Focus while dollying

You could put an indiFOCUS follow focus and a set of indiRAILS with 12" carbon fiber rods on for $398 and shipping.
With the hard stops, you can set them at 32 and 99, thus ensuring that you don't focus outside the limits and reset your marks. And because the standard indiFOCUS has a friction wheel, no modifications are needed to the camera.
There are 12" and 18" whips also...
 
Hey FocusThis,
Do you have an IndiFocus? are you affiliated with them? How is the IndiFocus Pro (the one with the gears? how does it work with Nikon lenses and a RedRockMicro M2?
Anyone else recommend any follow focus. (I've heard good things about the chroziser, but man I can't spend over 1k for a follow focus)
 
One final question

One final question

Thanks again for everyone's advice. As always, DVXusers are there to help a fellow filmmaker in need.

Focus This - The indiFocus does look like the way to go. I've heard good things (though not yet with the A1 yet).

One final question (for those that own an A1)

How easy do you find it to focus manually with the A1's smaller LCD screen. Am I doomed to have to purchase a Marshal field monitor? I'm hoping for my short film projects I (or my focus puller) can use the attached LCD effectively.

Look forward to your response.

Peter
 
The A1 doesn't have repeatable focus. Using a follow focus with it is going to be infinitely more difficult than it would on a unit with repeatable focus.

The LCD seems plenty fine for accurate focusing, provided you combine it with the peaking and magnified focus assist. But be aware that you can't use the magnified focus assist while recording, so using it during your dolly shot will be much more difficult without a full-screen monitor.
 
Repeatable focus

Repeatable focus

Hi Barry.

Does the HVX has repeatable focus? There seems to be conflicting information. Would you mind clarifying? Thanks.

Also, if the IndiFocus has mechanical hard stops, I'm wondering why repeatable focus would be difficult? Set focus at point A, set focus at point B, move between, repeat.

Am I missing something?

Thanks again,

Peter
 
Me Myself & I said:
Does the HVX has repeatable focus? There seems to be conflicting information. Would you mind clarifying? Thanks.
Click to expand...
Yes, the HVX and JVC HD100 both have precisely repeatable focus. No other HD camera under $10,000 does (unless you put a true manual lens on an XLH1, but the stock lens isn't repeatable).

Also, if the IndiFocus has mechanical hard stops, I'm wondering why repeatable focus would be difficult? Set focus at point A, set focus at point B, move between, repeat.

Am I missing something?
Click to expand...
Yes, you're missing that the XHA1's focus ring isn't repeatable. So if you execute your move on the IndiFocus once, at one speed, you'll get one result. Execute that same move at a slightly different speed and you'll get a different result. There is no direct correlation to how the focus ring moves, and how the internal lens elements move.

Most cameras have vague non-precise servo rings, and the XHA1 is no exception. You cannot use it by itself to get guaranteed accurate repeatable results. And using an IndiFocus or some other type of follow focus is just adding another piece of equipment to the mix without addressing the fundamental problem.

The HD100's focus ring is a physical manual focus ring. Move it to one position and it's focused at a certain distance; move it to another position and it's focused to another certain distance, and any time you move the ring to those points, those will be the focus points you hit. The HVX's ring can perform exactly the same way. It's based on a servo design but is precisely calibrated to mimic the exact behavior of a true manual focus ring. The other cameras aren't, and cannot be relied on in that same fashion. I mean, you can very, very, very gradually move the canon's focus ring, and actually get it to turn all the way around the lens without ever affecting the internal focus position. If you move it slowly enough that it's under the "threshhold" where the motor detects the motion and moves the focus elements, you can move it well, well off the mark. Which makes it completely useless for trying to set focus points and rack between them.


Maybe if you used the Console program to control the Canon via remote firewire connection you could get precise repeatable focus, but it's impossible to repeat a focus move using the camera's focus ring. That's why they include that "focus preset" gimmick, to try to overcome that limitation, but I find it unusable in an actual production environment, and certainly not appropriate for a dolly move where the speed of your dolly isn't guaranteed.
 
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Hey Barry,
What's your take on using DV Rack as a field monitor with a follow focus device (maybe the indiefocus or the redRockMicro) and a 35mm adapter (I haver the M2) as far as workflow. I know DV rack has a slight delay. Do you use the DV Rack to mark your Focus Ring prior to the takes and then use the follow focus marks while shooting? How does that work. I'm very concerned with the slight delay of the DV rack, but since I haven't worked on a film yet, maybe its not an issue because the field monitor is only needed to mark focus prior to filming and not so crucial while filming.
 
DV Rack's delay is slight with the HVX or DV, but it's interminable with HDV. HDV introduces about a half-second of delay before it spits its data out the firewire, so any delay you're noticing in DV Rack by itself, well, grow it by 1/2 second if using HDV.

As such, no, you wouldn't want to use DV Rack as a monitor with an HDV camera for a focus move. And it's not all that easy to use it for that purpose even with a frame-discrete system like DV or HVX. With an HVX or DVX I'd use DV Rack's monitor to set the start and end focus points, and then use those to set the focus during the shot (plus, with the HVX you can turn on the magnified focus assist during the shot, provided you can frame around it).

For HDV, I don't know how you're going to pull it off without a proper monitor. No HDV camera lets you use magnified focus assist during the shot, and none of them other than the HD100 allow for precise repeatable focus.

If someone put a gun to my head and said "pull off this move on an HDV camera without a monitor", I'd have no choice but to try the focus preset gag on the Z1 or XHA1/XLH1. Set the start and end points and then let it "do its thing" of automatic focus shift, and then you have to just hope and pray that your dolly grip is moving the dolly at an appropriate speed to match the change in focus that the lens is doing on its own, because without a production monitor you can't monitor it during the shot.

Well, in a case like that, actually DV Rack might be okay because someone could be watching the monitor and tell you if you lost focus during the shot or not (even though it's delayed). But it's going to be hit or miss. It would be better to rely on the camera's distance readout than to rely on trying to mark marks on the ring.
 
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Thanks for the quick reply Barry. I have the HVX and the delay though slight is still noticible. Its just I'm trying to use the DV rack as a field monitor with my HVX so I can capture to it also. This would allow me to do away with the Firestore FS-100, solve the issue of flipped image, and battery power for a portable monitor. I guess it would only be an option for a Film Like workflow where the focus stops are set prior to filming. I'm even working on a way to attach the laptop to my camera. if it all works I might even sell the bracket or the whole system Laptop, Bracket, External HD as a package for those who rather kill two birds with one stone and be able to expand storage cheaply.
 
Barry_Green said:
Yes, the HVX and JVC HD100 both have precisely repeatable focus. No other HD camera under $10,000 does (unless you put a true manual lens on an XLH1, but the stock lens isn't repeatable).

How do you do a repeatable focus on the HD100? Are you talking about a programmable function that does this, or is it manual? I always just have to look at the lens markings to do this. Is this what you're talking about?
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Wow.

Just when I thought I'd made the right decision.

Barry, your statement about repeatable focus makes me think the A1 is useless for narrative work. I mean, racking focus from someone in the foreground to someone in the background is the backbone of narrative film making (and least in my experience).

Is there a solution? As much as I'd love to, I can't buy the HVX because of the P2 cards, and I really thought the A1 was the answer. Any thoughts you may have would be greatly appreciated.

Thanks

Peter
 
what do you mean you can't buy the HVX because of the P2 card? Do you mean the price of the cards? or the limited amount of shooting. Because narrative film making has historically been done on film which requires to change magazines. So this shouldn't be an issue. As far as Price I agree with you, they are expensive. But also consider that they now have a free 8gb P2 card included. (at least I think they still have that promotion. better hurry. though you will have to wait some weeks before getting the card)
 
Actually, I read that the A1 does have repeatable focus. In fact the A1 lets you program focus stops and switch between them electronically.
 
The Canon XH-A1 manual is available from Canon here. (Click on Product/Support Manuals)

On Page 37 they describe Focus Preset:
"This function enables a focus setting to be memorized and to return to that focus setting instantly. You can also select the speed at which the camcorder returns to the preset focus setting."

As for the focus being repeatable, I don't see anything in the manual to prove or disprove that but I read a detailed post on a board a few days ago (wish I could find it) that claimed it is fully repeatable.
 
Marco,
I'm just guessing here, but what I think is the issue is that you cannot repeat focusing just rotating the ring around the lense. because the servo mechanism accelerates differently if you move the ring at different speeds. Hence people say you cannot repeat focus. but if you set the focusing stops in the menus of the camera then you have hard stops at the begining and at the end. This would also take a really long time to do while on a set and I'm not sure if you can have more than 2 stops. in case you had 3 subjects in your scene all at different distances from the lense.
 
Me Myself & I said:
Barry, your statement about repeatable focus makes me think the A1 is useless for narrative work. I mean, racking focus from someone in the foreground to someone in the background is the backbone of narrative film making (and least in my experience).
Peter
Click to expand...

Racking focus is just a tool used by a film maker to be able to direct the viewers attention to a particular spot within the frame. It is by no means the "backbone" of narrative film making. If you are basing your film making career on such a statement you will be sadly dissapointed.
First and foremost the script is the backbone of narrative film making.
 
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