5k Scarlet and Epic are 1.2 Crop Cameras

[Michael Hastings]

At the risk of confusing things even further...

What is most helpful to me is what focal length gives me a "normal" field of view on a particular format. Normal defined as "similar to human vision sans peripheral" which used to be 50mm on still film cameras.

Obviously its important to know whether a particular optic will vignette or not. Past that, I just want to be able to pull the right lens for the shot I am visualizing the first time. Moreover, if I am budget limited on how many primes I can have, I want to choose the focal lengths I am most likely to need.

Anyone know where I can get a decent director's finder with tons of format selections for under $300? Until that question gets a lot of responses, these kind of threads are likely to continue.

BTW - That Duclos PL version of the Tokina 11-16mm is a tremendous lens.

Cheers - #19

a cheap dslr like a digital rebel with an inexpensive zoom will work extremely well and can be found for about that on ebay and craigslist - native S35 size and just make an overlay on the screen for the smaller sensor sizes. If you must have FF35 for shooting vistavision or whatever then get an older ff dslr.

As far as the "normal" field of view it is the same focal length as the diagonal of the format (and you need the diagonal of the format to get the "crop factor" anyway).

I.e. the diagonal of FF35 is about 43mm and as I believe David Mullen has pointed out in his thread that is really a more accurate representation of the true "normal" focal length of a FF35 camera.

 

[Michael Hastings]

This is EXACTLY how I work. I use a 30mm on a APS-C sized which is like a 50mm on a FF35 sized sensor. Anything above or below that I know will be tele or wide.

But rick my point was that you and I remember that stuff because 35mm FF was about all we had for still cameras back in the day - but that hasn't been true for about ten years and since so many people already have trouble understanding "crop factor" (if you don't believe me search on it on REDUSER) I'm suggesting it is time to abandon it.

So with that, what does 50mm FoV on a FFF35 translate too on a 2/3 to be? (what focal length lens)

2/3" I believe is 8x6mm (in 4:3 -smaller height 3.8? in 16:9) so about 10mm to equal 43 on FF (so a "crop factor 4.3) but as you can see as jeff pointed out it starts getting messy with different aspect rations, so even crop factors are just ballpark. You either just need to memorize the "normal" focal length for the different formats (not that hard) or ultimately when you need to get serious you start using the horizontal angle of view and just punch it into a calculator like iSee4K.

 

[Rick Burnett]

I totally agree that it gets confusing, that said, I just got into SLR technology 2 years ago so all the crop factor stuff I have read along the way. My BIGGEST problem with a lot of discussions is that aspect ratio is important and hard for me to relate between different sizes when discussing crop. That's why I think the diagonal distance of a format really conveys the largest distance across the sensor in terms of the what the lens is going to project onto the sensor. Knowing that value, you can without question ALWAYS get the right lens that will cover the sensor. Outside of that, aspect ratio is necessary to know the H and V field of view, but that seems to make it more confusing, and is always a smaller size that the diagonal.

I personally think in terms of horizontal distance regardless of the aspect ratio as that is usually what I care most about when setting up a shot. I am sure everyone else is probably different. To me, someone just needs to come up with a standard that actually conveys all the information. With crop factors and with different aspect ratios, half the time I am scratching my head as to what to expect. It will mean more to me on my Scarlet when I can choose different aspects in camera and not after in editing.

 

[Jeff Kilgroe]

Another observation here, not a really new one, but still an observation. Most who advocate the crop factor methodology are people familiar with FF35 photography and wish to relate everything to the FOVs as they are on a full frame 35mm imager. That's fine and great except there are a great many shooters out there who are not familiar with FF35 as a format. Shocking, I know, but true. Until very recently most all DSLRs were not full frame, typically APS-C / DX format similar to S35. Many cinematographers are more familiar with focal lengths on S35 and non necessarily on FF35 still imagers.

This creates confusion within the community. Many people looking for a crop factor when they don't need one. Many people who have been shooting S35 for a long time and who are very comfortable with focal lengths and which AOVs they give on S35, are suddenly making the incorrect assumption that FF35 or "stills" glass will have a different AOV or will have a crop factor if they put it on their S35 camera.

Personally, I have never thought in crop factors as related to FF35. I think a big reason for that is I have not shot much FF35 format imagery since I retired my old Ricoh and Nikon film SLRs close to 15 years ago. Until my very recent excursions into digital still photography, I have been shooting medium format, mostly 6x4.5. And all film, too. I've never bought a digital back for my Mamiya 645 bodies. Aside from studio portrait or product photography, digital backs have been relatively worthless until very recently.

So I guess my point is that too much emphasis is placed on crop factors. Even in the still photography world. With the multitude of image formats or sizes available on all the new digital cameras, not just the ones from RED, trying to think in crop factors is going to get cumbersome. Trying to always relate to FF35, especially with many lower cost digital offerings at larger sizes just around the corner, is going to add further confusion.

I can figure the AOV / FOV of a given format with a given focal length just as fast as I can figure a crop factor as it relates to FF35. For those who slept through high-school geometry class, it's not too late. If you can figure out how to use a crop factor, you should be able to figure out how to calculate an AOV. I bet wikipedia or google can show you how anyway.

/rant off

@Tom -- I do agree with you about FF35 becoming the next dominating format for cinematic production. While final delivery will probably not migrate to 3:2 aspect ratio, but rather stay wider as it is now, there are countless benefits to shooting with the larger frame size. I think as far as the RED cameras are concerned, the real flagship camera and industry workhorse is going to be either the EPIC FF35 or the EPIC 645. I'm thinking the 645 if it comes out in the same time period, not so much for the larger sensor size -- which will be attractive to FX people and those shooting for IMAX / 70mm delivery. But because of the higher specs, frame rates, etc.. that were initially proposed, if that still holds true when they're released.

 

[Rick Burnett]

I'd say in my opinion, a FF35 sensor where a cropped portion of the sensor to S35 size was 5K (so obviously FF35 would be much higher resolution) and if you finished at 5K, this would give you the advantage of shooting FF35 or S35 for when the situation dictates. I know you could just do this with the FF35 and crop in post, I find sometimes it doesn't help me when framing a shot (but I guess with guides on the display, that won't matter).

I've shot with FF35 sensors and while they can do some AMAZING shallow DoF, I found the S35 was really a sweet spot for me personally. That said, any time I wanted really deep DoF on the FF35 or the S35, I felt both required me to stop down the lens so much, that it was hard to use at night. This is where I think the 2/3 becomes my ideal deep focus and my S35 my shallow focus go to. (Not that you can't do either on either, it's just each has a wider range in their respective sweet spot).

I do have a sincere question, when framing, do you all pay more attention to the width of your shots, or the height? I am just curios. And Jeff, I don't use crop factor at all when I discuss lens, I actually just talk sensor name since almost everyone I know gets confused EXCEPT people with FF35 still cameras. They ALWAYS talk to me in crop factor and then they too sometimes get confused

 

[Jeff Kilgroe]

I'd say in my opinion, a FF35 sensor where a cropped portion of the sensor to S35 size was 5K (so obviously FF35 would be much higher resolution) and if you finished at 5K, this would give you the advantage of shooting FF35 or S35 for when the situation dictates.

Lots of benefits to shooting with the FF35 or even larger sensors. It's not always about DOF.

I do have a sincere question, when framing, do you all pay more attention to the width of your shots, or the height? I am just curios.

For me it depends on what I am shooting, as I'm sure it does for most. But typically the horizontal dimension is your primary concern, unless you are shooting something formatted for a portrait orientation.

And Jeff, I don't use crop factor at all when I discuss lens, I actually just talk sensor name since almost everyone I know gets confused EXCEPT people with FF35 still cameras. They ALWAYS talk to me in crop factor and then they too sometimes get confused

Exactly.

 

[Rick Burnett]

Lots of benefits to shooting with the FF35 or even larger sensors. It's not always about DOF.

So what are those benefits? I am genuinely curios. I mean this past the digital technical advantages of larger resolutions or larger pixel active areas, less noise and higher sensitivity. (which are all good, don't get me wrong).

But from an optical standpoint, I am at a loss. It would require much larger more expensive and heavier lens in my opinion. That said, running in a cropped mode, you could use smaller lens and get the same performance as smaller sensors if the pixels were the same size. If this makes sense?

To me, the beauty of the 2/3 is that for deep focus, which I use in fight scenes and SFX is going to be easier to achieve in low light without the addition of lots of noise to the shots. That said, if I cropped on the FF35 to the same size as the 2/3 and then used the same lens as the 2/3, if the pixels were identical (and they are not) the FF35 could handle both cases.

This is out loud thinking in terms of the S35 for me. I wonder if running the S35 cropped, what kind of frame rate I could get out of the S35. As the other beauty of the 2/3 is 150fps.

Which brings up an even more confusing point for some. Sensors have a crop factor associated with them (as we've been discussing) but then they also run in cropped mode, and that cropped mode is normally in different aspect ratios on the same sensor adding even MORE confusion to people

 

[G Lap]

Sensors: Cinema v Stills Terminology & Rough Guide

This information is spread across the site in various threads. It might be useful as a rough ‘at a glance’ guide (with the caveat that some figures are approximate, not all source posts are RED official and everything is subject to change......of course).


2/3" - 3072 x 1620 - 3K
10.1x 5.35mm MX
native 16:9 aspect ratio, approx 11.5mm diagonal,
3.3 micron pixels, approx: 5 mpx, 3.75 FOV crop factor.

R1 - 4520 x 2540 - 4K
24.4 x 13.7mm Mysterium
native 16:9 aspect ratio, approx 28mm diagonal,
5.4 micron pixels, approx: 12mpx, 1.5 FOV crop factor (APS-C).

S35 - 5120 x 2700 - 5K
30x15mm MX
native 16:9 aspect ratio, approx 33.5mm diagonal,
5.4 micron pixels, approx: 14mpx, 1.25 FOV crop factor (APS-H).

FF35 - 6000 x 4000 - 6k
36x24mm Monstro
native 3:2 aspect ratio, approx 43mm diagonal,
6 micron pixels, approx: 24mpx, 0 crop factor (FF DSLR).

645 - 9334 x 7000 - 9k
56 x 42mm Monstro
native 4:3 aspect ratio, approx 70mm diagonal,
approx: 65 mpx, 0.6 crop factor (MF).

617 - 28000 x 9334 - 28k
168 x 56mm Monstro
native 3:1 aspect ratio, approx 177mm diagonal,
approx: 261 mpx, 0.25 crop factor (MF).


Crop Factor refers to Field of View (FOV) crop factor, or Focal Length Multiplier (FLM), referenced to Full-Frame 35mm.

APS-C (Canon1.6, Nikon1.5): Canon 7D, 550D, Nikon D300s, D90.
APS-H (Canon 1.3 crop): Canon 1D MkIV. Leica M8/8.2.
FF: Canon 1Ds MkIII and 5D. Nikon D3s/x and D700. Leica M9.
MF (Medium Format): Hasselblad, Leaf, Mamiya, Pentax, Phase, LeicaS2.

 

[Michael Hastings]

George, thanks for compiling that info.

Jeff, your post#44 did a better job than mine.

 

[D Fuller]

It's curious to me that these discussions always relate to FF35 still cameras. This is a cinema forum. Why don't we talk about "crop factors" in terms of standard 35 motion frames or S35 frames? Or S16mm if that's your background. It just seems silly that this discussion is not carried on in terms that relate to cinematography.

 

[Jeff Kilgroe]

It's curious to me that these discussions always relate to FF35 still cameras. This is a cinema forum. Why don't we talk about "crop factors" in terms of standard 35 motion frames or S35 frames? Or S16mm if that's your background. It just seems silly that this discussion is not carried on in terms that relate to cinematography.

Exactly.

But where the issue comes from is the huge influx of people coming over from the still imaging world. Add to that all the people who have been shooting on HD cameras with 35mm lens adapters for the past few years, many of which provide an image area similar to FF35.

It's been said before in many threads, including this one, crop factors are often confusing and really need a frame of reference before everyone just assumes FF35. Sorry I'm on the soap box again, but I've encountered too many shooters over the past year or two who are very familiar and at ease with shooting S35. And they are very much at ease shooting a RED One with cine lenses. But as soon as you hand them a RED One equipped with a Nikon mount, they suddenly think they need to apply a crop factor calculation because we're using SLR lenses or lenses designed for FF35. And that a Nikkor or Canon 50mm prime is going to give them a different FOV on their camera than the 50mm Zeiss prime they are already familiar with. "But I read online that the RED has a 1.6X crop factor when using still lenses".
:banghead:

There also seems to be no shortage of noobs out there who keep wanting to compare video and cine cameras in FF35 crop factor terms. And yet when I talk to them about what they're familiar with, they have hardly shot any FF35 imagery themselves (sometimes none) and own an APS-C DSLR.
:banghead:

Sorry... It's late and I'm in a weird mood. And just went through such a discussion in a pre-production meeting, about 12 hours ago.

 

[G Lap]

It's curious to me that these discussions always relate to FF35 still cameras. This is a cinema forum. Why don't we talk about "crop factors" in terms of standard 35 motion frames or S35 frames? Or S16mm if that's your background. It just seems silly that this discussion is not carried on in terms that relate to cinematography.

You're right that crop factor discussions relate to FF35 still cameras (and I can appreciate how annoying that must be to cinematographers), but it's not completely true now to say that this is just a cinema forum.....

We are in the RED Discussion section of REDUSER (RED as in the Company, not the RED ONE camera) and this is a thread about the upcoming Scarlet and Epic models. They are both DSMC's according to RED so it shouldn't come as much of a surprise that these cameras, especially the Scarlet, are attracting the attention of photographers from a stills background.

As Jeff says above, there are many people crossing over from the stills world, and in the pro stills world the buzz is all about 'convergence' and the need to be able to shoot both stills and motion in order to ride that particular wave. Whether the full-on motion capability of an Epic or Scarlet is really necessary will depend upon a project's requirements, but being able to shoot both stills and motion to professional standards with a single camera is going to be very tempting for some.

 

[Terry VerHaar]

It's curious to me that these discussions always relate to FF35 still cameras. This is a cinema forum. Why don't we talk about "crop factors" in terms of standard 35 motion frames or S35 frames? Or S16mm if that's your background. It just seems silly that this discussion is not carried on in terms that relate to cinematography.

To me, it is equally interesting that there is so much discourse and discomfort about using FF35 as a point-of-reference standard. Personally, I started shooting 35mm stills a few decades ago but wasn't very active as a photographer until I got my first digital SLR about 8 years ago. It happened to be an APS-C sensor so in order to relate it to the lenses I had for my older film 35mm, I got used to the idea of a 1.6 "crop factor." It also seemed to be a commonly accepted standard. I didn't really think about it much.

I have also been shooting video for a couple of decades and all of that has been on small chip cameras. So, in order to understand a bit about what kind of image the lenses would produce on my 1/3" sensor video cameras, it made sense to understand the "multiplier" that would give me a sense of how the FOV would relate to what I'd see if I were shooting a 35mm still camera. I knew what to expect with a 50mm lens on my still camera but didn't intuitively know what a 6 or 7mm focal length on the zoom on my video camera would look like. Hence, a "translation" language developed. I don't think I am alone, it just stuck. NOw, even if someone tells me the 2/3" sensor on the Scarlet is a 2.5 "crop" compared to an S35 Epic, I still walk through the math mentally to get back to the 3.5 crop of the FF35. But that's just me and it works for me. Again, also seems to have become something of a shorthand for a lot of people. Not right or wrong - it just "is."

That said, I am curious as to what folks who prefer the S35 as the standard would say about the "crop factor" of the FF35. Is it a number less than one (.625)? (Do people feel intuitively comfortable with that translation?)

Again, don't put me into an argument about this. I am not defending any particular approach, just explaining how one person (me) came to use this one.

 

[Andrew Walker]

Sensors: Cinema v Stills Terminology & Rough Guide

This information is spread across the site in various threads. It might be useful as a rough ‘at a glance’ guide (with the caveat that some figures are approximate, not all source posts are RED official and everything is subject to change......of course).


2/3" - 3072 x 1620 - 3K
10.1x 5.35mm MX
native 16:9 aspect ratio, approx 11.5mm diagonal,
3.3 micron pixels, approx: 5 mpx, 3.75 FOV crop factor.

R1 - 4520 x 2540 - 4K
24.4 x 13.7mm Mysterium
native 16:9 aspect ratio, approx 28mm diagonal,
5.4 micron pixels, approx: 12mpx, 1.5 FOV crop factor (APS-C).

S35 - 5120 x 2700 - 5K
30x15mm MX
native 16:9 aspect ratio, approx 33.5mm diagonal,
5.4 micron pixels, approx: 14mpx, 1.25 FOV crop factor (APS-H).

FF35 - 6000 x 4000 - 6k
36x24mm Monstro
native 3:2 aspect ratio, approx 43mm diagonal,
6 micron pixels, approx: 24mpx, 0 crop factor (FF DSLR).

645 - 9334 x 7000 - 9k
56 x 42mm Monstro
native 4:3 aspect ratio, approx 70mm diagonal,
approx: 65 mpx, 0.6 crop factor (MF).

617 - 28000 x 9334 - 28k
168 x 56mm Monstro
native 3:1 aspect ratio, approx 177mm diagonal,
approx: 261 mpx, 0.25 crop factor (MF).


Crop Factor refers to Field of View (FOV) crop factor, or Focal Length Multiplier (FLM), referenced to Full-Frame 35mm.

APS-C (Canon1.6, Nikon1.5): Canon Betacam, 550D, Nikon D300s, D90.
APS-H (Canon 1.3 crop): Canon 1D MkIV.
FF DSLR: Canon 1Ds MkIII and 5D. Nikon D3s/x and D700.
MF (Medium Format): various Hasselblad, Leaf, Mamiya, Pentax, Phase One.

Great resource. Thanks for getting all the info on this one thread. Hopefully it will hold up when Epic starts to get out into the wild.

 

[Shawn Nelson]

I thought APS-C was a 1.6 and APS-H was 1.3.

 

[Justin O'Neill]

Isn't just better to say a 50mm is
about 50 degrees on FF35 (actually 46)
28 degrees on RED/4K S35
21 degrees on 3K
14 degrees on 2K

I absolutely agree that field of view (AoV) would be the best metric to use when describing a lens. If lens manufacturers would print the FoV on every single lens life would be so much easier. Unfortunately the only metric found on all lenses is the focal length. Now if somebody can come up with a simple formula that allows us to calculate the field of view based on the focal length and sensor format we are using the problem would be solved.

Here is why I often think in terms of crop factor when trying to visualize the field of view of a lens. I most often carry around an APS-C SLR and I know in my mind what a 24mm, 35mm, etc. lens looks like on this camera. I also know this is referred to as a 1.6 crop camera. If I happen to be shooting on 5D Mark II, I know my 24mm will have 1.6 times more coverage so the equivalent field of view will be approx. 2/3 the focal length or 16mm. If I'm shooting on a 1D Mark IV the equivalent field of view is approx. 3/4 the focal length or 18mm. If I am shooting on a 2/3" chip and want to know what lens will give me the equivalent field of view of 24mm on my APS-C I divide 24mm by 2.5 and know I need approx. a 10mm lens.

My point is that these are very quick calculations I can do in my head that allow me to visualize field of view no matter what lens or format I am shooting on. If there is an easy calculation for field of view I would much rather use that.

The crop factors come from the still world but conveniently line up with REDs offerings. We have the FF35 Scarlet and Epic, the 5k Epic is approx. 1.3 crop and the RED One is approx. 1.6 crop. With RED's windowed, high speed 2k mode and the 2/3" Scarlet, it is also helpful to know the S35 to 2/3" crop factor is approx. 2.5. If I am on my RED One using a 24mm and need to shoot some high speed I know I will need a 10mm lens to match the field of view without changing perspective.

I think the reason it seems like so many people are confused by crop factors is that this is a forum where people come to ask questions and learn. It's not the everyone is confused by it, but the people who are confused post here.

When I originally made this post I wasn't advocating that people should think in terms of crop factor. I was simply pointing out what the 5k Epic's crop factor was for those who might find it interesting.

 

[Michael Hastings]

I thought APS-C was a 1.6 and APS-H was 1.3.

APS-C was a film format, Canon's "APS-C" have generally been about 1.6 while nikon's have been closer to 1.5.

The difference is so small that it is mostly irrelevant since generally you are trying to "ballpark" the field of view.

If you are trying to determine if a particular cine or EF-S type lens will cover then it is more critical but really needs to be determined by actual testing as Matt Duclos has been doing. APS-H is definitely larger but AFAIK there are no "APS-H" lenses, you just use FF35 lenses. The reason for APS-H is that it allows bigger pixels than the equivalent MP in APS-C so generally better sensitivity and the fact that the "crop factor" is useful for sports telephoto work which is one of the prime markets for APS-H cameras.

Exactly.

But where the issue comes from is the huge influx of people coming over from the still imaging world. Add to that all the people who have been shooting on HD cameras with 35mm lens adapters for the past few years, many of which provide an image area similar to FF35.

It's been said before in many threads, including this one, crop factors are often confusing and really need a frame of reference before everyone just assumes FF35. Sorry I'm on the soap box again, but I've encountered too many shooters over the past year or two who are very familiar and at ease with shooting S35. And they are very much at ease shooting a RED One with cine lenses. But as soon as you hand them a RED One equipped with a Nikon mount, they suddenly think they need to apply a crop factor calculation because we're using SLR lenses or lenses designed for FF35. And that a Nikkor or Canon 50mm prime is going to give them a different FOV on their camera than the 50mm Zeiss prime they are already familiar with. "But I read online that the RED has a 1.6X crop factor when using still lenses".
:banghead:

There also seems to be no shortage of noobs out there who keep wanting to compare video and cine cameras in FF35 crop factor terms. And yet when I talk to them about what they're familiar with, they have hardly shot any FF35 imagery themselves (sometimes none) and own an APS-C DSLR.
:banghead:

Sorry... It's late and I'm in a weird mood. And just went through such a discussion in a pre-production meeting, about 12 hours ago.

This is why the whole crop factor concept is now ridiculous - it only made sense when everybody was familiar with and understood that single common denominator FF35, but as I pointed out in an earlier post and you point out here there is no common denominator anymore.

I would also point out that this confusion was here on reduser even before the 5DMII came out. The vast majority of redusers before were video people and they used SLR comparison only because at least there was some concept that a 50mm was a "normal" a 28mm was a "wide angle" and a 135mm was a telephoto. We used the SLR comparison because virtually all shooting in the video world was with zoom lenses and hardly any of us knew or thought about what the "normal" focal length was (about 13mm I guess with a 2/3" camera like the betacams most of us "pros" grew up on). I would bet that if we lined up 100 HVX200 owners (without their cameras) and asked them what the wide and tele actual focal lengths were only 5 or 10 would know it. With video you usually just looked in the viewfinder and zoomed until it felt right. After repeatedly going full wide and wishing you had more, you bought a wide angle adapter.

Interesting side note: I just googled the HVX200 and the first article I hit was this one by Jarred Land:

http://dvxuser.com/articles/HVX200/

In depth article but didn't mention the focal length - just said 13x zoom.

Edit: found the spec on B&H website:

4.2-55mm f/1.6
(35mm Still Film Equivalence 32.5-423 mm)

 

[James Brundige]

It's curious to me that these discussions always relate to FF35 still cameras. This is a cinema forum. Why don't we talk about "crop factors" in terms of standard 35 motion frames or S35 frames? Or S16mm if that's your background. It just seems silly that this discussion is not carried on in terms that relate to cinematography.

It has been my assumption that any serious cinematographer has owned and used a SLR, and that since the Red is using DSLR technology, the terms used for still photography would be relevant and useful.

As Jeff points out, that would be any serious cinematographer over 30. All these kids around here who never got to breathe developing chemicals and wrestle with film stock in below 0 weather just don't know what they missed. I'm starting to feel old, but at least the other old guys know what crop factor means.

 

[Michael Hastings]

The discussion of "crop factors" would seem to be mostly for people new to cinematography or at least coming from the vastly different sensor sizes of video cameras.

I doubt if David Mullen or other serious cinematographers are thinking in terms of crop factors. I suspect they are used to a set like this:

Cooke S4 Set

18mm
25mm
32mm
40mm
50mm
75mm
100mm

and are pretty clear on what the angle of view is going to be with any one of them.

 

[Justin O'Neill]

I doubt if David Mullen or other serious cinematographers are thinking in terms of crop factors. I suspect they are used to a set like this:

Cooke S4 Set

18mm
25mm
32mm
40mm
50mm
75mm
100mm

and are pretty clear on what the angle of view is going to be with any one of them.

Right, but what about when he wants to shoot high speed on the RED? Does he know what the angle of view of the 18mm is at 3k and 2k? Well David Mullen might, but you get my point.