OVF via beamsplitter glass

[Peter Osinski]

I know that red had discussed a 20k usd ovf solution for epic in the past that got put on the shelf, but in theory how hard would it be to add a fixed ovf like what you had on old bolex reflex cameras by adding beamsplitter glass in front of the sensor?

That way you could still have video preview during shooting that would be uninterrupted and you would save on the engineering costs involved with a spinning mirror.

What type of light loss would you see with this type of rig?

 

[Evin Grant]

1 stop for most beamsplitters, you may be able to get away with a 60/40. Either way the engeneering and optical challenges are not worth the cost.

 

[Peter Osinski]

My thoughts were to use this idea with a custom designed machine vision camera. If i'm already paying for development of a specialized camera do you think it would be worth it?

 

[Robert Hart]

It appears that unless there is engineered, a revised optically lengthened mount to enable the workspace for an optical splitter, the deep setting of the sensor within the casework may have designed the option of an optical split out of the EPIC/SCARLETT camera family.

If the front structure is itself not a replaceable module in the design which would enable an optical split to be substituted, then that probably won't be happening. Debate elswhere in this forum seems to vote against an optical viewfinder being more than a legacy comfort for operators formerly trained on film cameras. Improved electronic viewfinders are predicted to save the day. For the meantime, there may remain a dark age for a year or two yet.

The longstanding traditional methods of maintaining sharp focus upon subject which preceded reflex viewfinders remain perfectly valid, if a bit time-consuming.

Related to the 2K realm, there were C-Mount zoom lenses for non-reflex cameras which had an optical split and viewfinder eyepiece integrated. Three such to my vague recall were the Angenieux 12 - 120, 9.5 - 57 and Pan Cinor Som Berthiot 17 - 85. None likely work for Super16mm sized sensors without vignetting somewhere through the zoom range.

The deep setting of the EPIC/SCARLETT sensor will rule these out as well. A Red One with a custom front mount might be able to accommodate these lenses. In the real world, there would be no benefit except for being able to say I did it.

On the P+S version of the SI2K, the Angenieux reflex lenses as fitted to the early CP16, might work only with the entire IMS-Mount removed and the 4x screw C-Mount disk substituted. The viewfinder split path enclosure impinges upon the IMS-mount rim.