JVC at OPTEX at DVinfo.net

Martin Costa · May 5th, 2005, 02:37 AM

Hi guys/gals, just thought I'd let you know of a link I came accross on the optex site. Seems they were given a pre-production model to play about with. http://www.prohd.co.uk/

Glenn Gipson · May 5th, 2005, 05:04 AM

I wonder if that adapter and lens would help the camera have a shallower DOF. Does anybody know?

Chris Hurd · May 5th, 2005, 07:03 AM

Sorry Glenn, that's just an an lens mount adapter, very similar to the Canon EF adapter in principle. That adapter housing is much too small to involve a relay lens, therefore it won't preserve depth of field.

Guy Barwood · June 5th, 2005, 04:48 AM

It would preseve DOF wouldn't it? It won't preserve Field Of View though (there will be a significant FOV multiplication factor)

Chris Hurd · June 5th, 2005, 11:56 AM

Nice to see you here, Guy. I wouldn't say that the adapter preserves DOF, because those lenses on a still camera will give you a highly variable deep or shallow depth of field depending on how you use them. But what the adapter does, since it gives you a field of view equal to multiplying the focal length of the lens by a factor of seven times or so, is an extremely shallow depth of field all the time. However its applications are pretty much limited to extreme-telephoto uses, such as wildlife, surveillance, etc. It would be impractical to use in a narrative filmmaking environment because the camera would have to be set up a mile away to get anything other than an extreme close-up.

Guy Barwood · June 6th, 2005, 02:17 AM

With the FOV thats what I was thinking, however with the DOF, I thought it would be the same as using the lens on a 35mm body. So the image seen is just a tight crop of the centre of the image circle, but the DOF of the lens created at a particular setting would be the same as on a 35mm body.

You say a 7x factor, which is a lot indeed, I have a 14mm f2.8 Nikon which would result in a 98mm FOV, but at f2/8 the DOF would be nice and short. Then again the 14mm DOF is pretty long even at f/2.8... If only they could shrink the image circle as well!

Chris Hurd · June 7th, 2005, 07:28 AM

Good points! Too bad we're stuck in "extreme telephoto only" with that option. *frown*

Jacques Mersereau · June 7th, 2005, 08:08 AM

Quote:

Originally Posted by Chris Hurd

Good points! Too bad we're stuck in "extreme telephoto only" with that option. *frown*

***DROOL*** :)

May 5th, 2005, 02:37 AM	#1
Martin Costa Regular Crew Join Date: Feb 2005 Location: London UK Posts: 76 Images: 2	JVC at OPTEX Hi guys/gals, just thought I'd let you know of a link I came accross on the optex site. Seems they were given a pre-production model to play about with. http://www.prohd.co.uk/

May 5th, 2005, 07:03 AM	#3
Chris Hurd Obstreperous Rex Join Date: Jan 2001 Location: San Marcos, TX Posts: 27,366 Images: 513	Sorry Glenn, that's just an an lens mount adapter, very similar to the Canon EF adapter in principle. That adapter housing is much too small to involve a relay lens, therefore it won't preserve depth of field. __________________ CH Search DV Info Net \| 20 years of DVi \| ...Tuesday is Soylent Green Day!

June 5th, 2005, 11:56 AM	#5
Chris Hurd Obstreperous Rex Join Date: Jan 2001 Location: San Marcos, TX Posts: 27,366 Images: 513	Nice to see you here, Guy. I wouldn't say that the adapter preserves DOF, because those lenses on a still camera will give you a highly variable deep or shallow depth of field depending on how you use them. But what the adapter does, since it gives you a field of view equal to multiplying the focal length of the lens by a factor of seven times or so, is an extremely shallow depth of field all the time. However its applications are pretty much limited to extreme-telephoto uses, such as wildlife, surveillance, etc. It would be impractical to use in a narrative filmmaking environment because the camera would have to be set up a mile away to get anything other than an extreme close-up. __________________ CH Search DV Info Net \| 20 years of DVi \| ...Tuesday is Soylent Green Day!

June 7th, 2005, 07:28 AM	#7
Chris Hurd Obstreperous Rex Join Date: Jan 2001 Location: San Marcos, TX Posts: 27,366 Images: 513	Good points! Too bad we're stuck in "extreme telephoto only" with that option. frown __________________ CH Search DV Info Net \| 20 years of DVi \| ...Tuesday is Soylent Green Day!

May 5th, 2005, 05:04 AM	#2
Glenn Gipson Major Player Join Date: Jan 2003 Location: Plainfield, New Jersey Posts: 927	I wonder if that adapter and lens would help the camera have a shallower DOF. Does anybody know?

June 5th, 2005, 04:48 AM	#4
Guy Barwood Major Player Join Date: Mar 2005 Posts: 423	It would preseve DOF wouldn't it? It won't preserve Field Of View though (there will be a significant FOV multiplication factor)

June 6th, 2005, 02:17 AM	#6
Guy Barwood Major Player Join Date: Mar 2005 Posts: 423	With the FOV thats what I was thinking, however with the DOF, I thought it would be the same as using the lens on a 35mm body. So the image seen is just a tight crop of the centre of the image circle, but the DOF of the lens created at a particular setting would be the same as on a 35mm body. You say a 7x factor, which is a lot indeed, I have a 14mm f2.8 Nikon which would result in a 98mm FOV, but at f2/8 the DOF would be nice and short. Then again the 14mm DOF is pretty long even at f/2.8... If only they could shrink the image circle as well!