Tokina 11-16 Coverage

[William Seale]

What is the crop factor of EF lenses on the Scarlet?

Didn't Yoav already answer this question? Crop factor has nothing to do with the lens system, or even the lens itself. Tell me what sensor size you're using, and I'll tell you the crop factor when compared to a 35mm film camera, which will likely be meaningless if you've never picked up a 35mm film camera.

If you're asking about vignetting and how big of an image circle it can project (e.g. will it cleanly cover the Scarlet at 4k), then the lens itself comes into play as a lot of lenses these days are built for smaller sensors. But if that's what you're asking then Yoav answered it too. EF lenses shouldn't have an issue projecting an image that will cover the full Scarlet 4k sensor without vignetting as they were designed for 35mm film which is much bigger.

EF vs EF-S is actually just a different mount (EF-S lenses from canon use the white dot instead of the red dot, and those lenses are allowed to reach a little closer to the actual sensor -- though very few actually do). Crop factor happens not because of the lens, but because of the size of the sensor in your camera.

EF-S lenses are ONLY designed to fit on smaller sensors (around S35 size) like on the Canon T3i / 7D. Otherwise you will get vignetting. EF lenses will
fit on any 35mm or smaller sensor.

So what you're asking isn't about the Tokina lens (which is only designed for S35 or smaller sensors, which the Scarlet is using). But about your sensor in general.

The answer to the question I *think* you're asking is:
The Scarlet in 4K mode uses a sensor size about that of APS-C (canon t3i sensor) or about a 1.6x crop factor. So comparing to what your view angle you would get with a 35MM sensor,
you can compare it to a 17-26 lens on a canon 5D.

The Scarlet in 3K is probably closer to micro-4/3, which is about a 2x crop factor. So if you stick that lens and turn on HDRx at 3k, it'll give you a field of view similar to
a 22-32 lens on a canon 5D.

The Scarlet in 2k (DONT DO IT!!) is close to 16mm film.. 3.24x crop factor...

Phil wrote this whole thing up in a BEAUTIFUL article that you really should read http://reduser.net/forum/showthread.php?66210-Scarlet-X-Data-Sheet

 

[William Seale]

Just to clarify terms:

Crop factor - A non-specific term for a sensor that is normally a ratio of the sensor size to the size of 35mm still camera, but not necessarily. It can be useful in talking about buying/using lenses in that it expresses how much more narrow (or wide) a given lens may 'look' on that given sensor when compared to another, but it's only useful if you know how the lens 'looks' on the other camera system (i.e. if you've seen a 28mm lens on a still camera you've got a reference, and you can use crop factor to quickly calculate that, if you like how wide that image looks and want to reproduce it on the Scarlet-X at 4k, then you'd need to use an 18mm on the S-X. If you've never seen a 28mm lens on a still camera then it loses it's usefulness pretty quickly other than trying to translate when your photographer friends say things like "man the 50mm is a great normal lens on my 35mm still camera"). It has no bearing on whether a given lens will work, or work well, on a given camera system.

Image Circle - This is where the lens matters. Each lens is designed to cover a specific sensor size for various technical and historical reasons. If you try to put the lens on a larger sensor than it was designed-for then it may only put light on the middle of the sensor. If the image circle does not cover the whole sensor then it will cause vignetting, which can either describe unusably-dark areas of the image near the sides, or completely black portions on the edge the image where the lens does not reach at all. For example if you broke apart a crappy point and shoot camera and took the lens off of it and tried to use it on the Scarlet-X then you'd likely just have a small round dot in the middle of the video because it was likely designed for a tiny sensor.

Vignetting - When a lens does not cover a sensor or film from edge-to-edge with full brightness.

Field of View - A term that expresses how "wide" a given lens will look on a given sensor, normally expressed as a measurement in degrees.

 

[James Fleming]

Just to clarify terms:

Crop factor - A non-specific term for a sensor that is normally a ratio of the sensor size to the size of 35mm still camera, but not necessarily. It can be useful in talking about buying/using lenses in that it expresses how much more narrow (or wide) a given lens may 'look' on that given sensor when compared to another, but it's only useful if you know how the lens 'looks' on the other camera system (i.e. if you've seen a 28mm lens on a still camera you've got a reference, and you can use crop factor to quickly calculate that, if you like how wide that image looks and want to reproduce it on the Scarlet-X at 4k, then you'd need to use an 18mm on the S-X. If you've never seen a 28mm lens on a still camera then it loses it's usefulness pretty quickly other than trying to translate when your photographer friends say things like "man the 50mm is a great normal lens on my 35mm still camera"). It has no bearing on whether a given lens will work, or work well, on a given camera system.

Image Circle - This is where the lens matters. Each lens is designed to cover a specific sensor size for various technical and historical reasons. If you try to put the lens on a larger sensor than it was designed-for then it may only put light on the middle of the sensor. If the image circle does not cover the whole sensor then it will cause vignetting, which can either describe unusably-dark areas of the image near the sides, or completely black portions on the edge the image where the lens does not reach at all. For example if you broke apart a crappy point and shoot camera and took the lens off of it and tried to use it on the Scarlet-X then you'd likely just have a small round dot in the middle of the video because it was likely designed for a tiny sensor.

Vignetting - When a lens does not cover a sensor or film from edge-to-edge with full brightness.

Field of View - A term that expresses how "wide" a given lens will look on a given sensor, normally expressed as a measurement in degrees.

Very well put William. So much confusion is often caused unnecessarily in conversations on this forum through the imprecise use of terms and, let's face it, some terms like 'crop factor' are inherently vague or habitually misunderstood. We are all at different stages of technical development in our art so it doesn't hurt to reiterate and refine our definitions frequently. It helps make sure everyone is on the same page. I'm continually surprised how little I know. Often it's when someone is explaining the basics that I find myself thinking, 'Oh, shit! that's how it works? And all this time, I thought I knew.' For example, I realised recently I don't even really know what a 'pixel' is. What does 4K really mean? That's as basic as it gets!

Canon claims the c300 downsamples from '3.5K' to HD, 3.5K meaning the sum total of red, blue and green 'pixels' used to create a true 1080P image. I assumed a 'pixel' was made up of photosites for each colour, meaning 3.5K RGB would be 10.5K photo sites. Is this just Canon marketing spin - calling photo sites pixels so they can claim a '3.5k' camera that's really HD? Well, turns out Red's use of the term 'pixel' is similar. Epic's '5K' is not truly 5K of pixels. It debayers to 4K. I'm not sure about this but I think 5K refers to the number of photo sites from which the debayer algorithm hypothesises 4K of pixels, so it's not literally 4 colour photosites per pixel, it's less than that. ie it's making more than one pixel from each set of R,G,B,B, photo sites. Is Scarlet a 4K 25p camera? Not literally. It probably debayers to 3K or so. Not sure.. Shit, I thought I knew this. I don't even know what I'm talking about. Sure would be great to get my definitions straight.. Can someone enlighten me?

 

[Peter Majtan]

I'm paying $15K for a sensor smaller than that in my 5D? I need to wake up.

First of all the sensor in the Scarlet is FF35 - a lot closer to 5D - but this is at 5K. In 4K mode (which is the one you need to shoot motion) the sensor is cropped to a standard S35 cine size...

And you are paying $15K for RAW Digital Cinema Camera. There is so much more to it then the sensor. Your (silly) argument could be used for other cameras - like Alexa. Why pay $50K plus for a sensor smaller then 5D?!?

No offense, but if you don't understand this basic concept, you should not be buying such a cameras in the first place...

Peter

 

[Ben Coleman]

I have got to point out that the RED sensor is NOT a crop sensor.
The standard in motion picture was set more than 100 years ago. The film gate size in a motion picture camera hasn't changed, since it was constrained by the 35mm film negative size running vertically through the camera.
That size is what RED uses for 4K.
The 5D is a still picture camera. The 35mm negative on a film still picture SLR went through horizontally, allowing for a much larger area of the negative to be used by a frame. That's what the 5D is. A still picture camera that happens to do video. It is not the standard in which other motion picture cameras should be compared to. Yes, it's a larger sensor, but NOT the standard for motion picture.
So, the RED sensor is not a crop factor. I hope this clear it up!

THANK YOU for making this point. That is something that has been bugging me ever since people discovered the 5d for video.

 

[Ben Coleman]

Read this http://matthewduclos.wordpress.com/2012/02/13/there-is-no-crop-factor/

That post needs to be the first thing anyone new to the large sensor video world reads! Heck, even most of the people that have 5 and 7d's should be reading that because they are mostly clueless as well.

 

[Arnold F.]

As unhappy as this is going to make you, Peter, I have bought the camera! Brace yourself for this next bit because I think you might throw a hissy when you read it....judging by all the questions I see posted here, I think it's fair to say that 100% of the people who bought the camera didn't know one thing or another about it. While your post intended to prove that some of us here use the forum to make ourselves feel better about our knowledge, others use it to learn and be helpful. Thank you to those in the latter category who posted here. The thread has helped me.

First of all the sensor in the Scarlet is FF35 - pretty much the same as 5D - but this is at 5K. In 4K mode (which is the one you need to shoot motion) the sensor is cropped to a standard S35 cine size...

And you are paying $15K for RAW Digital Cinema Camera. There is so much more to it then the sensor. Your (silly) argument could be used for other cameras - like Alexa. Why pay $50K plus for a sensor smaller then 5D?!?

No offense, but if you don't understand this basic concept, you should not be buying such a cameras in the first place...

Peter

 

[Peter Majtan]

Arnold, with all due respect I have been nothing but helping here on the forums for quiet some time. But you have to look at the way you formed your question... And I am very much happy for you that you bought the camera - hopefully when you start working with it and the RAW images it produces you will have more appreciation for what you have paid $15K for...

 

[James Fleming]

Arnold, good on you for asking questions. Just ignore the critics. Almost everyone on this forum is extremely supportive and eager to help out and usually accepting of the fact that we all are at different stages of learning and we all have gaps in our knowledge. Don't be afraid be afraid to speak up brother.

 

[William Albertini]

Arnold, good on you for asking questions. Just ignore the critics. Almost everyone on this forum is extremely supportive and eager to help out and usually accepting of the fact that we all are at different stages of learning and we all have gaps in our knowledge. Don't be afraid be afraid to speak up brother.

++1

 

[Jeff Kilgroe]

Everyone has to ask questions like this at some point. And for people who are new to the technical side of how cameras work, the whole relationship between focal lengths, sensor sizes, and how "crop factors" relate, quantifying all of that can be a big initial hurdle.

Best advice I can give to people who are new to this or who are trying to understand the relationships between different cameras would be these points:

* FORGET ABOUT CROP FACTORS. They are an unnecessary evil device, which are improperly used most of the time.

* LENSES DO NOT HAVE CROPS OR CROP FACTORS. Focal lengths are just that, the focal length of the lens itself. Different types of lenses will be made to cover imagers (sensors / film) of different sizes, but focal length is still focal length. A 50mm is a 50mm is a 50mm, whether it was designed for 2/3" HD, FF35 or 8x10 large format.

* CROP FACTORS are just what the name implies. A factor by which to relate two different imager sizes. Their use has run rampant since DSLRs started to become available with FF35 sized sensors and even more so in the video world once those DSLRs started to shoot video. Crop factors don't have to relate to FF35 and only recently has there been such a massive assumption that they always do. In reality, as pointed out in this thread, not all formats are considered a "cropped format" and a crop factor can relate two types of imagers that are nothing close to FF35. For example, the Leaf Aptus II digital back is sold as having a "1.10X crop". And to those familiar with it's market, it makes perfect sense -- it's a 6x4.5 ("645") medium format back. At a 1.10X crop, it has a sensor dimension of 53.7mm x 40.3. No sign of FF35 relationship anywhere.

As pointed out here, in the cinematography world, cameras like EPIC, Scarlet, RED One, etc.. are really not "cropped sensor" cameras. Full aperture Super35 format is 24.89mm wide, most everything is shot at a narrower aperture than that -- typically close to "35mm Academy" size, which is oddly very similar to the 22.12mm width of RED M/MX sensor 4K resolution. Huh, who'd a thought that...? Any 35mm cinematographer or DoP who has been around a bit won't have to think how to pick focal lengths for the RED One, EPIC, etc.. APS-C and DX format DSLR's typically have a sensor width of just under 24mm or about the same as vertically-aligned 35mm film as we have in a typical 35mm cinema camera. So, one has to wonder, why anyone shooting video on a 7D, T2i, etc.. wants to think in convoluted crop factors that really don't mean a damn thing?

* ANGLE OF VIEW (AOV) IS THE VALUE THAT REALLY MATTERS. You need to know what AOV is achieved by which focal length on your intended imager size.

...Seriously, I should make an app for this. 'cuz if I had a $1 for every time I answered this sort of stuff...


/ rant off

 

[Mike Garrick]

Good point about the differences between the original 35 mm motion film gate verses the 35mm still gate. I think a lot of people confuse the 2, particularly now a stills camera shooting video (5d ii ) My question with this level of confusion now , what happens when "Monstro Sensor" hit the market ?

P.S. The Tokina works fine on Scarlet, a great lens for the price. Has anyone tried the Samyang 8mm yet?

 

[Peter Majtan]

Arnold, good on you for asking questions. Just ignore the critics. Almost everyone on this forum is extremely supportive and eager to help out and usually accepting of the fact that we all are at different stages of learning and we all have gaps in our knowledge. Don't be afraid be afraid to speak up brother.

James, it is perfectly fine to ask questions. I have never said anything to the contrary and have in fact provided answers to countless questions here including his. All I am saying is that we also think how we ask question. Adding sarcasm really does not help...

I'm paying $15K for a sensor smaller than that in my 5D? I need to wake up.

Perhaps the same question could have been worded without the "waking" part... Even then I have still answered his question that it is not (just) the sensor he is paying $15K for...

Peter

 

[Kevin Marshall]

First of all the sensor in the Scarlet is FF35 - a lot closer to 5D - but this is at 5K. In 4K mode (which is the one you need to shoot motion) the sensor is cropped to a standard S35 cine size...

The sensor in the Epic/Scarlet is not FF35 (defined as 36mmx24mm). Even in 5KFF, the image area is 27.7mm x 14.6mm, which is much closer to S35 (24.89mm x 18.66mm). The "Full Frame" in 5KFF is a bit of a misnomer...it's "full-frame" in the sense that it uses the whole sensor, not that the image area is FF35. Assuming the 5D uses it's whole width in video recording, the area used in 16:9 video recording would be 36mm x 20mm.

 

[Peter Majtan]

The sensor in the Epic/Scarlet is not FF35 (defined as 36mmx24mm). Even in 5KFF, the image area is 27.7mm x 14.6mm, which is much closer to S35 (24.89mm x 18.66mm). The "Full Frame" in 5KFF is a bit of a misnomer...it's "full-frame" in the sense that it uses the whole sensor, not that the image area is FF35. Assuming the 5D uses it's whole width in video recording, the area used in 16:9 video recording would be 36mm x 20mm.

The 5D does not use the whole sensor to record video due to the scaling (line skipping) algorithm. You will notice quite a substantial crop when you switch to video mode from still on the 5D...

 

[Cody Cha]

The 5D does not use the whole sensor to record video due to the scaling (line skipping) algorithm. You will notice quite a substantial crop when you switch to video mode from still on the 5D...

I don't think you've ever shot on 5D. It uses the entire sensor (FF35) and does not crop.

 

[Nick Morrison]

The 5D does not use the whole sensor to record video due to the scaling (line skipping) algorithm. You will notice quite a substantial crop when you switch to video mode from still on the 5D...

Um I've been working with the 5D for over 2 years, and I've never noticed a crop when shooting video. Ever.

In fact, we shot a pilot three weeks ago and my 35 1.4 felt like a 21mm.

Feel free to watch the opening shot of this pilot to see what I mean.

Password: Astronaut

 

[Jeff Kilgroe]

Currently the 5K modes on the MX sensor (EPIC/Scarlet) are wider than standard S35 or APS-C. At 27.65mm width, it's close to Canon APS-H format (which is just a fuzz under 29mm wide). Generally speaking, most APS-C / DX and Super35 glass still covers the 5K modes because the image is 1.89:1 in dimensions, meaning it still doesn't require an image circle much bigger than required to cover full-aperture Super35. The only lenses that have trouble are those which barely cover or even porthole or vignette a bit on full S35.

The Tokina 11-16 covers 4K modes and even the 4.5K modes on RED Cameras just fine. 5K modes are still "covered", but it seems there is some variation in the production of the Tokina 11-16 lenses. I own both a Nikon mount version of the lens and the Duclos-modifed version of it. My Duclos mod one fully covers 5KFF on the EPIC, I can't comment on the Nikon one on EPIC as I don't currently have a Nikon mount for the EPIC, but it does cover FF35 (Nikon FX format) at 15mm to 16mm. The image circle obvioiusly decreases in size from there on down. Jarred posted a frame from a Canon-mount Tokina 11-16 on EPIC where there was noticeable fall-off in the corners, which mine Duclos one does not exhibit. I suppose I could map this out on the Nikon image to the same dimensions of 5K on MX, but I've never bothered since my Duclos one performs brilliantly. At first I wondered if there are differences due to the conversion process, but I think it's more due to fluctuations in tolerances for the manufacture of the lens. Since then, I have run across a Canon mount version a friend has and we put it on the EPIC and it covers just fine like my Duclos one does. Your mileage may vary on this one. But it seems the lenses range from fully covering 5KFF on the RED MX sensor to showing some fall-off, even a slight vignette, in the corners. Either way, the Tokina 11-16 is a gem of a lens. Tokina is also releasing an updated version of it here in the coming months. So it will be interesting to see how that one performs.

 

[Brian Merlen]

so whats the angle of view at 1k ws with a tokina 11-16? can anyone post an image or video? i wanna buy either the tokina or the duclos but i'm trying to figure out how wide it'll be on my scarlet at 2k hd or 1k ws....


looking for those cool overcranks on a poor mans camera.... but with this angle of view/crop factor (whatever term one prefers) change I just wanna figure out if I need a 8mm or an 11-16mm....I like the stop difference of the 11-16mm, so hoping it'll be wide enough for my personal tastes at 1kws/2khd/3khd