Potential 2K OLPF for the FS700

C

Colinelves

Well-known member
Hello all,

I stumbled across this company while scouring Gumtree for bargain lenses: http://www.mosaicengineering.com - as someone was selling one of their anti-aliasing video filters for a 7D. Basically they make custom OLPF filters as well as anti-aliasing filters for a bunch of different Canon and Nikon stills cameras.

Given this track record they seem like the best company to approach to develop a 2K OLPF for the FS700 to kill the aliasing in super-slow-mo & 2K Raw.

I've emailed them already to ask about the possibility, but it might be worth a couple more of you getting in contact to make them aware that there is some demand!

Cheers,

Colin

EDIT: I also checked the price of the Sony 2K filter for the F5, $800! All their filters are around $300, so if they can do one for the FS700 for the same price, I'll be happy!
 
Last edited:
Where would you place the filter though? There is no access to the sensor unless you remove the nd-filters and protective glass. :-\
 
OLPF's that sit in front are designed for a single focal length. That's fine for primes, but, somewhat inconvenient for zoom lenses.
 
cuervo said:
OLPF's that sit in front are designed for a single focal length. That's fine for primes, but, somewhat inconvenient for zoom lenses.
Click to expand...

He means they'd sit in front of the protective glass, not in front of the lens.

The 2K OLPF made for the F5 sits in the same position - i.e. it is the protective glass on the F5. The only issues I can see are: a) how to fix the OLPF in place (which is an engineering problem I'm assuming they can solve) and b) will there be a problem stacking two OLPFs on top of each other - which I hope is no.
 
b) will there be a problem stacking two OLPFs on top of each other - which I hope is no.

An OLPF, functionally, is somewhat like a polarizer. Which means stacking them presupposes that they're aligned with each other in the proper orientation.
 
I just e-mailed them. Can't hurt.

Seems like there's enough space between the FS700 and the rear lens element to fit an OLPF in.
 
hmmmm....seems pretty shaky to be mucking about on top of the sensor. Sandwiching something on top of the existing sensor will surely create diffraction effects at the interface, short of glueing an OLPF on, then you're facing index of refraction issues. This is much too complicated for anyone to seriously consider.
 
cuervo said:
hmmmm....seems pretty shaky to be mucking about on top of the sensor. Sandwiching something on top of the existing sensor will surely create diffraction effects at the interface, short of glueing an OLPF on, then you're facing index of refraction issues. This is much too complicated for anyone to seriously consider.
Click to expand...

I'm not sure why this would cause more problems than rear mounted filters. Regardless, given that the company's main line of business is designing and building custom camera systems, I suspect they have more knowledge and experience to bring to the table than you or I. If they say it can't be done, then fine. If they say it can, i'm minded to believe them over you.q
 
FWIW, I am retired from 35 years in the opto-mechanical design business. Compromises in design are always compromises in performance. Nothing is free in this optical world. But, I can understand your doubt. In the end, it would be cheaper to sell your FS700 and buy an F5. Best of luck, Colin.
 
Last edited:
I guess this is for HFR uses? As the 4K downsample would yield perfect results at normal speeds

Wasn't there a whole range of these filters when the first days of dSLRs appeared? Caprock and so on. I'd have thought ebay would be littered with them?

From what i know about such things i think they effect of the blurring would need to be quite heavy to get rid of the anti aliasing. Also in our case isn't the AA a result of debayer issues with not reading the full sensor rather than issues of absolute detail? So they may not work in quite the same way as they would if the optical path was straight to a full sensor. What i mean by that is that a low resolution sensor would still have pixels that were edge to edge whereas skipping misses out actual lines. Binning might be a lot better though but there's no real info on how Sony are binning the 2K sensor but the degree of blur needed might be quite high.

I should finally get a chance to go through the O7 properly in the next few days. One area i'd like to look at is edges at HFR compared to normal, because i think that there's a lot of compression going on which no filter would be able to sort out. Just a hunch based on a few things i've seen (and the seeming impossibility of squeezing 2K 240fps down a small cable)

The irony of HFR is that everyone gets to see fine detail as it's all slomo!

Hope everyone had a good break
cheers
Paul
 
You must log in or register to reply here.
Back
Top