Zoom conversion

12 replies [Last post]
Mick jenner
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Joined: Dec 8 2000

Could somebody give me an idea as to the 35mm equivalent on a 17x7 + x2 converter lens with a 2/3 mount stepped down with a 2/3-1/3 adapter on a camera with 3 x 1/3 chips. i.e the maximum zoom.

Many thanks

Mick

MAGLINK
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Joined: Mar 8 2007

Is it 42? ;)

Mick jenner
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Joined: Dec 8 2000

Hi Gary,

Many thanks,the number 42 sounds ok, but but what I was hopeing for was the 35mm equivalent i.e 1000mm 0r 2000mm etc

Mick

MAGLINK
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Joined: Mar 8 2007
Mick jenner wrote:
Hi Gary,

Many thanks,the number 42 sounds ok, but but what I was hopeing for was the 35mm equivalent i.e 1000mm 0r 2000mm etc

Mick

Sorry Mick I was having a joke and hadn't a clue what your focal length could be but at least we all know that 42 is the answer to everything else? :D

foxvideo
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Joined: Sep 9 1999

I think this table will give you the info you need - click on the PDF link on the page:

http://pro.jvc.com/prof/attributes/features.jsp?&feature_id=01&model_id=MDL101617

Dave Farrants Fox Video Editing

Mick jenner
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Joined: Dec 8 2000

Hi Dave,
Thanks for the link, when I can work out how to use it hopefully my question will be answered.

Hi Gary,
You have jut made my day, now when ever I am asked my age it will be!

Mick

Barry Hunter
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Joined: Nov 30 2001

Born on the 29th Feb? :-)

Barry Hunter videos4all.org

Nigel Longman
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Joined: Apr 28 1999
Mick jenner wrote:
Could somebody give me an idea as to the 35mm equivalent on a 17x7 + x2 converter lens with a 2/3 mount stepped down with a 2/3-1/3 adapter on a camera with 3 x 1/3 chips. i.e the maximum zoom.

Many thanks

Mick

Right Mick - before we start I must ask you to realise that it's Sunday pm and I've had a good lunch and a few glasses of some rather nice Shiraz - so I wouldn't place any money on the following.

But......a 17x7 lens means a 17mm wide setting with a zoom ratio of 7. Soooo the telephoto focal length is 7x17=119mm. Now from the table that Dave indicated, a focal length of 119mm on a 2"/3 chip is about 468mm 35mm equivalent. But you're going to use that lens on a 1"/3 chipped camera, so I believe you have to double the equivalent focal length giving a final answer of 936mm.

My best shot. Regards, Nigel

Mick jenner
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Joined: Dec 8 2000

Hi Nigel,

Many thanks for that, I will let you get back to sleeping off your lunch time excesses!!!

Mick

Piotr
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Joined: Jun 9 2006

17mm would be a very narrow "wide " on 2/3, something like 68mm on 36x24mm film equivalent.
Perhaps the lens is 17x/7mm ??

Nigel Longman
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Joined: Apr 28 1999
Piotr wrote:
17mm would be a very narrow "wide " on 2/3, something like 68mm on 36x24mm film equivalent.
Perhaps the lens is 17x/7mm ??

Morning all.

Piotr I think you're right - the focal length is 7mm with a 17x zoom range. I quoted it the wrong way round in my post yesterday.

Fortunately however I don't think that will change the final answer I gave above because the telephoto focal length would still be 17 times 7mm, ie 119mm.

So I'll still go with about 936mm. But I'd still get that checked by an expert Mick ;) .

Cheers, NL

Ben Longden
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Joined: Jun 10 2009

I was thinking much the same...
900 odd mm that is...

Mick jenner
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Joined: Dec 8 2000

Thanks all for your help, much apprieciated

Mick