Jump to content


Photo

Focus Issues, 35mm ARRI camera


  • Please log in to reply
12 replies to this topic

#1 Tim Carroll

Tim Carroll
  • Sustaining Members
  • 2165 posts
  • Other
  • Chicago, Illinois

Posted 02 June 2008 - 11:34 AM

Got a question for all you folks with experience shooting 35mm. My experience is shooting regular 16 and Super 16 with Arriflex and Aaton cameras, and with those cameras I have not run into this problem.

Lately I've been using an Arriflex 35IIC with a set of Cooke Speed Panchro and Schnieder lenses. I find, when focusing (regardless of the lens on the camera), if I move my eye even slightly off center in the eyepiece, I get alot of ghosting which makes sharp focus really difficult. I may not be using the right term when I say ghosting, it looks like a second blurry image of what I am focusing on, slightly off center from what I am focusing on.

I thought it might be the eyepiece, so I put an ARRI Super Wide Angle eyepiece on the camera and that made it worse (because with the Super Wide Angle I found it much easier to get my eye slightly off center).

Then I put a Jurgen's video tap door on the camera (thinking there might be something screwed up with the original ARRI door), but the same issue was there. If I moved my eye slightly off center in the eyepiece the ghosting came back.

Anyway, what I am trying to find out is if this is the nature of 35mm motion picture cameras? Or older 35mm cameras like the Arriflex 35IIC? Or does it sound like there is something wrong with this particular camera? Like I mentioned, using the same two eyepieces on ARRI 16mm cameras, I don't find that problem.

Any thoughts?

Thanks,
-Tim
  • 0

#2 Dan Goulder

Dan Goulder
  • Sustaining Members
  • 1259 posts
  • Cinematographer

Posted 02 June 2008 - 01:30 PM

You may want to have a qualified technician make sure your ground glass is properly set. Once that has been verified, you may want to use the kind of eyecup (not too cushy) that holds your eye in a consistent place, so that your eyepiece diopter settings don't vary depending upon how hard you're pushing into the eyepiece. It may take some getting used to, but you need to establish a consistency so that you're striking critical lens focusing at the exact same spot in which you're focusing the eyepiece.
  • 0

#3 John Sprung

John Sprung
  • Sustaining Members
  • 4635 posts
  • Other

Posted 02 June 2008 - 02:40 PM

Any thoughts?

I've never seen that with a IIC. Is it the same both with the camera running and stopped?



-- J.S.
  • 0

#4 Tim Carroll

Tim Carroll
  • Sustaining Members
  • 2165 posts
  • Other
  • Chicago, Illinois

Posted 02 June 2008 - 03:03 PM

I've never seen that with a IIC. Is it the same both with the camera running and stopped?
-- J.S.


John,

Yes it is, camera running or stopped. I posted the question a few places and just heard back from a couple of "old" camera guys (they're not really that old but they both have many years of experience with that camera). They said it's normal. Said it was good "operator practice" for me, having to keep my eye exactly centered. Which I appreciate.

Best,
-Tim
  • 0

#5 Hal Smith

Hal Smith
  • Sustaining Members
  • 2280 posts
  • Cinematographer
  • OKC area

Posted 02 June 2008 - 05:03 PM

OT Alert: Which series SP's and how are they intercutting with the Schneiders?
  • 0

#6 Tim Carroll

Tim Carroll
  • Sustaining Members
  • 2165 posts
  • Other
  • Chicago, Illinois

Posted 02 June 2008 - 05:13 PM

OT Alert: Which series SP's and how are they intercutting with the Schneiders?


Hal,

Cooke Speed Panchro Series III 18mm & 25mm, Cooke Speed Panchro Series II 32mm, 40mm, 50mm & 75mm.

I am not inter-cutting them. The Schneiders are not as sharp and warm as the Cookes. I was just using the Schneiders to see if maybe my Cookes were the issue. I LOVE my Cookes, especially now that Guy has serviced all of them. I think I mentioned to you in an earlier post that I now have the complete set, all six of them. Hope to shoot a project with them in the fall. Can't wait.

Best,
-Tim
  • 0

#7 Nick G Smith

Nick G Smith
  • Basic Members
  • PipPip
  • 88 posts
  • Cinematographer
  • London UK

Posted 03 June 2008 - 03:38 AM

I have never had that problem on a 2c.
On the normal eyepiece I find that there is noticeable focus softening at the edges of the gg. This is overcome using a wide angle eyepiece.
I find that there is only one position the eye can be in to see the whole frame. How can you move your eye off centre and see both sides of the frame? Does the ghosting appear when your eye is centred correctly?
Is the ghosting apparent on the gg markings?

I concur with Mr Goulder that you should check the setting of the gg, if you have a spare, swop them over and see if it makes a difference. Otherwise check with a collimater.
Also look at your mirror shutter for any problems.
Your description of the problem makes me think it feels like a slight fogging on the gg or mirror shutter but that sounds far too obvious.

Nick
  • 0

#8 Tim Carroll

Tim Carroll
  • Sustaining Members
  • 2165 posts
  • Other
  • Chicago, Illinois

Posted 03 June 2008 - 05:38 AM

Here is a more detailed description of the issue. The camera still has the light baffles. They don't seem to be effecting anything.

With replacing the eyepiece and the door (using the Super Wide and the Jurgen's door) I have eliminated everything from the IIC viewing system except the diagonal mirror inside the camera housing next to the ground glass (which I cleaned real well), the ground glass itself(which just came from ARRI), and the shutter mirror (which I also carefully cleaned and it doesn't matter which mirrored blade of the shutter is in the viewing position, it occurs with both). Yet the issue still exists.

The best way to describe what I am seeing, I have a Sony radio on my desk, all black except the silver Sony logo. When I focus on the logo, as long as my eye is exactly centered in the eyepiece, the logo is sharp and crisp. If I move my eye even slightly in any direction, I get a ghosting (or blurring or kind of shimmering image) of the logo against the black of the rest of the radio, and the ghosting is just slightly off center from the actual logo. This causes the image to look slightly out of focus.

By carefully moving my eye to get it exactly centered in the eyepiece, I can focus the camera. And the test rolls I have shot have all come out nice and sharp. I just find it annoying and it takes me longer to focus a shot with this weird idiosyncrasy of the ghosting and having to have my eye exactly centered.

Just wondering if this is normal, as I can't think of anything to "fix" on the camera to get it to go away. Like I mentioned, using either of these eyepieces on an Arriflex 16M, 16SR or 16SRII does not create the same problem.


And the response I got from a couple of "old timer camera operators" who used the Arriflex IIC for years "back in the old days" said that was normal on that camera, some quirk with the optics. It's not like the whole image goes to hell, it is just this slight ghosting when your eye is off center, and when you are using really nice glass on the camera, and you are being really picky about focus, it is noticeable, and annoying, at least I found it so.

Best,
-Tim
  • 0

#9 John Holland

John Holland
  • Basic Members
  • PipPipPipPip
  • 2250 posts
  • Cinematographer
  • London England

Posted 03 June 2008 - 10:57 AM

hi tim [old timer] first time i have been called that . :rolleyes:
  • 0

#10 Tim Carroll

Tim Carroll
  • Sustaining Members
  • 2165 posts
  • Other
  • Chicago, Illinois

Posted 03 June 2008 - 11:09 AM

hi tim [old timer] first time i have been called that . :rolleyes:


John,

Used as a term of respect, I assure you.

I am continually blown away by how generous those of you who have been doing this for some time, are with those of us who are trying to learn.

Thank you,
-Tim
  • 0

#11 Patrick Tong

Patrick Tong
  • Basic Members
  • PipPip
  • 40 posts
  • Other
  • HONG KONG

Posted 03 June 2008 - 11:25 AM

Hi Tim

I have the same problem with my IIC....I think it is normal. :(


BTW, Good to hear you got full set of Cooke Speed Panchro
:lol:
  • 0

#12 John Sprung

John Sprung
  • Sustaining Members
  • 4635 posts
  • Other

Posted 03 June 2008 - 01:33 PM

Tim,

Here's a divide and conquer type of idea. Set the camera up on a tripod with a static image that displays the problem. Take the door off and look at the ground glass image using a strong hand magnifying glass. Does that exhibit the problem? I'd guess probably not.

Then take the door and eyepiece, and use them as a sort of low power microscope (which is what viewfinder systems actually are) to look at, say, some fine print in good light, a postage stamp, something like that. Does that exhibit the problem? My guess is that's where it is.




-- J.S.
  • 0

#13 Nick G Smith

Nick G Smith
  • Basic Members
  • PipPip
  • 88 posts
  • Cinematographer
  • London UK

Posted 03 June 2008 - 05:15 PM

So CML are the old timers?!!!!

Tim, I tried to replicate your ghosting issue on my 2C today with a Cooke 20-100 and I do not get any ghost image even if I'm moving my eye to see only half the gg.
It's certainly what you could call a poop viewfinder compared to what you get on modern Arri's.

Nick
  • 0


Opal

Rig Wheels Passport

Media Blackout - Custom Cables and AKS

Broadcast Solutions Inc

Technodolly

FJS International, LLC

Willys Widgets

Wooden Camera

Visual Products

Gamma Ray Digital Inc

CineLab

Ritter Battery

Abel Cine

Metropolis Post

Glidecam

rebotnix Technologies

Paralinx LLC

The Slider

Aerial Filmworks

CineTape

Tai Audio

Abel Cine

CineTape

Metropolis Post

Glidecam

Aerial Filmworks

Rig Wheels Passport

Broadcast Solutions Inc

Opal

Technodolly

Tai Audio

Media Blackout - Custom Cables and AKS

Paralinx LLC

Wooden Camera

Willys Widgets

Ritter Battery

Visual Products

rebotnix Technologies

FJS International, LLC

The Slider

Gamma Ray Digital Inc

CineLab