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FORBES70 - critique please


richg101

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Hi Chaps.

I decided to take my FORBES70 camera out to play last weekend.  I'm happy with the results but wanted to ask for some honest critique.

I'd love to hear opinions on the image quality - resolution, perceived dynamic range / highlight/shadow rolloff, colour, and general 'look' of the images.  

Please bear in mind that the current maximum res is full hd, but in terms of full hd res, how is the image looking?  

 

I'd also love to hear some views on the large format aesthetic the camera exhibits.  Maybe in comparison with the recent trailers for Hateful Eight and The Revenant.  Is the added expense over say a full frame camera and fast lenses justifiable?  is the current resolution cap of full hd a real issue?  

curious for your thoughts! - ps.  larger file available for download (and detailed info about the system) on the vimeo page

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Its an amazing look IMO, when I first saw through the viewfinder of a Hassleblad, I felt the same way. It makes the image incribly "3D" for lack of a better word, great separation between subject and background, soft looking bokeh, giving it almost a Brenizer effect. The color does seem to be a bit off, a bit overblown on the highlights, but an amazing image non the less.

 

 

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I agree with both Ricardo and benymypony, I would just add that it isn't just separation of the subject and background that makes that great 3D look but I can also perceive distance between various objects in the background. I saw the same thing in the Revenant trailer(trees in the distant background).

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Wow, a special look for sure. HD resolution looks very good to me, I don't think it's a problem with HD being the ceiling. DR looks impressive too.

As mentioned previously, there is something going on in the red channel, too much in the mids? I always noticed some black flashes in the sky at 25 seconds but guess you are aware of those.

I think medium format definitely has its place, especially with the unique looks possible at the wide end.

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Thanks for the critique so far guys.  yes, the colour thing is my fault i think.  i'm no colourist so usually find it a little hard to get both skin tones and other stuff right.  if one is right, I end up gettig the other wrong and vice versa.  I think I was a bit heavy handed in the mids on the red chanel when adjusting the footage after conform from raw.  should have done that at the raw stage!

 

The flicker is something to do with the way adobe raw adjusts the clips one by one.  occasionally this causes a shift to some of the frames.  I think its finally time i learned resolve for this stuff!!

 

 

re. aberrations.  I made sure not to use any of the clever lens fixing in raw so as to keep the optical quality visible.  i think careful use of ca reduction will be great. - the CA will be from the actual schneider lenses (these were all used wide open) rather than the internal relay lenses or prism - all of which are APO corrected for the bmpcc.

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Looks absolutely fantastic Rich.

That 40mm lens @ 1m blew me away - the out of focus background just had that painted quality to it, amazing! The same goes for the shot looking at Clevedon Pier, with the guy in the foreground in focus, from your Iscorama Forbes clip - just looked unreal.

Is full HD only a problem? Never when it looks this good & you're getting the fov of a larger format camera.

Also, if you use an anamorphic lens, the RAW files should be beyond 2k & then upscaling to 4k can be done (not ideal, obviously).

Couldn't really fault it in terms of DR etc... (won't mention the CC - I think the pasty looking Bristolian skin tones confused you!)

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Might be a good candidate for a crowd-funding campaign?  Seems to me there's space in the motion picture market for these sorts of niche products.  As a documentarian, I'd be interested using a camera like this specifically for talking head shots.  The ability to get pleasing DOF in tight spaces, like an academic's messy office, would be an useful advantage.  That reason alone is why I'm still using a 5D.

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Now is a great time to learn Resolve. I'm picking my way through it myself.

It looks very magenta and a little red to me. The tint control in the camera tab and a quick play with the offset wheel should make quick work of it. 

The detail rendering is nice and the DoF aesthetic adds a nice smooth subject separation without being unbearably shallow. The highlights clip suddenly and look a little dead though, so I'd be interested to see what you can get by protecting the highlights and bringing the shadows up in post. 

Keep us posted! :d 

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Yeah I don't have actual worries about the color, since it's raw and there was a fair amount of ND that could've had an effect. DR and rolloff looked alright, though maybe a touch overexposed? or else I just sometimes prefer slightly underexposed. Thanks for sharing! Gonna be playing with it more? It'd be awesome if you could keep sharing more as you explore

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Wow!  Great to see more from the Forbes 70 after nothing for almost two years!  The 40mm footage says it all.  The shot of the girl and the two dogs under the tree made with the 180mm and the teleconverter is great, too.

 

@Inazuma & @TheRenaissanceMan:  As I understand it, the Forbes 70 is essentially a fancy, medium-format DOF adapter, employing a BMPCC to capture the images.  Apparently, significant ND was used in these shots, possibly without an IR blocking filter.

 

@richg101:  No problem with it being HD (decent DR and pro color specs are more important to me).  On the other hand, 4K Super-16 sensors are already here, in a few machine vision cameras and in both the Blackmagic Studio camera and Micro Cinema camera (both UHD and slightly wider than Super-16).

 

Given the resources/funding to modify the optics behind the focal plane, what would be the disadvantages of using a APS-C/Super-35mm sensor?

 

Also, have you considered configuring the unit so that the lens mounts nearer to the bottom of the front?

 

By the way, in your narrated video, you mention the differences between the Alexa and Forbes 70 frame sizes.  Keep in mind that the Alexa 65 has a humongous sensor -- 54.12mm x 25.58.  However, if you could crank these things out, the Forbes 70 would no doubt get more use than the Alexa 65.

 

 To me, this is the most exciting thread since NAB!  The Dog Schidt lenses are great, but please don't let the Forbes 70 languish.

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pardon my ignorance, didn't even register that you were like the creator. very very impressive, Rich :d 

 

 To me, this is the most exciting thread since NAB!  The Dog Schidt lenses are great, but please don't let the Forbes 70 languish.

^ +1

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Looks good for sure, although I don't like the smudged corners in the wide shots.

Also, I'd love to see it compared versus full frame with bright lenses. Sony A7S + Nikon / Sigma 20mmm f/1.8, Voigtlander 35mm f/1.2, or any 50mm f/0.95 / f/1.2 will give some crazy shallow dof. Different aesthetics than big format lenses, but It would be interesting to see what's the actual difference.

 

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This looks a lot better than fullframe because the dof is "denser". The blurred corners and the color are obviously not so great.

But yes, it totally has the 6x6 feeling, great job. I think you should contact some fashion photographer and shoot a video of some fancy session in natural surroundings, this is totally great for fashion.

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cheers guys.  yes, smudged corners are something I think could be improved with better axial alignment of the relay lens array.  In this config the system is running at its base exposure of 800, with 6 stops of ND.  removal of 3 stops of the nd filtration will mean the internal relay lens aperture can be closed down by 3 stops - edge performance will improve drastically.  with a moderate improvement in overall resolution which gets to the sensor.  

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Guest Ebrahim Saadawi

Too many good things to say about the image so let's get into the bad, more useful:

1 -Most prominent issue is colours. Way, way off. Even thinner and less pleasing than an A7s S-Log2 graded improperly. Really really thin and washed out, and the tones themselves are not consistent in saturation (very high red saturation in the mids, bright magenta on his skin. Low saturation in greens, and markedly low distinction in green hues, all greens look the same block, and slightly off blues in the highs). Overall the image feels as if was painted with three crayons, light blue for sky, pink, and dark low saturation green. 

I don't know where this comes from but it doesn't look like grading error but something within the image itself, as in letting in too much IR contamination is my bet and/or bad ND colour casts since the sensor is not the problem (Black magic pocket). I've had that ''look'' from NDs before, especially when I used too much.  

2 -Highlight clipping is extremely video (abrupt, and also yellow on some shots). This could be cured by just not clipping highlights, underexposing a bit would have resulted in a way more pleasing/filmic image in my opinion if the raw image can handle the slight push up correction.

3 - Corners are not just soft, but smeared, hazy. 

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. 

Just fix any colour issues shooting might have caused + grade + don't clip and it'll be golden.

Great work. Really creative and just outstanding how you were able to construct the camera together to shoot 70mm on the BMPC with so invisible optical loss. Great, great work rich. This can really go very far if just some demos were to be shot eye-catching-ly.   

 

 

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