Mark Virtue

Are you guys testing this by focussing at the further extent of zoom, then zooming back to wide angle, then back out again?

 

If you first focus at wide angle and zoom, the accuracy won't be enough.

 

Probably obvious but just thought I'd throw this in there.

I did my testing going both ways, using live view punched in to 10x.

The Canon  24-70(gen1), 16-35(gen1), 8-15 are not parfocal. The 70-200IS(gen1) is and I'd have to presume the latest is as well.

Could be totally unrelated but I'd never read that before, that sensor alignment wasn't specific to a model but the individual camera.

 

Compact view cameras allow for shimming of their digital back to achieve the optimum sensor position. In massive produced DSLRs the tolerances are close enough and can be masked by micro-adjust. But I have seen cases on friends equipment where one end of the sensor was off by a fraction and he could never get anything in focus on that side. The camera went back to service and the service report read -- "shimmed sensor".

Thanks! Just means I get to go out and pickup some more new old glass :)

How do people deal with lenses that have a rotating front element? Is there anything that can be done, or do you just avoid them like the plague?

 

HD-SDI passes the genlock, assuming I am reading web pages properly.

How about an LCD shutter in front of the lens? I'd run across a web page of a company that builds them and has the sync box for it. The price was not cheap, around 2K USD.

EDIT:
Found the link http://tessive.com/

Found one reference on reduser: http://www.reduser.net/forum/archive/index.php/t-28247.html

That looks like the sensor well overflowed. I'm trying to find links to documents that actually describe the phenomena and am failing right now. It's more common with CCD sensors if my memory serves me correctly. The normal fix is in firmware to cap the value and not flip the bit to a negative number.

Odd first post here:

OS X is based on the CMU Mach Kernel. It predates Linux. And was used as the under pinnings of the NeXT computer, prior to Steve Jobs bringing those ideas back to Apple on his return.

So back on topic. I don't think that the BMCC will kill DSLRs for video. But I have to say that for what I want, it is nearly the perfect tool. SSD prices are coming down, and are cheaper than large name brand UHS-1 SD cards, so storage really is a non issue. I do 3+TB of still photos a year. Managing large disk arrays is part and parcel of what I do there, so adding a few more TBs is not going to kill me. It will also get archived and off-lined faster than the stills, which I need to keep 100% accessible for 2 years.