2k, 240fps, canon glass....really soft images

[Ian Planchon]

Andy, very astute, that was my nightmare on the shoot you speak about, and as much as you'd like to think it's everything but BF, it was BF.....and it sucks. It came from going from Canon to PL.....I have since bought a Red Focus but that's just a stop gap. I really wish there was something better and affordable. The Denz is 4500.00 plus another 4500.00 for the rig that checks the collimator. A real weak link in the whole changing mount game.

so there is no other way to adjust BF without that red focus?

 

[Andy White]

You can do it if you have a known wide angle that's good on other cameras. If you use a lens that's already out, you'll risk BF that'll be good only for that lens.

There are quite a few threads that might be worth looking through... RU search is a bit rubbish, so this is better site:reduser.net backfocus (paste into google).

 

[steve green]

so there is no other way to adjust BF without that red focus?

The other much more expensive option is call Denz FDC http://www.reduser.net/forum/showthread.php?33034- It works beautifully, the BF is either in or out, not guessing! Problem is the whole rig to really do it right is 9000.00 for the two components.

 

[Jacek Zakowicz]

The other much more expensive option is call Denz FDC http://www.reduser.net/forum/showthread.php?33034- It works beautifully, the BF is either in or out, not guessing! Problem is the whole rig to really do it right is 9000.00 for the two components.

I don't know about the not guessing part :
There are different offsets depending on the camera OLFP
I know for Epic it's about .003". for Alexa, Sony, its all different.

 

[Dan Kanes]

Not trying to be a hater here...

because like everyone else, I'm on a budget...

I actually tried the same CAVISION filters you are talking about...

THEY ARE 100% ABSOLUTE SHITE.

I'm pretty sure that may be part of your culprit.

If you can, also try shooting at the highest quality redcode that you can get away with - I didn't notice if anyone else mentioned that.

If you can get your hands on a Tiffen Water white ND (or IRND) or some other brand - the best option of course is the rear filters for long lenses - but of course not always accessible.

If you want to see what the ND is doing - try setting up a controlled shoot in your house or prep bay and pick a medium distance subject with the same lens, put the ND in front and then take it away and see if it has an effect.

also - if the lens is unsupported check to make sure it is not drooping from the weight - causeing a non-flat focal plane.

 

[Andrew Allsbury]

I found those filters to work pretty well considering the cost in some cases, but I also found it useless on our 80-200 tokina. The lens and nd combo exhibited a weird smear effect.

 

[Ian Planchon]

I found those filters to work pretty well considering the cost in some cases, but I also found it useless on our 80-200 tokina. The lens and nd combo exhibited a weird smear effect.

similar to me. the filter has worked really well for the rest of the kit, 17-50, 35, 50 and 85mm lenses, but it was definitely the culprit in this case. went out today and re-shot without the filter and everything is crystal clear. at least its not the back focus!