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Rokinon Lenses RE: Are they full frame? APS? etc

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David Smith
Rokinon Lenses RE: Are they full frame? APS? etc
on Oct 18, 2013 at 12:58:53 pm

I've been looking at the Rokinon lenses but have become a bit confused about what size sensor they are made for.

I'm not sure for example is their 14mm lens is a 14mm for Full Frame, 4/3, APS, etc.

I went to the Rokinon website and it said for some lenses but not for others. Tried calling but did not get a call back.

These are the ones I'm looking at. If anyone knows what sensor size they are made for and could let me know that would be great, thanks!

Rokinon 16mm f/2.2 Cine Wide Angel Lens for Canon - 16mm f/2.2 Cine Wide Angle Lens

Rokinon 16mm f/2.0 Aspherical Wide Angel Lens for Canon EF Mount - 16mm f/2.0 Aspherical Wide Angle

14mm T3.1 Cine Super Wide Angle Lens for Canon - 14mm T3.1 Cine


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Matthew Sonnenfeld
Re: Rokinon Lenses RE: Are they full frame? APS? etc
on Oct 18, 2013 at 4:42:29 pm

The Rokinon/Samyang/Bower lenses are all full frame. Keep in mind too that the focal length is not measured relative the the sensor crop that a lens may be designed for. The image circle though covers full frame across the line.

Co-President at fourB Productions, Inc.
Blackmagic Cinema Camera, RED Scarlet-X, Panasonic HPX170, Canon 7D
2011 Macbook Pro 17", 2.3 Ghz Quad Core, 16GB RAM
2008 Mac Pro 2.6 Ghz 8 Core, 10GB RAM
AJA IoXT, Blackmagic Intensity Pro, Blackmagic Mini Monitor
Adobe Production Premium CC, Avid Media Composer 7, Final Cut Pro Studio 3


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David Smith
Re: Rokinon Lenses RE: Are they full frame? APS? etc
on Oct 19, 2013 at 1:26:27 am

Thanks for the reply,

This is what is confusing me though: This is in the description for the 16mm lens from the Rokinon website:

It is designed for camera with cropped APS-C image sensors.

And then in gives angles for APS and 4/3 lenses but doesn't say anything about full frame.

And yes, you are right. I need to factor in the lens size if the "16mm" is for a full frame.


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Ray Zan
Re: Rokinon Lenses RE: Are they full frame? APS? etc
on Oct 20, 2013 at 4:06:27 pm

That 16 mm is the only one that is APS-C (will not work full frame) and soon will come in an MFT version as well. All their other lenses are Full frame.


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David Smith
Re: Rokinon Lenses RE: Are they full frame? APS? etc
on Oct 21, 2013 at 3:05:54 pm

Thanks for the clarification,

Just to confirm this before I buy:

If I buy any lens from the Rokinon series - except the the 16mm - I would have to do convert the lens size from 35mm full frame to the BMCC sensor to get an idea of what the correct angle of view is.

But with the 16mm lens. I should convert it from 16mm APS sensor size to to the BMCC sensor size.

If this is correct than the 24mm Rokinon on the BMCC with a 2.4 crop factor turns it into a 10mm lens;

And the 16mm Rokinon on the BMCC with a 1.6 crop factor turns into a 10mm on the BMCC camera too.

So on the BMCC both the 24mm and the 16mm would basically have the same angle of view... do I have the math correct on this??

Thanks!


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Ray Zan
Re: Rokinon Lenses RE: Are they full frame? APS? etc
on Oct 22, 2013 at 1:56:14 am

No David. First of all, you multiply and not divide. a 24 mm lens on the BMCC would be equivalent to a 55 mm lens on a full frame camera (24 x 2.27).
Second, for your purposes ignore the intended sensor size (APC-S or full frame). Just multiply by 2.27 for comparison. So the 16 mm on the BMCC is like at 36 mm lens full frame. So when using the BMCC, don't worry whether the lens is intended for full frame or APC-S, as long as it has a EF mount and use the same factor (2.26) to evaluate it. I am assuming that your reference point is full frame like most of us who come from still photography. Eventually, you will have a sense of the look of all these lenses on the BMCC and won't have to make this mental exercise. Think of the 22 mm lens as the normal lens for the BMCC and go from there.
I hope my reasoning is correct and maybe others can verify.


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Matthew Sonnenfeld
Re: okinon Lenses RE: Are they full frame? APS? etc
on Oct 22, 2013 at 3:24:52 am

Spot on Ray.

David, all that you need to know is the crop factor is a reference point that refers to the FIELD OF VIEW relative to a 35mm film or digital frame ("full frame").

Whether or not a lens is designed for a given format such as APS-C or Micro 4/3, the lenses FOCAL LENGTH remains constant. The old saying goes, "a 50 is a 50 is a 50." Basically this means that a 50 for any camera, is still a 50. Even though you may "crop" the center and have a tighter field of view.

Camera and lens manufactures do not make lenses that account for this crop numerically. The Rokinon 16mm lens is still a 16mm lens. But by saying it is for the APS-C format, all that means is that image circle is smaller and it will vignette on a full frame sensor. Mathematically though, it's equivalent field of view is that of a 26mm lens full frame, in Micro 4/3 format it would look like a 32, and a 36 on BMCC.

This is because focal length is a physical thing. It is the distance of the rear element of the lens to the focal plane (the sensor) when the lens is at infinity focus. This cannot be affected by format and as such, the field of view of all lenses of equal focal length, on any format, is measured relative to full frame.

Co-President at fourB Productions, Inc.
Blackmagic Cinema Camera, RED Scarlet-X, Panasonic HPX170, Canon 7D
2011 Macbook Pro 17", 2.3 Ghz Quad Core, 16GB RAM
2008 Mac Pro 2.6 Ghz 8 Core, 10GB RAM
AJA IoXT, Blackmagic Intensity Pro, Blackmagic Mini Monitor
Adobe Production Premium CC, Avid Media Composer 7, Final Cut Pro Studio 3


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David Smith
Re: Rokinon Lenses RE: Are they full frame? APS? etc
on Oct 22, 2013 at 1:17:24 pm

LOL thanks for straightening me out guys. I wasn't seeing the forest for the trees.

Of course mm is a length and doesn't change - lost sight of that with the the "equivalent" stuff.

I get it now :)

DOH!!!!!


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Stu Blair
Re: Rokinon Lenses RE: Are they full frame? APS? etc
on Oct 23, 2013 at 1:00:14 pm

The focal length of a lens never changes..so a lens never turns into an different focal length lens. the sensor size changes.
so take the lens, multiply the focal length by 2.3 (for BMCC, 3 for BMPC)and that will give you the approximate FoV comparison.
For example, your 10mm lens on the BMCC has the FoV of a 23mm lens on a 35mm sensor. and your 50mm lens has a FoV of 115mm lens on a 35mm sensor.

By the way i have the Rokinon 16mm lens M43 mount n the BMCC and it is a very sweet lens. extreme close focus, great edge to edge sharpness, on the cropped BMCC sensor anyway.
I'm interested to mount some 16mm cine lens on it and try those.
I would like to see how an Angenieux 12 - 120 Arri bayonet mount lens would look on the BMCC or the BMPC. So i think i'll buy one on eBay to test it out.
I have an order in for the BMPC but wont receive until Dec.


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