Scarlet For Beginners

[Ryan Farnes]

Ryan,

Focal lengths given in mm are always just that, the focal length of the optical path. It doesn't make any difference if they are designed for 2/3", Super35, FF35 or whatever. Different lens designs will provide coverage for different film or sensor sizes. But when referencing focal lengths, a 20mm is always a 20mm, a 50mm is always a 50mm. So if you take a 50mm lens designed to cover FF35 and put it onto a camera with a 2/3" sensor, you will get the exact same image and FOV as you would if you used a 50mm lens designed to only cover a 2/3" sensor.

Thanks for trying to help me out in understanding this. There are so many factors to take into account, I'm sure I'll eventually understand all of this stuff.

Hmmm. Haven't wanted it to be Halloween this bad since 4th grade.

 

[Jeff Kilgroe]

And wouldn't the crop factor for 2/3" be closer to 3.5x than 2x? 4/3" sensors are 2x...

I used some arbitrary numbers in that last post. But "crop factor" is really a poor way to think about relationships between camera formats. Primarily because different camera-centric industries consider different frame sizes to be the standard. In the prosumer stills and pro [D]SLR market, FF35 is considered to be the standard. In cinema, Super35 is standard and now that these various niches of the industry are starting to meld together, the crop factor mentality is making less sense. When someone asks me what the crop factor is for something, my first response is typically "in relation to what?". Crop factor is an arbitrary reference to relate two different film or frame sizes. It also doesn't help that most people don't calculate crop factors in any mathematically proper way, so they're often inconsistent and meaningless. One of the most common methods is to simply use the diagonal measurements of two frame sizes and divide the larger by the smaller. However that only makes mathematical sense if both frame sizes share the same aspect ratio. Otherwise, the numbers don't work out when applied to the FOV / AOV calculations.

So that said, It's usually best to reference only the horizontal AOV and crop factor and then reference the vertical separately if needed. Or calculate the crop factor after cropping dimensions of one of the frames being considered to account for the aspect ratio difference. A good example of this I see a lot is people saying RED One 4K is a 1.7X crop factor in relation to FF35. That's correct only if you calculate based on the diagonal measurement. In actuality, the crop factor is 1.62X and gives you different numbers when you go to figure the AOV / FOV of a given focal length.

Sorry to get all academic and long-winded here. If you take a conventional 2/3" sensor with a 4:3 aspect ratio, it typically has an 11mm diagonal. That gives you a 3.9X crop factor. But in reality, the crop factor is more like 4.09X, given you're trying to compare a 4:3 sensor to a 3:2 FF35 frame. However, some 2/3" "HD" sensors are a bit wider than the typical 8.8mm width of 4:3 2/3" sensors. Also some image magnification takes place when adapting B4 mount glass, which is designed for a 3-chip prism, to a single-chip CMOS sensor, due to optical correction. So B4 lenses cover 2K on the RED One, which is 11.06mm wide, which is wider than 16mm (10.26mm), but not quite as large as Super16 (12.52mm). ...And 2X is the crop factor for 2K modes in relationship to 4K, obviously.

 

[Joshua Brown]

Michael, I saw you already started the page on RED-Wiki.net but maybe weren't sure how to go about it. I've started the page there for you and am working on formatting.

http://red-wiki.net/wiki/Scarlet_For_Beginners

-J.A.Brown

 

[avnoj30]

Manual Lenses

Manual Lenses

In reading about the f mount- it talks about electronic Nikon lenses.

I have some Manual Zeiss ZF 35mm Lenses:
Zeiss Planar T* 1.4/85 for Nikon F-mount
Zeiss Planar T* 1.4/50 for Nikon F-mount
Zeiss Distagon T* 2/35 ZFNikon F-mount
Zeiss Distagon T* 2/28 for Nikon F-mount

Will I be able to use these Manual primes with the Scarlet Interchangeable Model?

 

[Casey Ryan Stone]

After reading some of the posts here in the Scarlet section, I figured I might be able to save some people some time by offering my notes. They are not at all inclusive - there's nothing here about how to change lens mounts, how to achieve 35mm DOF on a 2/3" sensor, or even what the difference is between an f stop and a T stop (which is not to say that there couldn't be in the future...).

F-Stop is how much light you are letting into the lens.
T-Stop is how much light actually makes it through.

Basically F-stop is a good guess, T-stop is exact.

More reading on the subject... http://www.scarletuser.com/showthread.php?t=882



Getting shallow depth of field on the fixed lens scarlet.

For the thinest DOF possible, zoom all the way in, and open the aperture all the way up to your lowest t-stop number. Thats as blurry as your gonna get.

Interchangeable lens versions are the same except you attach your longest lens instead of zooming in for max DOF.

Telephoto's get you a thinner depth of field because of the magnification in the lens.

More in depth reading on DOF... http://www.cambridgeincolour.com/tutorials/depth-of-field.htm



I see a lot of people worried about the 2/3 not giving them enough DOF, welp take a look at Izzy. http://redgrabs.com/izzy/

Jarred shot this on a test 2/3" Mysterium-X sensor Scarlet with a 100mm RED Pro T1.8 lens at T5.6.

Jim]

Not much distance between an Iguana's front shoulder and nose. Thats pretty thin DOF already, enough for me anyway, and the lens they used could go another 3 stops wider, making it even thiner, and the fixed is supposed to be T2.8 (Don't quote me on that, was in the original Scarlet specs from years ago I think) which could go another 2 stops wider.

In reading about the f mount- it talks about electronic Nikon lenses.

I have some Manual Zeiss ZF 35mm Lenses:
Zeiss Planar T* 1.4/85 for Nikon F-mount
Zeiss Planar T* 1.4/50 for Nikon F-mount
Zeiss Distagon T* 2/35 ZFNikon F-mount
Zeiss Distagon T* 2/28 for Nikon F-mount

Will I be able to use these Manual primes with the Scarlet Interchangeable Model?

The nikon f-mount has been the same sense 1959, weather electronic auto-focus or manual. Just read some of the previous posts about field of view, your glass will look like longer focal length lenses on a 2/3 sensor then they would on a APS-C, super 35, or full frame sensor.

I love these type of positive helpful threads, kudos to everyone.

Casey

 

[avnoj30]

The nikon f-mount has been the same sense 1959, weather electronic auto-focus or manual. Just read some of the previous posts about field of view, your glass will look like longer focal length lenses on a 2/3 sensor then they would on a APS-C, super 35, or full frame sensor.

I love these type of positive helpful threads, kudos to everyone.

Casey

I wasn't really worried about physically mounting them... I got these to use with the redrock cine adapter- and they've been great. But when I try to use them with the D90 DSLR- it seams I get lower quality images then with the electronic Nikon lenses- they seam grainier and sometimes have color issues... so I guess my question is: does the Scarlet interface with any electronic features of the lenses- and will using manuals limit any features on the camera itself... I guess I'm curious about how a manual lens transfers any info to a raw file... or is all the raw data just data from the brain... (sorry if this is a dumb question : )

 

[Jason Madeja]

Not much distance between an Iguana's front shoulder and nose. Thats pretty thin DOF already, enough for me anyway, and the lens they used could go another 3 stops wider, making it even thiner, and the fixed is supposed to be T2.8 (Don't quote me on that, was in the original Scarlet specs from years ago I think) which could go another 2 stops wider.

Does 2.8 seem a little slow? Does that mean 2.8 through the entire zoom of the lens, or is that just at the extreme telephoto range? Most zoom lenses give a range, right? but I've only seen T2.8 quoted for the Scarlet fixed.

 

[c-well]

So on the bigger brain you get better res, with less frame rates, I guess it all depends on what your needs are. As of late I've been shooting less ramped footage anyway so FF might be the way to go (better dof greater control on imagery).

 

[David Rasberry]

Does 2.8 seem a little slow? Does that mean 2.8 through the entire zoom of the lens, or is that just at the extreme telephoto range? Most zoom lenses give a range, right? but I've only seen T2.8 quoted for the Scarlet fixed.

T2.8, if that is what the lens turns out to be, will be constant thru the zoom range. This is an important property of motion picture zooms, as you don't want your exposure changing during a zoom move. T2.8 is pretty fast for a zoom lens.

 

[Lawrence Bansbach]

Does 2.8 seem a little slow? Does that mean 2.8 through the entire zoom of the lens, or is that just at the extreme telephoto range? Most zoom lenses give a range, right? but I've only seen T2.8 quoted for the Scarlet fixed.

T2.4 was the most recent spec mentioned, but, like everything else, that's subject to change.

 

[Ben Norton]

I have been lurking here since Scarlet was announced and will be ready to go when Red are. This is more passion than profession for me (at the moment)….allowing my inner geek to play with my inner creative.

I was hoping someone could put me out of my misery and answer the following question(s)…..I think that I may have read too many threads and the answer is starring me in the face.

I have a number of lenses for my DSLR (for example - Nikon AF-S 70-300mm f/4.5-5.6 VR). Am I correct in assuming I will need to look at the S35 to get the most benefit from them as the 2/3 sensor is much smaller (based on Jeff’s and Michael’s posts).

Or am I missing something and the world of lenses for moving image is something completely different?

 

[Gerald Menclik]

Depends on what Nikon camera your lens was working ..... sensor size is different between the i.e. D70s and the D300s - as were the sensor of the D70 is (I believe) APS-C and sensor of the D300 is 35mm .....

 

[Ben Norton]

I use it on a D40 and D5000. It will also work on the full frame Nikons like the D3.

 

[Gerald Menclik]

yes, but the sensor coverage and the focal length changes dramatically

 

[Thomas Mark Schaefer]

Time to update the FAQ?

 

[Michael Olsen]

Updates will be forthcoming.

Regarding the usage of still camera lenses on the 2/3" chip.

My understanding of this issue, and please correct me if I am wrong, is that using a still lens should be no problem with the 2/3" chip assuming the proper adapter is available. I don't think focal flange length will be a problem, in that regard.

Crop Factor - Some of you may have read my posts on DVXuser about this.

Sensor size does not increase or decrease focal length - a 50mm lens will not transform into a 100mm lens or a 30mm lens.

All that will happen is that the sensor will see more (vignetting) or less (cropping) of what the lens projects. So you will either get a black area around the image, or your image will be a smaller part of what a larger sensor could have seen.

 

[Giovanni Andreotta DoP]

Hi, I'm new for this forum but a enthusiastic red user.
But now I'm waiting for Scarlet, of course, specially on the 2/3 cinema version.
I want to use on it my two zoom lenses Canon HD-EC T 2.1 ( 4,7 x 11 and 7,8 x 21 KLL ).

I read that this is not possible because there are made for 3CCD and not for one C MOS. I'ts correct? I need an adapter?
What kind of adapter I need???

 

[David Nardini]

Scarlet Fixed x8 focal length ?

Scarlet Fixed x8 focal length ?

Anybody know what the Scarlet Fixed x8 lens will be (from<=>to focal lengths) ?

 

[Sylvain Lesperance]

sound

sound

Hi there,

What about the sound on the scarlet camera . will it be equipped with xlr entries like other camera of the same type? Will i be able to mount a mike on the camera? If yes, how much sound track will be available on the camera.

I am a documentary filmaker and I am filming alone most of the time. So I need a camera that will permit me to shoot images and record sound by myself.

Thank's

Sylvain

 

[Cedric Akins]

Hi there,

What about the sound on the scarlet camera . will it be equipped with xlr entries like other camera of the same type? Will i be able to mount a mike on the camera? If yes, how much sound track will be available on the camera.

I am a documentary filmaker and I am filming alone most of the time. So I need a camera that will permit me to shoot images and record sound by myself.

Thank's

Sylvain

No XLRs on camera, but there will be 2 1/8" mono mic inputs with phantom power. Also the I/O modules will also have XLR inputs which gives you a total of four channels of audio @ 48kHz @24bits.
AWESOME!!!!!!! :smile:arty: