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Zooming while shooting video on a DSLR

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Sunil Situnayake
Zooming while shooting video on a DSLR
on May 1, 2010 at 3:12:41 am

In the manual for the Canon EOS Rebel T21 it states, "If you use a lens whose aperture changes while you zoom, you should not zoom while shooting a movie. Zooming while shooting a movie may record changes in the exposure." Could someone please tell me what lenses I could use to be able to zoom while recording a movie?


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Noah Kadner
Re: Zooming while shooting video on a DSLR
on May 1, 2010 at 12:04:52 pm

Any lens that gives multiple f-stop ratings in its description will do this- i.e. Canon EF 70-300mm f/4.5-5.6 lens- means it will change f-stop if you zoom during a shot. This only will happen if you're wide open- i.e. at the maximum aperture of the lens.

This is not a huge deal- just be aware of it when you zoom. It's a consequence of using lenses designed for still work for video instead. If you want to avoid this entirely look for zoom lenses with constant apertures like- Canon EF-S 17-55mm f/2.8 IS USM.

But these are usually more expensive because they are more mechanically/optically complex to make. So I'd suggest you just learn to live with this very minor limitation of the DSLR world...

Noah

Check out my book: RED: The Ultimate Guide to Using the Revolutionary Camera!
Unlock the secrets of 24p, HD and Final Cut Studio with Call Box Training. Featuring the Sony EX1 Guidebook, Panasonic HVX200, Canon EOS 5D Mark II and Canon 7D.
Watch Formosa- My indie movie shot with the SDX900 and finished with Final Cut Studio.


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Bob Cole
Re: Zooming while shooting video on a DSLR
on May 1, 2010 at 12:54:27 pm

[Noah Kadner] "This only will happen if you're wide open- i.e. at the maximum aperture of the lens."

minor correction - it can also happen if you're close to wide open, depending on how far you zoom in.

Question, as a non-DSLR user: on a video camera you can see the "t/stop" change as you zoom in while wide (or close to wide) open. Do DSLR cameras give you the same notification in the viewfinder?


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Noah Kadner
Re: Zooming while shooting video on a DSLR
on May 1, 2010 at 6:20:28 pm

Yeah it's lowest common denominator- you'll switch to whatever is the f-stop that the camera can do at a particular zoom setting. Or you can simply lock the exposure at a stop more closed to avoid this from happening. I.e. pick the slower number of the range listed on your lens' maximum f-stop range.

Noah

Check out my book: RED: The Ultimate Guide to Using the Revolutionary Camera!
Unlock the secrets of 24p, HD and Final Cut Studio with Call Box Training. Featuring the Sony EX1 Guidebook, Panasonic HVX200, Canon EOS 5D Mark II and Canon 7D.
Watch Formosa- My indie movie shot with the SDX900 and finished with Final Cut Studio.


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Brandon Morris
Re: Zooming while shooting video on a DSLR
on May 6, 2010 at 2:54:37 pm

so if I have my standard 18-55 lens from the t2i kit, whats the lowest/highest f/stop I should stay at?

Brandon Morris
http://www.brandonmorris.com
I  my Mac's.


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Bob Cole
Re: Zooming while shooting video on a DSLR
on May 6, 2010 at 3:40:37 pm

[Brandon Morris] "whats the lowest/highest f/stop I should stay at?"

It's complicated, but if you want to be safe, and don't feel like learning the actual limits for a given focal length, just set your aperture no wider than f/5.6. (don't use f/3.5 except for wider angles)

I'm saying this based on a photo of the lens, so run a test.


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Noah Kadner
Re: Zooming while shooting video on a DSLR
on May 6, 2010 at 4:08:09 pm

Also understand the kit lens is pretty much the worst quality lens you can get. :) A nice 50mm would be the next thing to get. Primes do not suffer from this issue because they have non-variable f-stops.

Noah

Check out my book: RED: The Ultimate Guide to Using the Revolutionary Camera!
Unlock the secrets of 24p, HD and Final Cut Studio with Call Box Training. Featuring the Sony EX1 Guidebook, Panasonic HVX200, Canon EOS 5D Mark II and Canon 7D.
Watch Formosa- My indie movie shot with the SDX900 and finished with Final Cut Studio.


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Brandon Morris
Re: Zooming while shooting video on a DSLR
on May 18, 2010 at 8:42:48 pm

Yeah I noticed that when I was testing it on my San Francisco trip.
What are some good affordable lenses to look for?
Is the Canon EF 75-300mm f/4-5.6 III ok?

Brandon Morris
brandonmorris.com
i  my mac.


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