Super 35mm Crop Factor and a "Normal" lens.

C

Chad Nikolaus

Active member
I've been researching lenses for the FS700 like mad, and i'm very interested in a "Normal" lens. I was looking at the 50mm 1.8 prime, thinking 50mm was usually considered "normal." (Hitchock's favorite!) However, i forgot about crop factor, then came across this chart...

http://www.dvxuser.com/V6/showthrea...actor-35mm-Motion-Picture-film-and-Micro-4-3s

And i wonder if i should be looking for a 35mm lens instead for this camera as a Normal lens?

I've been full of questions lately, so thanks for the replies, everyone.
 
I have been wondering exactly the same thing. I have also been given completely contradictory answers to this in the past so it'll be really good to find out the definitive answer.
 
Your crop 'FOV' is dictated by your sensor. Think of this as a maximum size your sensor can show when a lens put on the front of the camera.

FS100/700 is based on a 16X9 S35mm sensor.

The whole crop factor things is based on the comparison between fullframe still sensors (ie 5DMKII etc) vs 35mm. 35mm cine is the comparison factor you want.

Look here - http://www.abelcine.com/fov/ and select a given lens on 2 cameras. It shows you how the FOV increases or decreases depending on the sensor/camera... but the lens is the same.

Hope that helps.
 
So what lens did Hitchcock use? 35mm or 50mm?

I'm sure most of us here understand the crop factor, the question is the is it 50mm before or after crop is taken into consideration?
 
Here is the definitive answer... There is no crop factor!

The whole idea of a crop factor first raised its head with the introduction of the DSLR camera. People that had been shooting with a 35mm still film camera realized that at the time, the sensor in these cameras was smaller than the 35mm still film frame. So manufactors included information stating the difference between the sensor size in the camera compared to a 35mm still frame. For example 1.4x crop.

In the world of cinematography there was never a crop comparison. Cinematographers never compared the 35mm motion picture frame size to a 35mm still frame size because 35mm still cameras could not shoot motion/video. They never said to themselves, hmmm if I am using a 50mm lens on my Arri 35BL II, what's the crop factor compared to a Nikon F2S 35mm still camera. They knew what a 50mm lens looked like on their camera. Bottom line, you need to know what a 50mm lens looks like on your camera, rather than fretting over what it might look like on a different camera, like a 5Dmk II for example. The only time a crop factor is relivent, is if you need to match a shot done with a different camera that has a smaller or larger sensor than the camera you are currently shooting with. If Hitchcock said he used a 50mm lens, then he used a 50mm lens. Not a 35mm, there was no crop factor.

All the Best!

Dave
 
Nirv said:
So what lens did Hitchcock use? 35mm or 50mm?

I'm sure most of us here understand the crop factor, the question is the is it 50mm before or after crop is taken into consideration?
Click to expand...

I thnk thats a very valuable question, Ive been wondering the same.

That being said, coming from a FF 5D3 user, I don't really think it matters anyway. Its all personal preference and experimentation, I would only take these "standards" with a grain of salt. Personally, the only way to know which lenses you want to shoot with is to try a set of primes. And not just once. Obviously that takes a little budget but that's what did it for me. Discovered which lenses I used the most and loved the most, without really caring about the fact that I should have a normal lense. Say on the 5D I prefer 85mm and 35mm, not 50mm.

I'm just saying it's good to have guidelines as to which lenses will probably fit your taste, and help you buy your first couple lenses, but you'll never know until you try them on your camera for a little while.
 
Clears a lot up, and that AbelCine FoV Calculator is great too.

I see just what David is saying too, and i can't wait to get my hands on the camera to really get a feel for what lenses look like on it! :)

I looked it up just for kicks and Hitchcock shot Psycho with a 50mm lense on 35mm film. Looking at the AbelCine FoV Calculator, there's not much of a crop from 35mm Film to Super 35mm. Looks like you'd go 47.5mm for the same effect on the FS700. I could be reading it wrong! Interesting, lol.
 
How does one define "normal"? I always understood it to mean that the lens shows an image similar to what the eye sees. But human vision has peripheral ability while cameras do not, so there is no true normal lens. However, obviously a long telephoto is not normal, and neither is super wide. IMHO on this camera normal is somewhere between 28mm and 35mm, but I'm sure some will disagree.
 
On a full frame camera, the "Normal" is considered 50mm.

Therefore, on super 35mm (that has a 1.5 crop), the equation is 50mm / 1.5 mm = 33.33mm.

So for a prime, you closest would probably be a 35mm to be considered normal.
 
stevedocmaker said:
How does one define "normal"?
Click to expand...

In photography (and I presume cinematography too), a "normal lens" is one with a focal length close to the diagonal of the capture area. So for S35, the frame size is 24.0 x 12.97 mm (Academy Ratio), resulting in a diagonal of 27.28mm. That would make a 28mm lens about normal for the format.

But it turns out that people tend to prefer something a little longer than the diagonal as their normal lens. I don't know why, but it's true from 35mm "full frame" cameras up through 10x8 large format cameras. So I'm guessing that a lens in the 28-35mm range would do fine as a normal lens for S35.

Only way to know for sure is to try it and see how you like it.
 
There's been a tendecy for the "normal" lens to go wider with the movie frame going wider. 50mm was "normal" in the time of the Academy format frame with aspect ratio of 1.375:1. Back then it was also the fastest lens. In terms of image perception the "normality" depends on the projection frame and not on the popular diagonal of capturing frame definition. The wider frame naturally accommodates wider focal lengths. So 35mm is more normalish these days. Some people use 32mm but this is a rare focal length for still lenses.
 
cpc said:
There's been a tendecy for the "normal" lens to go wider with the movie frame going wider. 50mm was "normal" in the time of the Academy format frame with aspect ratio of 1.375:1. Back then it was also the fastest lens. In terms of image perception the "normality" depends on the projection frame and not on the popular diagonal of capturing frame definition. The wider frame naturally accommodates wider focal lengths. So 35mm is more normalish these days. Some people use 32mm but this is a rare focal length for still lenses.
Click to expand...

cpc-

interesting point.

thanks for sharing.

be well.

rob
smalltalk productions
nyc
 
This According to Roger Deakins... "Technically speaking a 50mm lens is considered 'normal'. The calculation is made in regard to the optimal viewing distance in a theatre and 'normal' meaning there is no distortion of view for the observer."

Many feel that a 45mm lens most closely resembles what the eye sees.

While I do not have a lens that lives on my cameras, I use a 35mm and 28mm quite a bit. One factor to think about when choosing a lens is the distance you will be working from your subject. While everyone would love the ability to work on a large sound stage with moveable walls on their sets, more times than not we are limited by the area we have to shoot our subject, so lens accordingly.

All the Best!

Dave
 
Nirv said:
So what lens did Hitchcock use? 35mm or 50mm?

I'm sure most of us here understand the crop factor, the question is the is it 50mm before or after crop is taken into consideration?
Click to expand...
If Hitchcock said a 50 was his favorite lens, it would assuredly be without any reference to crop factor! It would have meant a 50mm lens as used on a 35mm motion picture camera.

If anyone would have tried to lecture Hitchcock about a "crop factor", he would have slapped them.
 
stevedocmaker said:
How does one define "normal"? I always understood it to mean that the lens shows an image similar to what the eye sees. But human vision has peripheral ability while cameras do not, so there is no true normal lens. However, obviously a long telephoto is not normal, and neither is super wide. IMHO on this camera normal is somewhere between 28mm and 35mm, but I'm sure some will disagree.
Click to expand...
It refers to perspective rendering ONLY. It doesn't refer to angle of view or periphery or anything like that, it refers only to the magnification of the image in relation to what the eye sees, and at what distance the camera would be positioned in order to deliver the proper perspective at that magnification.

As such, the focal length that's "normal" is relative to the size of the image sensor. Smaller formats need wider lenses to render that magnification at normal perspective distances; larger formats require longer lenses to render that magnification at normal perspective distances and image size.
 
Wow, I can't believe some of the overly-complicated and emotional answers people are giving to this clear question. The OP wanted a simple answer, and there is a simple answer.

Chad: For a camera with an APS-C sized sensor like the FS700, the closest widely-available focal length for a lens that will give (what's commonly referred to as) a "normal" field of view is 35mm.

You want a 35mm lens to get close to the look Hitchcock favored. A 35mm lens on APS-C won't match EXACTLY (in framing or perspective), but it's very very close, and it's a widely-available focal length.

This is due to the difference in frame/sensor size between the format Hitchcock would have used (most certainly either unmatted/"Academy" or matted/"Flat" or anamorphic/"Scope") - and today's Super 35 (film) and APS-C (Photo, and now, video) sensors.

There, that wasn't so hard, was it guys?

Also, OF COURSE no one would have "lectured" Hitchcock on "crop factor" (I don't know why such loaded phrases even need to be brought forth)... but you'd better believe that - if Hitchcock was shooting a television episode on 16mm film - he either already knew he couldn't use his favorite 50mm lens for a "Normal" look (likely), or else his smart and tactful DoP would have said "Correct me if I'm wrong Sir, but we need a shorter focal length for a shot like that with 16mm"...had Hitch suggested it.

Why do we have to get so bent out of shape and extreme any time anyone mentions "crop factor"?

The difference in lens selection for equivalent framing and field-of-view between different film and video (sensor size) formats is a VERY REAL THING.

Choosing a set of lenses, or an individual lens (for purchase, or use in a shot) based on format and Focal Length Multiplier is a VERY REAL THING.
 
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cpc said:
There's been a tendecy for the "normal" lens to go wider with the movie frame going wider. 50mm was "normal" in the time of the Academy format frame with aspect ratio of 1.375:1. Back then it was also the fastest lens. In terms of image perception the "normality" depends on the projection frame and not on the popular diagonal of capturing frame definition. The wider frame naturally accommodates wider focal lengths. So 35mm is more normalish these days. Some people use 32mm but this is a rare focal length for still lenses.
Click to expand...

Bingo! CPC explains it perfectly again. Every time you post I learn something valuable, many thanks.

This was exactly the root of my question which I made a characteristically poor effort at asking.

So Hitchcock's 50mm gave him a FOV we'd get out of a 35mm-ish.

Cheers
 
its subjective to the individual.

For me a 35mm focal length gives me a normal field of view. I also use 28mm for this purpose as well.
 
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