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Lens flare issue


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#1 Rolfe Klement

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Posted 20 July 2005 - 03:50 PM

Just got some rushes back and I have a weird lens flare - any idea what it is?

It seems to hang around in the top left of frame

Lens Flare

thanks

Rolfe
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#2 Nathan Milford

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Posted 20 July 2005 - 04:29 PM

What make and model of camera?
What make and model of lens?
Where did you have it processed and transfered?

Could you see it in the eyepiece? I imagine not because it's ghastly and the DP aught to have noticed. If that's the case turn the shutter out of reflex position and put some scotch tape over the gate and inspect it with a magnafying glass while you pan the camera across a light source. If its only coming from the top of the frame (bottom of the gate) it might be light kicking off of the back of shutter and it might need to be painted. If it comes from all four sides it may be gate flare. But knowledge of the type of camera might be able to kelp us help you better.
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#3 Stephen Williams

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Posted 21 July 2005 - 03:13 AM

Just got some rushes back  and I have a weird lens flare - any idea what it is?

It seems to hang around in the top left of frame

Lens Flare

thanks

Rolfe

<{POST_SNAPBACK}>


Rolfe,

Almost certanly the gate edge is shiny metal and not black. The white pillers just out of screen flare as you pan. I have had this problem in the past with effects shots. Ive seen the problem with older Aatons, Photosonocs, and Mitchell cameras. When I can take the apeture plate out of the camera I have often used candle smoke to matt down the edges. This caused much ammusement on CML a couple of months ago!

Stephen Williams DP
Zurich

www.stephenw.com
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#4 Rolfe Klement

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Posted 21 July 2005 - 03:45 AM

Yeap - it is my old Arri 11C. I will check the gate. The camera is getting more and more use and maybe it (the gate) needs checking. It doesn't seem to happen much when I shoot with no matte box - but I am not certain of that.

So basically should I check the gate for missing black sections. What kind of paint should I use if it is the case

thanks

Rolfe
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#5 Stephen Williams

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Posted 21 July 2005 - 04:00 AM

Yeap - it is my old Arri 11C. I will check the gate. The camera is getting more and more use and maybe it (the gate) needs checking. It doesn't seem to happen much when I shoot with no matte box - but I am not certain of that.

So basically should I check the gate for missing black sections. What kind of paint should I use if it is the case

thanks

Rolfe

<{POST_SNAPBACK}>



Hi,

Arri 2's can have baffle issues, (if they are removed) also what lens are you are using? When using lenses designed for still photography the risk increases as the coverage is twice the size required.

I would look for any shiny edges or missing paint inside the camera. A Black Pental pen is a start. I use the mattest black paint I can find. I assume the gate is full apeture so a few microns of paint wont show! Take care not to get paint on the mirror or GG!

Stephen
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#6 Sam Wells

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Posted 22 July 2005 - 08:33 AM

Arri 2's can have baffle issues, (if they are removed) also what lens are you are using? When using lenses designed for  still photography the risk increases as the coverage is twice the size required.Stephen

<{POST_SNAPBACK}>


This was my first question when I viewed it, were the baffles removed.

If you are using long lenses / still camera lenses this certainly can be a problem.

It sorta looks too big to be off plate bounce to me but I could be wrong.

-Sam
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#7 Rolfe Klement

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Posted 23 July 2005 - 02:25 AM

I should clear up this baffles issue on Arri 2's - based on my experience

The camera was in at Arri a couple of weeks ago and they 100% guarentee that you can pull all the baffles out and it will not cause any problem. I have heard this from Otto Nemenz (LA) who have a huge collection of 2C's used in rental by Deakins etc over the years. I have seen many cameras both Arri Pans and rental stock cameras here and in the US with no baffles and they all work fine. My camera has only ever had 2 baffles and it has been fine.

In fact most people ask for the baffles to be taken out cause it makes the Video assist look terrible.

The issue around what people think are the baffles is actually the GG holder is the mounting section - it needs blocking. I will get some photos on the web so it is easy to see. Most people used to use 1 inch electrical tape (including Kubrick etc)

I have had a good look inside the camera and I have 2 sections where the paint has come off and is silver. On the lens side of the body by the centre of the mirror rotation and also in the top cavity above the GG holder.

I will post some photos when I get the batteries charged in my digi.

I use Arri primes only (16mm T2.1: 25mm T1.3, 40mm T2.1 and 85mm T1.3) all the lenses have been checked and are OK.

I use the arri LMB - the light matt box that screws onto the front of the lenses. I thought it might be the filters but the effect occurs when I don't have any filters in - but it might be the filter holders?

Any ideas - I will try post the pictures asap

thanks

Rolfe

Edited by Rolfe Klement, 23 July 2005 - 02:27 AM.

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#8 Rolfe Klement

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Posted 23 July 2005 - 03:30 AM

Here are the photos

Image 1 : First the scruffing on the body by the mirror mechanism
Posted Image

Image 2 : Below the flecks inside the body - NOTE : the camera is upside down - so this is on the GG side
Posted Image

Image 3 : Below the camera from the front
Posted Image

Image 4 : Below the gate from the back
Posted Image

Image 5 : The tape for the baffles - note I have 2 baffles only (maybe I should tape the 2 triangles top and bottom)
Posted Image

Hope this helps the fault finding

thanks

Rolfe
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#9 Stephen Williams

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Posted 23 July 2005 - 04:52 AM

Here are the photos


Rolfe

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Rolfe,

The apeture plate edges are silver (image 3+4). I would start with a black Pental pen on those, and cover the silver flecks elsewhere.

One other point, any shiny metal bits near the back of the lenses can also cause pain.

Good luck

Stephen
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#10 Rolfe Klement

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Posted 27 September 2005 - 05:23 AM

forgot to update this with the result. Took the Camera into Arri and they ran a test - very simple but perfect. The problem was caused by a light leak where the magazine sits on the camera body on the non- operator side - added some black tape thing and hey presto fixed

thanks

Rolfe
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#11 Stephen Williams

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Posted 27 September 2005 - 05:29 AM

forgot to update this with the result. Took the Camera into Arri and they ran a test - very simple but perfect. The problem was caused by a light leak where the magazine sits on the camera body on the non- operator side - added some black tape thing and hey presto fixed

thanks

Rolfe

<{POST_SNAPBACK}>


Hi,

I would still get that pental pen on the apeture plate edge!

Stephen
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#12 Dimitrios Koukas

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Posted 27 September 2005 - 05:53 AM

forgot to update this with the result. Took the Camera into Arri and they ran a test - very simple but perfect. The problem was caused by a light leak where the magazine sits on the camera body on the non- operator side - added some black tape thing and hey presto fixed

thanks

Rolfe

<{POST_SNAPBACK}>


And the huge flare coming form the direction of the sun was thru the magazine, opposite operator's side??
I know that the image is recorded inverted there but...
Dimitrios Koukas
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#13 Rolfe Klement

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Posted 27 September 2005 - 06:43 AM

nope - that was a issue on the matt box

well spotted though

thanks

Rolfe
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