FORBES70 - critique please

[Nikkor]

Otherwise, what a look. the depth of field rendering, not just the amount but the look of the roll-off/in, coupled with the extremely high resolution 1080p in-focus subjects gives an un-paralleled 3D aesthetic. The contrast in the shadows is very thick and motion is top notch. 

 

Error error, that does not compute. I thought this was a myth I believed out of ignorance.

[valid]

DOF is amazing. Are you sure the blown red channel is just your grading - and not an exaggeration of the BMPCC's infrared problem in some way?

[tosvus]

Looks great aside from issues already mentioned. Practically speaking, I'd be afraid of shooting with it though - it seems really hard to keep stuff in focus. Would have to be VERY well planned shots, unless you go for some aesthetic where the subjects come in and out of focus a lot.

[kaylee]

Looks great aside from issues already mentioned. Practically speaking, I'd be afraid of shooting with it though - it seems really hard to keep stuff in focus. Would have to be VERY well planned shots, unless you go for some aesthetic where the subjects come in and out of focus a lot.

right?

so i finally saw The Master last night and that happens... a lot lol

have you guys seen this? v interesting photographically speaking

great work rich  

love the forbes 70 project!!!! wishing you all the best

[BrooklynDan]

One of the things that's gonna make medium format cinematography a real issue is focus-pulling. Obviously, at the low-end, we're all gonna be using vintage Mamiya, Schneider and Hasselblad glass. While we've been been getting away with using DSLR glass on Super 35 and full frame sensors, once you step up to that 6x6 format, it's gonna be necessary to do constant focus tweaks, even on wide shots where we could've once just set it and forget it. Because when your wide angle lenses are 40mm or 50mm, even wide shots have shallow depth of field, which of course has been demonstrated above. It's one of my favorite things about seeing movies like The Master and Interstellar. That amazing depth and focus separation. But it will be challenging as fuck.

Better start saving up to rent that Panavision 70 glass!

[Nikkor]

Focus pulling isnt really any different, the dof is as wide as the equivalent on 35mm it just pops more, you can always stop down and still get pleasant images.

[AaronChicago]

Focus pulling isnt really any different, the dof is as wide as the equivalent on 35mm it just pops more, you can always stop down and still get pleasant images.

Really? I thought it was slightly bigger than Full Frame.

[richg101]

tbh I found it easier to pull focus on Forbes70 than what I'm used to with the A7S.  for example the 180mm f2.8 + 1.4x on forbes is roughly equivalent to a 135mmf2 on full frame.  The shot where I follow focus on the model while he walks from around 100m to around 20m, unplanned shot, just pulling focus by hand with 1:1 pixels enabled.  I didn;t find this nearly as hard as it would have been with a 135mm f2 on full frame since the model jumps out so much more.  at f2, most 135mm lenses are a bit mushy meaning the in focus subject is often less refined,

With the razor sharp 180mm + 1.4x tele i could see whether he was in focus or not.  I suppose the format dictates that if a subject is out of focus it'll be more obvious, but the focus rendering actually makes it easier to focus by eye.  And working by numbers and markers after around 3 takes in a scripted shot would have been even easier.

 

 

 

Really? I thought it was slightly bigger than Full Frame.

it's not that the format dictates shallower dof.  but more how the dof is rendered.  the falloff.  for example the 180mmf2.8 + 1.4x is the same fov/dof as a 135mmf2 on full frame.  its just that the 180mm2.8 and apo1.4x will smoke (in terms of optical quality) any 135mm f2 when used wide open

[AaronChicago]

 

tbh I found it easier to pull focus on Forbes70 than what I'm used to with the A7S.  for example the 180mm f2.8 + 1.4x on forbes is roughly equivalent to a 135mmf2 on full frame.  The shot where I follow focus on the model while he walks from around 100m to around 20m, unplanned shot, just pulling focus by hand with 1:1 pixels enabled.  I didn;t find this nearly as hard as it would have been with a 135mm f2 on full frame since the model jumps out so much more.  at f2, most 135mm lenses are a bit mushy meaning the in focus subject is often less refined,

With the razor sharp 180mm + 1.4x tele i could see whether he was in focus or not.  I suppose the format dictates that if a subject is out of focus it'll be more obvious, but the focus rendering actually makes it easier to focus by eye.  And working by numbers and markers after around 3 takes in a scripted shot would have been even easier.

 

 

 

it's not that the format dictates shallower dof.  but more how the dof is rendered.  the falloff.  for example the 180mmf2.8 + 1.4x is the same fov/dof as a 135mmf2 on full frame.  its just that the 180mm2.8 and apo1.4x will smoke (in terms of optical quality) any 135mm f2 when used wide open

So the sensor of a 65mm camera is bigger than Full Frame sensor, but you just wouldn't use an f1.8 b/c the dof would be ridiculously shallow. Is that right? I always get confused when it comes to sensor comparisons.

[Nikkor]

1.8 is something like a 1.2 lens. I think the easiest way to picture this is to imagine the focal lengh you are used to but with the fov expanded to the sides. 

What richg says about it being easier to focus it's true because thhe difference between in focus and out of focus is more noticable. So while on a 35mm shot something is still acceptably sharp in 65 it will be sharper, but a little further away out of dof on 35mm you won't notice the difference as much but on 65 it makes a jump. This means that for small screens 35mm could be easier to deal with but on larger screens it's the opposite (circle of confusion,bla bla bla) This is why in cinema they have to shoot stopped down unless it's some gritty nightime taxidriver style shot where resolution doesnt matter. In 65mm you can still shoot wide open and get away with it because the actor fits into the dof without looking mostly blurry.

Get some hasselblad and watch through the viewfinder, its magical and selfexplanatory.

 

[richg101]

 

So the sensor of a 65mm camera is bigger than Full Frame sensor, but you just wouldn't use an f1.8 b/c the dof would be ridiculously shallow. Is that right? I always get confused when it comes to sensor comparisons.

indeed.  but its more that medium format lenses simply are not made much faster than f2.8, and when they are they are very rarely sharp at that aperture.  Since the 65mm format needs a 80mm lens to give similar fov to a 50mm on full frame (or 35mm on s35) the dof is naturally shallower since the focal length is longer for the same fov.    

[Kristoferman]

Can you explain the Forbes 70 a bit, rich? I must have missed the first news. This looks great though

[richg101]

Can you explain the Forbes 70 a bit, rich? I must have missed the first news. This looks great though

It's simply a dof adaptor on steroids.  a modified bmpcc inside a larger camera body, capturing an image from medium format lenses on n oversized medium format rear projection screen (made from ground glass) through a relay lens array and prism.  think of it as a macro lens filming a medium format focusing screen.  Before the 5Dmk2 came round, people were using similar things to get a 35mm format look.  it would appear even the best options back then were pretty bad quality, and there was a lot of diy stuff too.  It would appear not one of them were refined to the level they could have been.  i decided to go mental and make an ultra refined one.  its taken about 2 years of back and fourth, improving each element of the design. the most complicated part was the relay lens design getting resolution and even exposure accross such a huge area. i think the next version will be the final unit with the final refinements to make it a system suitable for dry hire use.  

[Kristoferman]

It's simply a dof adaptor on steroids.  a modified bmpcc inside a larger camera body, capturing an image from medium format lenses on n oversized medium format rear projection screen (made from ground glass) through a relay lens array and prism.  think of it as a macro lens filming a medium format focusing screen.  Before the 5Dmk2 came round, people were using similar things to get a 35mm format look.  it would appear even the best options back then were pretty bad quality, and there was a lot of diy stuff too.  It would appear not one of them were refined to the level they could have been.  i decided to go mental and make an ultra refined one.  its taken about 2 years of back and fourth, improving each element of the design. the most complicated part was the relay lens design getting resolution and even exposure accross such a huge area. i think the next version will be the final unit with the final refinements to make it a system suitable for dry hire use.  

 very impressive! Definitely keep us posted. Do you plan to make a few and rent them out then?