7D Junk Pruned
Like cutting away deadwood, a new DSLR kit prunes the useless junk off the Canon 7D.
By cutting out what you don’t need it opens the camera up for cine lenses, knocking over another grumble about using this type of camera on serious production.
The mirror assembly and optical viewfinder goes. A DSLR mirror is a fine thing but it can’t handle 25 frames per second or more needed for video. It tucks up out of the way making the camera’s optical viewfinder redundant, forcing the operator to use the LCD screen, a situation referred to by Canon as shooting in live view mode. (Still to be solved is the problem that the LCD screen blanks out when you plug in a monitor.)
Once you get rid of that whole gubbins, there is room for a cine lens to snuggle up to the sensor – which is what the wider angle lenses like to do in the film and digital film camera world.
What’s more there is room for a shroud to stop spill light flying around inside the camera cavity and creating stray flares – something longer lenses like to do if you let them.
But to fit the cine lenses to the camera you need a new lens mount because the flange focal depth (distance from lens flange to sensor) of a movie camera is greater than DSLRs.
7D PL Lens Mount
You don’t have to do all this yourself – you now find a Canon 7D with all these modifications built in. The 7D EVO PL54 is a Canon 7D converted by the German film accessory company Denz. Auckland camera rental house Metro Film recently took delivery of two units.
The converted 7D EVO PL54 accepts PL mount cine lenses, and sits on a rod system that allows the Arri and other common film type accessories to be used on the camera. Big zooms fit the camera too – or rather the camera perches on the end of them.
The optical viewfinder is binned and an Arri accessory 4 pin RS socket for an Arri remote switch takes its place.
With still lenses gone focus pulling is suddenly a precise game again.
Cine lenses have advantages. They are tend to have a consistently matched look across a set of primes, they are designed to avoid image shifts during a zoom or focus pull, and are faster than many still lenses. Zoom lenses are designed to track accurately during zooms and hold steady apertures over the zoom range.
All this means cine lenses come at a price which far out weights the camera itself. It propels the converted Canon 7D to the next level in usefulness, but also in cost.
7D Evo PL54 rig with film lens and accessories
Andy Roelants, founder and managing director of Metro Film says the conversion of DLSR to PL is a response to the needs of cinematographers.
He says the kit is a low cost presentation of new technology for the commercial industry.
“They need to use good glass.”
But what about the other DSLR hot topic – the Canon 5D?
The Canon 5D sensor is bigger than a 7D. In DLSR terms it is a ‘full frame’ sensor. At 36mm x 24mm it is equivalent to a 35mm still frame.
The Canon 7D sensor measures only 22.3mm x 14.9mm which is just a little under the dimensions of a 16 x 9 (1:1.78) 35mm motion picture frame of 24mm x 13.5mm.
This means cine lenses cover the Canon 7D sensor without trouble but the same lenses will seriously vignette if they were fitted to a Canon 5D – a pity perhaps, but that combination just isn’t going to work.
Aw, this was a really quality post. In theory I’d like to write like this too – taking time and real effort to make a good article… but what can I say… I procrastinate alot and never seem to get something done.