Red Tests in Germany

[redapple]

Hi there,

I´m working for a German Camera Rental, we`ve ordered five red`s, will delivered at November, we hope......
Yesterday we do the first test with a Red from Amsterdam....

First, the look from the camera is amazing. But the Camera we get was just in a beta stadium.......

We do some lens tests with Zeiss HS Primes (18,35,85), also with Arri Master Primes (18,40) and a Angenieux 25-250 Zoom Lens......

Master Primes looks great.....also the Zeiss HS.......

But we found a lot of bugs here......

1. The Camera has no mark where the sensor is, so from where i should
measuring my distance??? This is much important for a camera with a
super 35 sensor, 1 or 2 cm can be completly out of focus...
Has Red forget this??????

2. The next thing is, all the lense scales doesn`t work...and also different
with different focal distance.............???
The only reason for this can be, that the sensor isn`t on the right
Position, that have to be 52.000mm at all Film Cameras.......
We read, this is happend to 2 or 3 other users also.....And Red doing
replacements for their cameras.....but this leads me to more questions..

How can i calibrate the back focus with a Film Lense????
How should i measure the right Back Focus (52.000mm)???

Film Lenses (Primes and Zooms) have to be calibrated exactly on a Kollimator first.....So I also have to get sure for the right back focus of the Camera.....

With Primes, I can compensate this with new scales, But a Zoom Lens doesn`t work with a wrong back focus.......

Anybody got an idea about.......?????

Sorry for my bad english, but I hope you know, what I will say.....

Greets

Steff

P.S.: Nice sound from the PL Mount (Quiiiiiieeeeckkkkkkkk)????

[Andreas Höhn]

1. there is a FOCUS HOOK SET available in the red store. this should fix no.1
http://www.red.com/image/path/87/804011.jpg

[Cüneyt Kaya]

same here
http://www.projectred.net/

"...Coming from an HD background you would immediately think to check the back focus. But the RED has no back focus..."

[Emanuel A.]

It seems there's something related here:

http://www.reduser.net/forum/showthread.php?t=3650

Here you can follow up the issue still better:

http://www.reduser.net/forum/showpost.php?p=67324&postcount=5

[redapple]

Thx for answer,

@Berlin, thats not right,

- Each Camera needs a Back Focus, at HD Lenses it`s variabel, cause
the sensors of the cameras are not allways exactly at the same position.

- A Film Camera has a Fixed back Focus of 52,000 mm the tolerance here
is +/- 0,010mm. When a Film Camera (like 435 or else) get`s
different temperatures or something, you have to refix it to get little
slides in........

- If red want`s to use Film Lenses on their camera, they need a option
to bring the distance between PL and sensor to exactly 52,000 or you don`t will be happy by using film lenses like Master Primes or Zooms...

thx

[Cüneyt Kaya]

sorry for confusing.

you are absolutly right...red has no variable backfocus. it is fixed at 52
better: should be fixed.

[redapple]

yeah, and you need a option to get slices in or out of the PL Mount, but you allways need a Measure Instrument (like a Kollimator) for the camera to bring it on exactly 52.000.....

I talk to the guys from Red at the IBC, they all come from the film industry, so I´m sure, they know that problem and work around to fix it.......

[Frank Mirbach]

think so too, remember: It´s still Beta...

[redapple]

Of course, but this is the best stadium to talk about such Problems, better than the camera is finished and then..........:-)
So don`t missunderstand me, I´m a absolutly fan of the camera and yesterday i`m very proud to be (maybe one of the first), who push the red button in germany....:-)

[Cüneyt Kaya]

better to talk about things now and get fixed before delivery...because there is no red service station in europe yet

[redapple]

yes, that`s right............

[Matt Uhry]

think so too, remember: It´s still Beta...

The PL mount was not just invented. It's been 52.00mm for many years.

It is an easy fix.

Matt Uhry
www.mattuhry.com

[martinnoweck]

... and yesterday i`m very proud to be (maybe one of the first), who push the red button in germany....:-)

congrats and envy ;-)

martin

[redapple]

The PL mount was not just invented. It's been 52.00mm for years.

It is an easy fix.

Matt Uhry
www.mattuhry.com



Think so too, matt.......
But the question is, how can i collimate the camera to the right measure?
It`s not done, if Red fix it on 52,00! On a professional camera test, you need to calibrate the lenses and as well the camera on a collimator. You have to be sure, that the measure scales on the lenses are right, also the camera is on 52.00. if not,you have to bring it to. It`s an optical law.............
Tip: Ask you local Focus Puller :-))

A Camera is never "fixed" on 52.00... Temperatures, Hits etc. will change it..


P.s. thx martin

[laguun]

congrats and envy ;-)

martin

we´ll start working on the shots next week and will be putting them through several online/DI pipelines.

[Matt Uhry]

Think so too, matt.......
But the question is, how can i collimate the camera to the right measure?
It`s not done, if Red fix it on 52,00! On a professional camera test, you need to calibrate the lenses and as well the camera on a collimator. You have to be sure, that the measure scales on the lenses are right, also the camera is on 52.00. if not,you have to bring it to. It`s an optical law.............
Tip: Ask you local Focus Puller :-))

A Camera is never "fixed" on 52.00... Temperatures, Hits etc. will change it..


P.s. thx martin


Here's how you can collimate the RED.

You can't use a depth gage ! So you will have to do it optically.

Best thing to do is go to a lens tech and let him or her do it. They have specialized tools and experience. If there is none in your area or it's midnight in a hotel room in Siberia and you just want the camera to focus on scale like it should here's what you can do:

Take your widest / fastest / best lens that you trust the markings on. 18mm T1.3 would be a good place to start.

Put the lens on the Red and focus on a focus chart, do it a couple of times to make sure you get it right.

If the lens is focusing too long - showing 20 feet on scale when focused at a 6ft target you need to remove some shims from the mount to back it up. It you are focusing too short you need to add some shims. You can preview adding the shims by loosening the mount a little and pulling the lens slightly forward, while focused at the correct scale distance.

Repeat procedure until it works. Test at different distances and infinity. Test your other lenses zooms etc. The zooms should hold focus when zoomed. If you set the camera to a lens that's not correct it won't work with your other lenses.

Matt Uhry
www.mattuhry.com

[redapple]

Are the shims ordinary PL Shims?? And are allready some in, when Red deliveres the Cam???
I often do calibrations on Film Cameras and Lenses, so It`s no Problem for me....
I also see, that the screws on the PL-Mount of the Red are not good, they will crashed, if you open and close it often, better to change against High Quality slotted screws

But very very much thanx for your help matt!!!!

[Stephen Williams]

remember: It´s still Beta...

Hi,

Are you sure?

Stephen

[Stephen Williams]

Hi,

You don't need to guess the error it's easy to calculate


Using the formula (d = f squared divided by a-f ) will give you the distance the lens is out of the mount when the lens is focused at infinity. d = displacement of lens out of mount at infinity. f = focal length of lens. a = distance of sharp focused object. You can use inches or metric measures. Note, d = 0 when a = infinity. Example: for a 50 mm lens (2 inch) set to infinity but is focusing at 10 feet. 2" squared/ 10x12"-2 =4/120"-2"=4/118"=.034" so the lens mount is .034" too far out of the mount. Shorten the mount by .034". Better yet, try .030 and check again.

Stephen

[Frank Mirbach]

Hi Stephen,

well, I consider a camera without working viewfinder and without soundrecording still a beta. I might be wrong, but Jim Jannard said so somewhere here, too. I think we all have to give the Red team some time to work on all the issues and solve the problems one after the other. I don´t believe they will let their customers down by delivering "off focus" cams and lenses. Besides, they couldn´t afford so. All the other manufactures would jump on that opportunity to talk bad about Red in terms of quality. And as far as I know, this focus problem was only the case with some cams, not all.

Regarding all that, there might be even some positive aspects in getting the Red not earlier than May ;)

[Matt Uhry]

Hi,

You don't need to guess the error it's easy to calculate


Using the formula (d = f squared divided by a-f ) will give you the distance the lens is out of the mount when the lens is focused at infinity. d = displacement of lens out of mount at infinity. f = focal length of lens. a = distance of sharp focused object. You can use inches or metric measures. Note, d = 0 when a = infinity. Example: for a 50 mm lens (2 inch) set to infinity but is focusing at 10 feet. 2" squared/ 10x12"-2 =4/120"-2"=4/118"=.034" so the lens mount is .034" too far out of the mount. Shorten the mount by .034". Better yet, try .030 and check again.

Stephen

Thanks Stephen, bad Math Skills, California Schools in the 70's I blame Ronald Reagan !

Would this formula only work with a prime lens of simple single optical block design? Not a zoom or not a retrofocus or close focus compensating design ?

Matt Uhry
www.mattuhry.com

[Stephen Williams]

Hi Matt,

I think it would work with any prime lens, however if infinity is focusing in the close focus region the mount is going to be way out, so you will probably have to re test. LOL!

Zooms are more complicated as the will only be perfectly focused at the beginning, end and somewhere else due to the s curve that focus on a zoom covers. When a zoom is out there could be rather more things wrong than just FFD.

Stephen

Stephen

[redapple]

Thats all great guys, thanx a lot..........

[chuck colburn]

Hi Matt,

I think it would work with any prime lens, however if infinity is focusing in the close focus region the mount is going to be way out, so you will probably have to re test. LOL!

Zooms are more complicated as the will only be perfectly focused at the beginning, end and somewhere else due to the s curve that focus on a zoom covers. When a zoom is out there could be rather more things wrong than just FFD.

Stephen

Stephen

What Stephen said.

[redapple]

All in all, great forum, guys.......
Another question : What is the latest software version ? And what features will work on it?
My Version just make 4K red raw and 24/25/29,97 frames, no dual link output and just 1HD Sdi Output in 720/60P (confusing, by a frame rate of 25??)...

Greets from munich city

s

[Cüneyt Kaya]

2k cropped 72 fps


http://www.reduser.net/forum/showthread.php?t=4974

monitoring: ?
audio: No

2k scaled will be avaiable soon

[redapple]

And when you shoot with 72fps, how can you bring it to 25??
With compressor, or is there any other software......?

[Stephen Williams]

And when you shoot with 72fps, how can you bring it to 25??
With compressor, or is there any other software......?

Hi,

It's just slow motion, the shot lasts longer.

Stephen

[Rob Lohman]

Yes, you set a project resolution (basically what you want to playback / edit at), and then you enable variable framerate to record at a different framerate from the project framerate.

Since you're in Europe you probably want the project set to 25 fps. Then you can set the variable framerate to as low as 1 fps or as high as 25 fps (4K) or 80 fps (2K) [limits at this point in time].