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08-15-2009, 12:03 PM
I have noticed a lot of products for setting your back focus to the ?micron, but as I recall back focus adjustment was set for the lenses. Has that changed? I remember a year ago that people were setting the back focus specifically for different lenses, yet now things like the Red null and others make it sound like one size fits all. What have people found? Since I don't own one of these I always check back focus with the widest lens in a set on any new project.
08-15-2009, 08:20 PM
I guess nobody remembers those days.
08-15-2009, 08:40 PM
Red Null is for calibrating the camera. You also need to make sure each lens is properly calibrated.
Dusty
08-16-2009, 09:04 AM
You can still adjust the camera to each lens, if you use widest lens to set the camera, you have the best chance of success. But you cannot be sure about the settings if your lenses are not checked and verified on collimator for proper back focus adjustment. Checking and changing back focus (actually it's the Flange Depth on camera) for each lens on set is not very accurate or practical, depending on your style or genre.Originally Posted by Michael Epple
With the Optimator you can adjust the camera Flange Depth and knowing that that's correct check and adjust your lenses accordingly. If you are careful and with some practice it should not be a major hurdle. The checking part that is. The adjustments to lenses should be done by a qualified tech unless you are confident that you can handle the job of removing lens mount and shimming lenses, which requires whole new set of skills. All that should be done during the first prep of a camera/lens setup and shouldn'change for the duration of job if lenses and camera are not bumped, dropped etc. Then you would just do a quick Flange check on camera between setups to be sure.
Jim mentioned a while back that there will be a "lens test mode" on the RedOne for that purpose as well. That would certainly help to put things in place. I hope this helps to explain the procedures....
08-16-2009, 09:33 AM
Do you mean Epic?
08-16-2009, 11:03 AM
It sounded like a firmware/software feature so it was a possibility on REdOne.
All necessary hardware is there already. If anything it's easier to implement on RedOne because of the FPGA flexibility. Once they go ASIC they lose the flexibility, or at least some of it. Some core features just have to be baked in...
08-16-2009, 11:08 AM
As I recall, people found differences between lens sets on their red, even though the lenses were properly collimated. I don't know if it is because of something else, or the IR + OLPF filters. Maybe I'm wrong. I'm just asking. When I rent a lens set, I've just prepped the camera like a normal 35mm package and use an HD monitor and charts. I always reset the flange depth right away, unless the same set was used last time and all the lenses match the tape. I would love the Optimator, Red Null and other products to be the quickest, easiest check.
08-16-2009, 11:38 AM
The only setup issues that I'm aware off is with some Master Primes, 27mm and 40mm. But that's not a common setup- the MPs are very pricy. And also a bit of controversy as Pavel puts his life on the line for MPs.
Don't forget that aside of cleaning optics back focus issues are by far the biggest task of rental house lens techs. They shim lenses all the time to match ACs requirements. And this is in traditional film production. REdOne is a very high resolution camera so it may even be more critical than film cameras..
What I'm saying is that rumors that lenses are off on RedOne can't be taken at face value and need more testing and verification. But who has the time...
08-16-2009, 06:53 PM
Interesting, I think I missed that one. What would the lens test consist of?
08-16-2009, 10:37 PM
I don't even know if it's still on the list, things changing and all. I know what I would put there but I don't work for Red.
I am planning a software module for the Optimator system but that would test sensor and DSP not lenses.
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