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  • Hey all, just changed over the backend after 15 years I figured time to give it a bit of an update, its probably gonna be a bit weird for most of you and i am sure there is a few bugs to work out but it should kinda work the same as before... hopefully :)

RED One and Master Primes issues

Sanjin

You're great, you never fail to deliver!

Perfect....lol
 
Why NULL and DENZ?

Why NULL and DENZ?

Am I missing something here?

Simple question: Why would anyone need NULL or DENZ or any specialised device to collimate the camera's FFD?

I always thought that first and foremost it was the lens that needs to have the correct FFD. Once all lenses are collimated, you set the camera's FFD to the lens, not to the NULL. What is the point setting camera's FFD to the NULL when we film with a lens, not with the NULL?

One can use the NULL to check the FFD on the camera, although the usefullenss of this check is questionable. That's OK. But, I don't think one should set the FFD of the camera to anything else except the taking lens! All is needed is your eyes...maybe spectacles too :001_cool:
 
Pawel Achtel said:
Am I missing something here?

Simple question: Why would anyone need NULL or DENZ or any specialised device to collimate the camera's FFD?

I always thought that first and foremost it was the lens that needs to have the correct FFD. Once all lenses are collimated, you set the camera's FFD to the lens, not to the NULL. What is the point setting camera's FFD to the NULL when we film with a lens, not with the NULL?

One can use the NULL to check the FFD on the camera, although the usefullenss of this check is questionable. That's OK. But, I don't think one should set the FFD of the camera to anything else except the taking lens! All is needed is your eyes...maybe spectacles too :001_cool:
Click to expand...

Pawel,

you are definitely wrong here.

Your PL RED mount (can be also any other cine PL camera) can be "precise" collimated only with the instruments like a Denz FDC, Optitek Optimator, RED Null or similar,...

If something is wrong then you can address that to the lens.

And lens can be collimated on a projector using other instruments only by the special lens service or in the case of Arri/Master primes at Carl Zeiss AG factory in Oberkochen, Germany.

In the case of your MPs in Australia there is no way to "false" lens collimation at ARRI Australia because they have to sent them in Germany.

Also because of MP's Carl Zeiss AG patented aspherical floating elements that can be "moved" during use,... and so on...

Hope this helps.
 
Pawel Achtel said:
You make me laugh, Sanjin. :ihih:
Click to expand...

Pawel,

you are not so serious as you always want and pretend to be.

And you should ask and call experts that can help you somehow.

Also I'm falling from my chair just because of... :rofl:
 
Pawel Achtel said:
Am I missing something here?

Simple question: Why would anyone need NULL or DENZ or any specialised device to collimate the camera's FFD?

I always thought that first and foremost it was the lens that needs to have the correct FFD. Once all lenses are collimated, you set the camera's FFD to the lens, not to the NULL. What is the point setting camera's FFD to the NULL when we film with a lens, not with the NULL?

One can use the NULL to check the FFD on the camera, although the usefullenss of this check is questionable. That's OK. But, I don't think one should set the FFD of the camera to anything else except the taking lens! All is needed is your eyes...maybe spectacles too :001_cool:
Click to expand...

In part i agree, it's nice when lenses are collimated for the camera. But quite often i rely on lenses being correctly collimated across a set, if that is so then i would be happy to adjust my FFD to infintity of a lens ( within reason ) that is correctly setup. However if i am adjusting my FFD to a set of glass without correct collimation across the set it could be that i spend a lot of time adjusting my FFD to suite lenses, and would send that glass back to my tech or hire house with the message, please collimate this glass correctly setup for a camera with a PL mount FFD, knowing that my camera is on the button with its FFD set correctly, hence the RED NULL.

When i send my Moviecam or Aaton in for service i want it to come back shimmed to a correct FFD, in the case of PL 52MM give or take a few thousands of an inch.

It's horse for coarses, but i know i like to have the security of knowing i can collimate my FFD within 5 microns, on set, if think for some reason it may have shifted.
 
One more thing is that a precise collimation instrument always necessery in any camera world.

sharpmax.jpg

Sharp Max from Carl Zeiss

image_539.jpg

Sharp Max from Carl Zeiss

Right example for a precise collimation of any HD digital camera is the instrument called "Sharp Max" from Carl Zeiss:

"An exactly adjustment of the Back - Focus is necessary for all film and photo lenses in order to use the
full optical performance. At lenses for HD - digital cameras, like the Carl Zeiss DigiPrime lenses, the
Back - Focus must be adjusted at the lens. Therefore a precisely, simple and quick procedure is required.

Sharp Max is designed especially for that task. The athermal design ensures a stable 8 - position of
the installed Siemens - star over a wide temperature range. Illumination and power supply are integrated
in the device. This permits a self sufficient use without any additional means. With the lens flange the
device can be fixed easily at the lens under test.

The Siemens- Star comes with a high number of sectors resulting in high spatial frequencies in the center
of the image of the camera viewfinder. This enables a precise and reproduceable adjustment of the
Back - Focus. A long operation time of the battery is realised by an auto switch - off function of the
illumination.

A sturdy design, easy operation and high accuracy are the hallmarks of this unit. For these reasons,
Sharp Max is particularly suitable for use by service staff and in the field during film productions."

LINK>>>
 
If lenses are correctly collimated then yes, you don't need a Denz or a Null. BUT you only know that if you actually have a collimator and make sure that you're lenses are. Robert is also right with the fact that you also need to rely on you're set being perfectly collimated all through. With a Denz or a Null you will know that your camera is set, so you can detect if the lens is off. There's a reason why 1st AC's prep their gear the day before. One of the reasons being that they know that what the lenses respond as on the day of the shoot. If they're a few lines off or not. That can only be checked with a perfectly collimated camera.

So you don't need the gear but it sure as hell makes life easier.
 
How many of these devises can tell you if the mount is parallel to the sensor?
With heavy zooms being used, I would not be surprised to see such errors.

Stephen
 
Stephen Williams said:
How many of these devises can tell you if the mount is parallel to the sensor?
With heavy zooms being used, I would not be surprised to see such errors.

Stephen
Click to expand...

According to Optitek Optimator:

"Optitek Optimator is a high precision instrument that, regardless of environmental conditions

assures precise sensor location (camera back focus, sensor flange depth) checking and adjustment.

The Purpose of This Instrument

— Check the Flange depth of the sensor
— The max resolved number can be recorded(written down) for future reference
— Generate reference frame
— Check camera real resolution
— Check camera light sensitivity
— Make all tests identical, “laboratory condition” compliant regardless of location
— Communicate sensor issues remotely by emailing reference frame grabs
— Create sensor test standards that all digital cameras can be tested to"

LINK>>>also watch the presentation movie>>>

Also Denz FDC works with two (probably laser) "traces" to get an optimal measurement of the PL FFD standard (52mm)

and if both are not at exactly to the same distance then your mount or even sensor is out of axis.
 
Optimator's features

Optimator's features

Stephen Williams said:
How many of these devises can tell you if the mount is parallel to the sensor?
With heavy zooms being used, I would not be surprised to see such errors.

Stephen
Click to expand...
AFAIK Optimator is currently the only tool that will show AND quantify sensor tilt(how parallel the mount and sensor are) centering(if the sensor center matches the mount center), and give you a reference number for "in focus" resolution on a digital camera- be it RED, F35, Arri D21, Genesis, Canon 5D2, Nikon D90 etc. etc.
It also tells you What the errors are(how much tilt, how far off center etc..)
Not to mention "special" features like color matching cameras and lenses, white balance calibration etc. etc..
 
OptiTek said:
AFAIK Optimator is currently the only tool that will show AND quantify sensor tilt(how parallel the mount and sensor are) centering(if the sensor center matches the mount center), and give you a reference number for "in focus" resolution on a digital camera- be it RED, F35, Arri D21, Genesis Canon 5D2, Nikon D90 etc. etc.
It also tells you What the errors are(how much tilt, how far off center etc..)
Not to mention "special" features like color matching cameras and lenses, white balance calibration etc. etc..
Click to expand...

That's GREAT but are you actually shipping?
 
Sharp Max

Sharp Max

Sanjin,

Sharp Max is for B4 mount. With B4 mount you adjust the lens to the camera's FFD. In PL you adjust the camera's mount to the lens' FFD.

Therefore Sharp Max makes sense. The NULL and Denz don't.
 
Pawel Achtel said:
Sanjin,

Sharp Max is for B4 mount. With B4 mount you adjust the lens to the camera's FFD. In PL you adjust the camera's mount to the lens' FFD.

Therefore Sharp Max makes sense. The NULL and Denz don't.
Click to expand...

Pawel,

just in case that your "beloved" lens is out of FFD

(that you don't see it in the case that you are somehow "flashed" and over-blinded with love for a certain lens, its sharpness, speed, rendering, bokeh, contrast, etc...)

then you can "blame" the camera mount for all your faults.


My story is very simple and fulfilled with very exact and logical sense.

The FFD adjustment has to be done on both sides (almost simultaneously) and it is about the two sides, mount and lens.

But not just on one side and there are many reasons for that.


Also there are many ways to do back-focus but also can be done with some of the mentioned FFD instruments

that can check FFD on both sides at the best and the most precise way.

The lens mount and particular lens can be adjusted to the maximum precision of FFD (PL 52mm)

and then you can expect that your "beloved" lens can do extraordinary performance at your camera system and in this example on RED1.

Unfortunately for some of the high end and the best cine lenses is the case that can be only very precisely factory collimated.
 
Sanjin,

You didn't understand my post. There is no point adjusting your camera's FFD to correct value (the NULL) regardless whether:

1. Your lens is correctly collimated (52.000 mm)
2. Your lens is incorrectly collimated (not 52.000 mm)

You always collimate the camera to the lens because IF the lenses' FFD is incorrect, you will still make sharp pictures and the focusing scales will match. If you collimate the camera's FFD with the NULL, the scales on such lens will be out!

The SharpMax works the other way around beacuse it uses B4 mount, so it makes it much more useful than a similar device for a PL mount.
 
Pawel Achtel said:
Therefore Sharp Max makes sense. The NULL and Denz don't.
Click to expand...

So Pawel. Here's a scenario. You own several sets of lenses. You put one of them on. It's off. Now is it the lens or the camera? You adjust the camera to it, just to find that the next lens is off. Now you have to adjust to that lens. Then the next lens is off.

Now which lens is correctly collimated?

Sure if you own one lens it's maybe useless, but otherwise?

I've used my MP 14mm as a "null" lens since I knew my MP's were collimated and they were that recently and therefor still are, but other lenses has been off several times and sometimes it's been the camera and it's been an annoying guessing game.
 
Fredrik Callinggard said:
So Pawel. Here's a scenario...
Click to expand...


Fredrik, Yes, using the NULL you can CHECK if the FFD on your mount is correct. You DON'T use the NULL to set the FFD. It is a verification tool, not an adjustment tool. That's all I tried to say.
 
Pawel Achtel said:
Fredrik, Yes, using the NULL you can CHECK if the FFD on your mount is correct. You DON'T use the NULL to set the FFD. It is a verification tool, not an adjustment tool. That's all I tried to say.
Click to expand...

ahh ok, sorry, was just skimming the posts
 
Pawel Achtel said:
Sanjin,

You didn't understand my post. There is no point adjusting your camera's FFD to correct value (the NULL) regardless whether:

1. Your lens is correctly collimated (52.000 mm)
2. Your lens is incorrectly collimated (not 52.000 mm)

You always collimate the camera to the lens because IF the lenses' FFD is incorrect, you will still make sharp pictures and the focusing scales will match. If you collimate the camera's FFD with the NULL, the scales on such lens will be out!

The SharpMax works the other way around beacuse it uses B4 mount, so it makes it much more useful than a similar device for a PL mount.
Click to expand...

And if you have a set of lenses which all have varying values of collimation? would you be happy with that?
Happy to keep adjusting your FFD?
Where is the benchmark for your cameras FFD?
It's a bit of an agricultural way of looking at this.
Are you saying that the couple of hundred of us who have purchased the RED NULL don't know what we are doing and have purchased it needlessly?
Should i shim my moviecam PL mount to fit all the lenses i use on a daily basis, and carry around with me a handy pack of shims and all my collimation kit ready to adjust it to any old lens?
Or just make sure all my lenses are collimated to a standard that will be usable on my PL mount camera, which by the way has a perfectly collimated mount of 52mm.
Shim the lenses, before they come on a job, collimate them correctly. Within certain tolerances.
If it was the case that we allways adjusted the camera to the lens, what would be the point of setting the back space during a service anyway?

Now if you're a DP and you have a nice Arri ST that you take out regularly with a set of glass, and all that glass can be collimated to exact tolerances across the set, yes sure, adjust the camera mount, make that setup work, i mean we don't want o get into the scenario of re-setting witness marks.

These FFD collimation tools are engineered for a reason. There is give and take both ways.
 
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