 4x4 or a 4.5 aka series 9 (round) filter set for a .6 or .7x converter, and probably a 6x6 for a .5x converter (you don't want to imagine how much the rental on those plus the mattebox will run!) Alternatively, you can carefully tape filters onto the front of the converter, but it's time consuming and messy.

Century Precision makes a really good product, I think it is the best in its class.

Josh Bass · June 20th, 2002, 08:05 PM

But isn't the lens hood kind of necessary, filters aside?

Charles Papert · June 20th, 2002, 09:19 PM

The sole function of a lens hood is to keep extraneous light from hitting the front element of the lens and causing flares, which it is marginally good at achieving. A matte box is much better. Taping filters onto the front element means you will have to take extraordinary care to block said light, using flags or an improvised hood made of blackwrap or something.

Josh Bass · June 20th, 2002, 10:20 PM

Hmm.

Jeff Donald · June 21st, 2002, 01:18 PM

If you think about it, hoods are mostly useless. Why? The hood is only effective at the widest angle of your zoom lens. If it were effective at preventing stray light at max telephoto it would cause vignetting as you zoomed the lens wider. But, damn, they sure look cool. The mattebox is a better solution, as Charles pointed out. The Image 2000 http://www.birnsandsawyer.com/index.asp is a decent box and is made to work with the Century adapters (95mm). You might check with the sponsors, but I think it is a B & S exclusive.

Jeff

June 3rd, 2002, 11:17 AM	#1
Dylan Couper Wrangler Join Date: Jun 2002 Location: Vancouver, British Columbia Posts: 8,314	fixed focul adapter vs. zoom through converter Newbie question alert!!! What's the difference between a wide angle fixed focul adapter and a zoom through converter lens? I got a price list from Cavision (who are conveniently located 30 mins from my house) on their wide angle lens options, here it is for those of you who are interested. Industrial series - Converters (zoom-through) PWC06X72 Three-element 0.6X zoom through converter for lenses with a 72mm P=0.75 filter thread (and under). $480.00 Industrial series - Adapters PWA06X72 Single-element 0.6X wide-angle adapter for lenses with a 72mm P=0.75 filter thread (and under). Slightly smaller front for use by itself. $199.00 PWA06X72II Single-element 0.6X wide-angle adapter for lenses with a 72mm P=0.75 filter thread (and under). Has 95mm front for use in combination. $199.00 PWA042X72 Two-element combination of BWA07X95 & PWA06X72II $558.00 PFA03X72B Two element 0.3X fish-eye adapter with Canon XL1 bayonet mount $595.00 I also got prices on matte boxes if anyone is interested, I'll post them.

June 19th, 2002, 07:55 PM	#5
Josh Bass Slash Rules! Join Date: Apr 2002 Location: Houston, Texas Posts: 5,472	I was wondering about this. . .I think the convereter I looked at increased by the . . .um. . .hmm. . ."framage" by one third, if I read right. Is this the most a converter increases the um. . .hmm. . .angle of view? __________________ The Bass' camerawork The Bass on IMDB

June 20th, 2002, 11:22 AM	#7
Charles Papert Wrangler Join Date: Jan 2002 Location: Los Angeles, CA Posts: 6,810	The usual problems with fixed-focal length wide angle converters is that they do not maintain focus when you zoom in, either immediately or at a certain point on the zoom. In some instances, adjusting the back focus will bring the focus back to a useable mode at the wider range of the lens, but as soon as you zoom it will need tweaking again. If a wide angle converter works at the widest focal length without vignetting (darkening at the corners caused by the lens "seeing" its own barrel), it will not start to vignette when zoomed in. __________________ Charles Papert www.charlespapert.com

June 20th, 2002, 06:40 PM	#8
Josh Bass Slash Rules! Join Date: Apr 2002 Location: Houston, Texas Posts: 5,472	Right. I was wondering if someone knew a good converter. The one I keep hearing about is the century (optics?) converter, but then I read that this requires you to remove all filters and the lens hood to use it. Any way around that? __________________ The Bass' camerawork The Bass on IMDB

June 20th, 2002, 07:04 PM	#9
Charles Papert Wrangler Join Date: Jan 2002 Location: Los Angeles, CA Posts: 6,810	Josh, all wide-angle converters need to mount as close as possible to the lens they are modifying to avoid distortion and, well, vignetting! Thus they will all require removal of filters and lens hood. Ideally you would be able to replace the filters by using a mattebox that is wide-angle enough to allow placement in front of the conveter without--uh--vignetting. The 3x3 filter size that seems to have some popularity in the DV world will most likely not suffice, you would be looking at at least a 4x4 or a 4.5 aka series 9 (round) filter set for a .6 or .7x converter, and probably a 6x6 for a .5x converter (you don't want to imagine how much the rental on those plus the mattebox will run!) Alternatively, you can carefully tape filters onto the front of the converter, but it's time consuming and messy. Century Precision makes a really good product, I think it is the best in its class. __________________ Charles Papert www.charlespapert.com

June 3rd, 2002, 06:37 PM	#2
Jeff Donald Warden Join Date: Mar 2002 Location: Clearwater, FL Posts: 8,287	Hi, A Wide Angle fixed focal adapter is used with the lens set to it's widest position. The lens cannot be zoomed or vignetting may occur. A zoom through converter allows the lens to be zoomed and no vignetting will occur. Jeff

June 3rd, 2002, 11:07 PM	#3
Dylan Couper Wrangler Join Date: Jun 2002 Location: Vancouver, British Columbia Posts: 8,314	Thanks. That's pretty much what I figured. I guess I will be getting the fixed focul adapter, and just moving the camera closer when I have to instead of zooming. Any reason I would want to spend $400 more on the zoom through, besides not having to screw on, and unscrew the regular adapter or moving the camera closer manually?

June 3rd, 2002, 11:29 PM	#4
Jeff Donald Warden Join Date: Mar 2002 Location: Clearwater, FL Posts: 8,287	Certain shots almost demand the zoom thru feature, but $400 is pretty steep. Have you looked at what Century http://www.centuryoptics.com/ has to offer? I have used a great deal of their optics over the years and have rarely been disapointed. Jeff

June 20th, 2002, 05:32 AM	#6
Jeff Donald Warden Join Date: Mar 2002 Location: Clearwater, FL Posts: 8,287	Hi, Are you looking for a wide angle or a telephoto converter? They are usually marked as 1.5 or 2 and those are for the telephoto range and will magnify the image by the marked factor. A 100mm lens with a 2x converter is like a 200mm lens. If the converter is for wide angle they are marked .7, .5 or .3 even. Use the factor to determine the change (100mm with a .5 is like a 50mm lens). Some of the adapters are for max zoom or max wide angle only. You can't zoom the lens with the adapter on. I can highly recommend the Century http://www.centuryoptics.com/ adapters. I have used them since the late 80's and i have never been disapointed by them. Presently, i am looking at a wide angle adapter for my Canon 3x lens. What's holding me back? Well, like everyone else, the cost. Century adapters aren't cheap. Jeff

June 20th, 2002, 08:05 PM	#10
Josh Bass Slash Rules! Join Date: Apr 2002 Location: Houston, Texas Posts: 5,472	But isn't the lens hood kind of necessary, filters aside? __________________ The Bass' camerawork The Bass on IMDB

June 20th, 2002, 09:19 PM	#11
Charles Papert Wrangler Join Date: Jan 2002 Location: Los Angeles, CA Posts: 6,810	The sole function of a lens hood is to keep extraneous light from hitting the front element of the lens and causing flares, which it is marginally good at achieving. A matte box is much better. Taping filters onto the front element means you will have to take extraordinary care to block said light, using flags or an improvised hood made of blackwrap or something. __________________ Charles Papert www.charlespapert.com

June 20th, 2002, 10:20 PM	#12
Josh Bass Slash Rules! Join Date: Apr 2002 Location: Houston, Texas Posts: 5,472	Hmm. __________________ The Bass' camerawork The Bass on IMDB

June 21st, 2002, 01:18 PM	#13
Jeff Donald Warden Join Date: Mar 2002 Location: Clearwater, FL Posts: 8,287	If you think about it, hoods are mostly useless. Why? The hood is only effective at the widest angle of your zoom lens. If it were effective at preventing stray light at max telephoto it would cause vignetting as you zoomed the lens wider. But, damn, they sure look cool. The mattebox is a better solution, as Charles pointed out. The Image 2000 http://www.birnsandsawyer.com/index.asp is a decent box and is made to work with the Century adapters (95mm). You might check with the sponsors, but I think it is a B & S exclusive. Jeff