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Focus and shutter on EX1

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Sverker Hahn
Focus and shutter on EX1
on Feb 26, 2008 at 8:54:05 am

Finally my EX1 has arrived. Expecting the FCP Studio upgrade this week. Right now I am just playing with camera. I really like it and look forward to use it in serious work. But ...

... I do not quite get this shutter thing. (My Canon has four settings - full auto, auto shutter, auto iris and manual. That was so easy to understand.) In TLCS menu I can set Auto Shutter on/off, the Shutter Button also and in Direct Menu I can select Shutter Auto and Shutter Off. Why is it so complicated? How do you pros use shutter settings it? (I am not yet in the "pro" gang ...)

About focus: somewhere I read "no creeping". Since I have had clips destroyed by focus change in warm conditions with my Canon XH-A1, I liked that. But is it true? Is it impossible to have unwanted focus change with Full MF?

Sverker Hahn, Stockholm

Slower is better!

EX1
Canon XH A1
iMac Intel
Final Cut Studio


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Craig Seeman
Re: Focus and shutter on EX1
on Feb 26, 2008 at 3:25:58 pm

Yes the EX1 is a complex camera. It offers many choices and options.

As a Pro my objective is to get the best looking footage. I rarely use auto anything but it can be a necessity in certain shooting circumstances.

Shutter Off means shutter equals frame rate basically. In PAL area that means shutter is 1/25.

I'd NEVER use auto shutter for anything.

Focus I use Manual (servo) or Full Manual (servo disabled - focus ring pulled towards me). That terminology confuses some though.

Auto Focus can be good for tracking an object in which focus in constantly changing. The EX1 seems to track moving objects very well. In other words if people move past (behind) trees as they walk, the camera will stay focused on the people. That's why the EX1's "slow" reaction is good. It does NOT jump from object to object as you track something. Auto Focus might also be good when tracking an object (that's typically changing its focal point) at a sporting event for example too. Otherwise I don't use auto focus.

Push Focus (pushing the little button under Focus switch) only works in servo Manual. This is something I've used in the past with other cameras. In some cases it's faster to do this than fumble with the focus ring. What those cases and conditions are depends on the shooter and situation of course. In other cameras, Push Focus grabs the focus and holds when you let go of the button. It seems in the EX1, once you hit Push Focus it will continue to hunt even after you let go. This can be problematic for some since the camera, not your finger, is making the decision as to when the subject is in focus.

Manual Focus Assist. This works in Manual servo. It means after you focus camera may make fine adjustments. I don't want camera to correct my judgement so I NEVER use this.

If you want to use Macro mode you must be in Manual servo. Macro does not work in Full Manual (servo disabled).

TLCS. I NEVER use it and have removed it from my LCD menu. I avoid auto anything except as noted above. It controls various auto functions.



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Sverker Hahn
Re: Focus and shutter on EX1
on Feb 26, 2008 at 4:42:30 pm

Thanks, Craig.

Yes, I like working in manual mode. These days I tend to take looong scenes without panning, without focus changes and were there is very little movement. Quite extreme, yes. But for this I think that the EX1 is the perfect camera, at least the best for under $10K.

As for the shutter, I get the thing with Shutter OFF.

And I will work with Full Manual Focus. The reason I asked was:

- beautiful flowers in full sunlight. I wanted 60 minutes of the same scene (miniDV). Activated manual focus on the Canon XH-A1 in order to get the flower to the left in the picture in focus. It was a closeup, 1 m and tele. Composition was perfect, and I left the camera for 60 minutes.

- only 7 minutes was ok, and the rest was useless, since focus shifted to another flower.

In the Canon manual it is mentioned that one cannot count on manual focus staying, since heat building up in the camera may change focus.

So, I like the EX1 Full Manual Focus feature which gives a more reliable impression than manual servo focus.

But still, is it possible that internal heat or sunshine on a black camera may cause focus drift?

With the camera released during winter on the northern hemisphere, perhaps it is people in the southern hemisphere that have experiences of this?



Sverker Hahn, Stockholm

Slower is better!

EX1
Canon XH A1
iMac Intel
Final Cut Studio


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Craig Seeman
Re: Focus and shutter on EX1
on Feb 26, 2008 at 5:10:36 pm

I've certainly heard weather (temperature/humidity) can impact focus so heat build up may impact that too. Metal, Plastic, Glass are all affected. I've heard experienced DPs will note that the focus distance marks on the lens should really only be considered a guide because they will be slightly off based on the shooting conditions.

If your question is whether you'd use Auto Focus to compensate for the above I'd suspect the best answer is no. Another similar situation might be shooting a time lapse over several hours from day through twilight to night. In some areas, even here in NYC, there can be a significant drop in temperature. Even if the AF made such subtle adjustments you have to consider what would happen if a bird or insect moved through the focal path during that time.

My own guess is that if the camera and lens are really well designed being on one hour shouldn't have a significant impact on focus (but who knows what "significant" is depending on how one is shooting).



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Sverker Hahn
Re: Focus and shutter on EX1
on Feb 26, 2008 at 6:45:32 pm

So I cannot be certain to avoid focus drift, even with EX1? At least I hope it won´t destroy any clips like it did with the flowers. I will take reasonable precautions when I take clips with shallow depth of field - shading the camcorder, check focus now and then. The EX1s LCD screen is so good that focusing is quite easy, and the expanded focus works even during recording.

Thanks for the input, Craig.



Sverker Hahn, Stockholm

Slower is better!

EX1
Canon XH A1
iMac Intel
Final Cut Studio


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Craig Seeman
Re: Focus and shutter on EX1
on Feb 27, 2008 at 12:45:39 am

[Sverker Hahn] "So I cannot be certain to avoid focus drift, even with EX1?"

Best way to know for sure is to do a test. The lens is a very good one and might withstand changes in temperature.






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