Letus relases 2/3 B4 Relay Lenses
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Tim Naylor
Veteran
I hear you. But wouldn't it be cool to have a HPX 3000 or something capturing a Vistavision size frame. Granted it would suck for your AC.
Again, I can't disagree with you. LoL. HPx3000 footage is so clean, a vistavision frame with something like the Ultimate would be a really great and different aesthetic altogether.
O.T. -- Have you shot Anamorphic yet, Tim? I'm dying to do it, Matty_G has already beaten me to it but real soon!
Evangelos Achillopoulos
Well-known member
Since all HD cameras are 16:9 or 1:1,78 then the sizes are:
Academy format:
For projection 20,95mm x 11,78mm (that means usable area)
Camera gate 21,99mm x 12,36mm (with slight vignette in the corners that is being cropped by projection)
Super 35 format:
For projection the format is non standard needs optical reduction or DI process
Camera gate 24,89mm x 14mm
http://en.wikipedia.org/wiki/List_of_film_formats
http://en.wikipedia.org/wiki/Super_35_film
http://en.wikipedia.org/wiki/Academy_format
So when we say academy we mean something like 21mm x 11,8mm which is almost half the full frame photographic which is 36mm x 20,25mm at 1:1,78...
Additionally RED ONE sensor size is 24.4mm x 13.7mm (slightly smaller than Super 35)... http://www.red.com/cameras/tech_specs/
So if someone wants to compete a rental against RED... needs to have at least the same format, Super 35... At least to have the same aesthetic...
Academy format:
For projection 20,95mm x 11,78mm (that means usable area)
Camera gate 21,99mm x 12,36mm (with slight vignette in the corners that is being cropped by projection)
Super 35 format:
For projection the format is non standard needs optical reduction or DI process
Camera gate 24,89mm x 14mm
http://en.wikipedia.org/wiki/List_of_film_formats
http://en.wikipedia.org/wiki/Super_35_film
http://en.wikipedia.org/wiki/Academy_format
So when we say academy we mean something like 21mm x 11,8mm which is almost half the full frame photographic which is 36mm x 20,25mm at 1:1,78...
Additionally RED ONE sensor size is 24.4mm x 13.7mm (slightly smaller than Super 35)... http://www.red.com/cameras/tech_specs/
So if someone wants to compete a rental against RED... needs to have at least the same format, Super 35... At least to have the same aesthetic...
Guys I'm a bit confused. Sorry if my terminology is a bit off, but you'll get what I mean.
The B4 relay is for projecting the output of the Letus on to the 2/3" CCD chip....I am assuming, hoping, that it's the case when you put a 20mm 35mm still lens on the Letus (for example), that you end up getting a similar Field Of View (FOV) on the 16:9 chip as ou would have if it was on a 35mm camera.
I know the aspect ratio of a 35mm camera is different and that a 35mm still lens outputs a large coverage area...bigger than 35mm film for example...but how does the Letus/B4 relay handle all of this?
Cheers.
The B4 relay is for projecting the output of the Letus on to the 2/3" CCD chip....I am assuming, hoping, that it's the case when you put a 20mm 35mm still lens on the Letus (for example), that you end up getting a similar Field Of View (FOV) on the 16:9 chip as ou would have if it was on a 35mm camera.
I know the aspect ratio of a 35mm camera is different and that a 35mm still lens outputs a large coverage area...bigger than 35mm film for example...but how does the Letus/B4 relay handle all of this?
Cheers.
Lenilenapi
Carbonite Member
Albert,
It will not give you the aspect FOV of a 20mm lens on a 35mm still camera, but what it would be on a 35mm motion picture camera which is running the film through the gate in the opposite direction - vertically not horizontally, thus the FOV is smaller. Those specs are noted by Evangelos above.
This allows them to have a lens that will work for both PL mount cine lenses as well as 35mm still lenses, but it does throw away a considerable amount of real estate from the still lens. It must be more difficult to design a zoom lens to cover both. People have argued about the aesthetic implication of the different formats on this forum.
Lenny Levy
It will not give you the aspect FOV of a 20mm lens on a 35mm still camera, but what it would be on a 35mm motion picture camera which is running the film through the gate in the opposite direction - vertically not horizontally, thus the FOV is smaller. Those specs are noted by Evangelos above.
This allows them to have a lens that will work for both PL mount cine lenses as well as 35mm still lenses, but it does throw away a considerable amount of real estate from the still lens. It must be more difficult to design a zoom lens to cover both. People have argued about the aesthetic implication of the different formats on this forum.
Lenny Levy
Right, I get it, thanks. I assume this is why Cinevate are saying that their B4 mount adapter will have a zoom function that will work for both 35mm still and PL lenses?
Dennis Wood
DVXuser Sponsor
Yes, and you'll have pics by tomorrow night 
You're correct in assuming zero crop factor (100% FOV) with both 35mm and cine lenses in one relay.
You're correct in assuming zero crop factor (100% FOV) with both 35mm and cine lenses in one relay.
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Damn! Right for once! Dennis, will the relay work with other adapters? And, the big question:
Can you 35mm adapter makers make a unit like the Pro35 that's one solid, working unit for B4 cameras?
There's a huge market out there for something more affordable than the Pro35.
Can you 35mm adapter makers make a unit like the Pro35 that's one solid, working unit for B4 cameras?
There's a huge market out there for something more affordable than the Pro35.
Thanks for all of the info...for those of you out there with far superior mathematical skills than me (that would be nearly everybody):
So what is the crop factor?
Ie a Canon FD 20mm lens in a 35mm still frame has a 84deg Horizontal field of view (source is Canon 'Lens Work').
What will it be on a B4 mount camera in 16:9 with the Letus Compact?
One more point: I would guess that there are loads of us that will never use a PL mount lens on an adapter, why not make a version that uses more of the 35mm still lens FOV?
I know that the Cinevate one does, but it's HUGE. Just not practical for doco style stuff IMO.
So what is the crop factor?
Ie a Canon FD 20mm lens in a 35mm still frame has a 84deg Horizontal field of view (source is Canon 'Lens Work').
What will it be on a B4 mount camera in 16:9 with the Letus Compact?
One more point: I would guess that there are loads of us that will never use a PL mount lens on an adapter, why not make a version that uses more of the 35mm still lens FOV?
I know that the Cinevate one does, but it's HUGE. Just not practical for doco style stuff IMO.
philip bloom
Veteran
I got both the Pro B4 relay and the EX3 relay today. Heavy! Some serious glass in there. Will be using the EX3 relay tomorrow on a shoot.
Dino
Veteran
I think any relay intended for 2/3" cameras has to provide the option of using PL lenses. The Letus relays allow for use of 35mm SLR and PL Cine lenses, albeit with Academy framing for both. A zoom is great for flexibility, hopefully the quality will match a prime relay, but the size is going to be longer than the Letus B4 Compact prime due to the extra elements needed for a zoom relay.
No question that a B4 prime relay for 35mm SLR FOV only could be built, just not sure the size of that market would be worthwhile. As a rental house, I have to have a solution that will work with 35mm SLR and PL, the Letus does that in a very small, high quality form factor, just without the 35mm SLR FOV.
Dino
Veteran
Philip,
When you get a chance, I like to know how the 1/2" relay looks vs. the EX3 stock lens? And, of course, your thoughts on the B4 Pro as far as sharpness, E t E, contrast, especially at F1.5 vs. 4.0 or 2.8. Thank you!
It is a good one size fits all, but it issuch a pity to loose that FOV though. The 14mm Canon FD would look amazing in 16:9 HD!
I think there'd be quite a big market for a 35mm still version though amoung many users who want to buy their own unit, and cannot afford PL lenses. I'm in Israel and many of the rental houses here us 35mm still lenses with the Pro35's.
I think there'd be quite a big market for a 35mm still version though amoung many users who want to buy their own unit, and cannot afford PL lenses. I'm in Israel and many of the rental houses here us 35mm still lenses with the Pro35's.
Joseph Stunzi
Veteran
It is to my understanding that the Pro35 crops even more. I've heard it crops the FOV of PL lenses by 15-30% to remove vignetting. I don't believe the Pro35 zooms to work with the larger FOV of still lenses either.
Joseph Stunzi
Veteran
I think the optics are worth the crop factor sacrifice. If you're using PL lenses... it's not biggy of course. But I think paying $4500 for a relay and $4500 for an adapter... is a little much for the SLR crowd. I may be wrong though! I may be completely wrong.
What's interesting is this test done with a Red, showing that the Zeiss SLR lenses are as good as the Zeiss Super Speed cine lenses....I would guess many people could afford the $6-$8k for the adapter-relay, but not a set of cine primes or zooms!
http://www.reduser.net/forum/showthread.php?t=13760
If the crop factor is around 50% for SLR lenses (this is what I've read re the Academy Frame, but I'm not sure) then your widest lens ie a Canon FD 15mm will become a 30mm? If this is right that ain't much for your widest lens.
Joseph Stunzi
Veteran
Vistavision is 37mm by 25mm. Academy is 22 by 16. That puts the crop ratio at like 1.6 right? 60-70% of the FOV of SLR full frame lenses. Something like that.
These are pro products. But I've heard through the grapevine that a wider version of them may come out for us SLR users! Cinevate's relay zooms. I think Letus will stick with the prime lens to get better optics. So hopefully there will be at least a EX-3 relay capable of working with full frame SLR lenses.
Heck... if they added Nikon control, you could use DX glass if you really wanted to. That's closer to the aspect ration of academy at least!
These are pro products. But I've heard through the grapevine that a wider version of them may come out for us SLR users! Cinevate's relay zooms. I think Letus will stick with the prime lens to get better optics. So hopefully there will be at least a EX-3 relay capable of working with full frame SLR lenses.
Heck... if they added Nikon control, you could use DX glass if you really wanted to. That's closer to the aspect ration of academy at least!