View Full Version : Rack Focus While Zooming?


J.J. Kim
January 5th, 2008, 11:51 PM
Hi, ya'll.
I recently got my very 1st camera and I picked XH A1, and I am very happy with my decision.
One thing I notice when I went to shoot in downtown chicago (just for fun), I was not able to change my focus while I was zooming out... I was using button for the zoom (not the ring), and trying to focus with ring...
solution???
thank you all ahead for lots of help.

JJ

Happy new Year!!

Chris Soucy
January 6th, 2008, 12:08 AM
You can't.

You need to zoom in to the target, focus, and then zoom out.

Focus cannot be changed whilst zooming, as there is one motor to do both - it can either zoom or focus, not both.

If focus is correct at zoom in, it will be correct at zoom out.

If you wish to change the focus subject whilst zooming, you need an interchangeable manual system lens, which the A1 cannot support.

CS

PS. If set to "IAF" focus, the lens does seem to do some strange things whilst zooming, especially if it can't lock onto a specific target. Sometimes it will track perfectly, sometimes go all over the place trying to figure it out. How it can do this when there is supposedly only one motor has me bewildered.

Peter Jefferson
January 6th, 2008, 10:10 PM
Instant AF works much like the Canon D-SLR range.. in fact, its as fast to focus as an F4 lens on crop camera body like a 40D. Its not super fast like a 5D, but fast enough for video in any case. Once its tracked the subject. I would have thought the IR of a 580EX would have assisted this kind of focus in low light, but sadly the A1 doesn't support IR focus.

In any case, as mentioned, you cannot focus and zoom at the same time.

Daniel Epstein
January 7th, 2008, 09:06 AM
Unadvertised Feature/Defect

John Estcourt
January 7th, 2008, 10:25 AM
Is this unique to the canon or is it the same for the Z1 etc and is it the same when in auto focus.( I know its frowned on but sometimes it has its uses)
Could rule out the A1 for me..shame oh well helps to narrow down my choice of camera.

Richard Hunter
January 7th, 2008, 06:21 PM
Is this unique to the canon or is it the same for the Z1 etc and is it the same when in auto focus.( I know its frowned on but sometimes it has its uses)
Could rule out the A1 for me..shame oh well helps to narrow down my choice of camera.

The Z1 focus and zoom are independent. One of the Z1 features that almost persuaded me to buy one is the shot transition, where you can set up 2 different zoom levels and focus points, and transition from one set to the other in a specified time. The Canons can do focus OR zoom, but not both together, and the transition time is much faster than many people would like.

Richard

John Estcourt
January 8th, 2008, 01:18 AM
thanks for the reply richard...that really is a deal breaker for me..shame.
oh well the list gets shorter.

Peter Jefferson
January 8th, 2008, 06:39 AM
The Z1 focus and zoom are independent. One of the Z1 features that almost persuaded me to buy one is the shot transition, where you can set up 2 different zoom levels and focus points, and transition from one set to the other in a specified time. The Canons can do focus OR zoom, but not both together, and the transition time is much faster than many people would like.

Richard


Agreed 100%, as for beaing a deal breaker, if you let this issue dictate your decision, then you're missing out on something really special. There is more this camera than this one feature... believe me...

Richard Hunter
January 8th, 2008, 06:51 AM
thanks for the reply richard...that really is a deal breaker for me..shame.
oh well the list gets shorter.


Hi John. Everybody has their own needs from a video cam. For me, I bought the A1 rather than the Z1 because I prefer the image I get from the A1. It means I have to work with (or around) the A1's limitations, but that would be the case no matter which cam I chose. They all have their limitations.

BTW, I am originally from Midlothian. Which part of Scotland are you in?

Richard

John Estcourt
January 8th, 2008, 07:45 AM
hi Richard I am living in South Ayrshire.
As im typing this I am looking out of my window across the sea to the island of Arran and on a good day northern Ireland, however on a day like this singapore sounds preferable!
Your right about compromises as I have been looking to upgrade to HiDef it has become very clear that no one camera fullfills all my needs and I could spend all my time researching and still never happy.
So my decision is made(I think...ha..ha)but unfortunately It wont be the A1
although it was initially my first choice.
all the best john

J.J. Kim
January 8th, 2008, 10:25 PM
thank you all for the help.

Richard Hunter
January 8th, 2008, 11:15 PM
hi Richard I am living in South Ayrshire.
As im typing this I am looking out of my window across the sea to the island of Arran and on a good day northern Ireland, however on a day like this singapore sounds preferable!
Your right about compromises as I have been looking to upgrade to HiDef it has become very clear that no one camera fullfills all my needs and I could spend all my time researching and still never happy.
So my decision is made(I think...ha..ha)but unfortunately It wont be the A1
although it was initially my first choice.
all the best john

You're making me homesick John. My only comfort is that I don't have to scrape frost off my car windows here, I hate it when my fingers turn blue.

Richard

Cary Lee
January 9th, 2008, 12:56 AM
Agreed 100%, as for beaing a deal breaker, if you let this issue dictate your decision, then you're missing out on something really special. There is more this camera than this one feature... believe me...


I agree...Just one feature missing shouldn't make you jump ship to the other..You need to really evaluate the positives vs the negatives when purchasing. There are work around for this feature...IE using a 35mm adapter with a follow focus on a zoom lens can give that feature, not to mention the DOF that looks like film. But that is a considerable additional cost you must consider in your budget.