HVX's stock lens question

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Panamaniac
I was just talking to my DP trying to get him up to speed with the equipment for a short we are shooting in a week. When we were talking about the lens he asked me about the focus ring.

I told him it is a ring that spins endlessly and it's movement feeds information to a servo which controls the focus of the lens. I also told him it was, however, designed so focus is repeatable over and over again so markings on the ring will work.

Then he asked me something else which I will try to explain hoping you will figure out what he was trying to get at.

He wanted to know if when you zoomed in to focus and then you zoomed back out for your framing, if the depth at which you achieved perfect focus would remain the same.

I wasn't 100%, so I brought up how your DoF becomes longer as you zoom out, and so there wont be a problem, as the more you zoom out more and more of your frame gets into focus...

I would like to give him the actual answer to his question, as it seems there are different types of lenses and he is trying to figure out exactly what he will be working with... He knows lenses, he's been making a good living for over 10 years out here in LA as a 1AC in prime-time, Block-Busters, you name it... so I would love to be able to give him the exact answer.

Please help!
 
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Sounds like he's asking that if he zooms in, focuses at say 50ft, then zooms back out will the focus stay locked at 50ft. Then answer is yes as I'm sure you know. I think hes just wanting to make sure he can zoom in to focus accurately then zoom back out to frame and the shot will still be in focus.
 
I told him it is a ring that spins endlessly and it's movement feeds information to a servo which controls the focus of the lens. I also told him it was, however, designed so focus is repeatable over and over again so markings on the ring will work.
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It is repeatable as long as you don't turn the camera off. If you do, you will have to reset the markers. I use little bits of "sticky note" with arrows on them.
 
Dick Campbell said:
It is repeatable as long as you don't turn the camera off. If you do, you will have to reset the markers. I use little bits of "sticky note" with arrows on them.
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This is what I knew and I told him about it... I didn't say it would be re-set if we turned the camera off but I figured that would happen.

jdajda said:
Sounds like he's asking that if he zooms in, focuses at say 50ft, then zooms back out will the focus stay locked at 50ft. Then answer is yes as I'm sure you know. I think hes just wanting to make sure he can zoom in to focus accurately then zoom back out to frame and the shot will still be in focus.
Click to expand...

This is what he wanted to know, and I though it was so, but I was afraid to answer... so long as the focus stays locked on a distance regardless of zoom position then the answer is YES...

THANK YOU GUYS! He is 5min away and I feel I can safely tell him I got his answer! :)
 
no... it is not manual (mechanic) if you play with it you'll notice that it spins for-ever

the zoom is though
 
It is precise, and fully repeatable as a manual focus would be. But, it does spin forever, and it isn't 'true' manual, no. But, it behaves exactly as if it were.

Jason
 
You're right. I have a cavision follow focus on mine with a hard stop, so to me it doesn't spin forever. I forgot. It is very repeatable, though.
 
Jason, i wouldn't say exactly as if it were cause no matter how accurate it is, it still doesn't feel like a real one...
 
Oh, yes I do. I'm just reading closely cause I want to be 100% about my knowledge before I make myself look bad with this guy.

Thanks for posting!
 
But don't try to use a tape measure to set focus, as the distances in the viewfinder are a figment of Panasonic's imagination
 
same here, every time.

Barry also talked about using a laser measuring device...I've got one, also works really well with the focus ring.
 
Zoom in and focus is about the only way I've been able to focus this baby properly. If your DoP likes using a bit of boost for focusing, he can turn on the EVF DTL (2nd button from left at the back) as well.
 
well, I dunno, but I was filming in a hall that I know is 45' long, cam to focus point 40' or so, the cam kept saying 59'+. In fact when I set the known distance using the vf display, the image was noticably out of focus, using evf detail, and shooting in SD (To match other cams). the lens was zoomed in full to be sure of the focal distance. Not trying to start a war here, only recount my experiance.
Dave
 
guys, I just bumped into a problem... I don't understand why it hasn't come up before, or maybe it did and I missed it...

when racking with marks on the lens, if I go far and then try to come back to the same mark the distance read won't be the same?!?

I was told that this is also a problem with several other HVX's...?!? is this something we know about?

Please help me have this figured out before Friday (first production day)
 
Hmmm... How far off are the numbers? I'll double check mine tonight and post results but I'm pretty sure its repeatable.
 
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