OK, Now I'm confused (Focal lengths 35mm film vs FF and crop sensors)

[gibbo]

I'm confused about focal lengths on 35mm cameras vs FF sensor cameras (Canon 5D etc)

EDIT: Scroll straight to the bottom edit for my actual question Sorry about the length of the post!

EG:

I've read/heard the 50mm lens recommended by a lot of people, for example, Philip Bloom has said on his blog that everyone should get a 50mm and learn off that, most of my photography friends say the same and just from my person experience a 50mm (FF equivalent) is a great focal length for a general all round lens. No problem here because they were all talking about a 50mm full frame still sensor/film equivalent focal length which is a quick and simple calculation to get to.

So, the confusion comes when I throw a 35mm camera into the mix, I read that Steven Speilberg said if he could only use one lens it would be a 50mm, likewise with James Cameron and apparently Psycho was filmed mostly on a 50mm but a 50mm on 35mm cameras is very different to a 50mm on a FF Sensor camera.

35mm still film/FF sensor are the same right? So a 50mm on these 2 would be the same. However, 35mm motion picture film is smaller so the same 50mm lense would have a different FOV.

So, 35mm film and S35mm film (these have similar widths but different heights, correct?) are much much more like an APSC crop sensor camera like my t3i, you can see here that if you choose S35mm film and a Canon 7D to compare they are almost the same:
http://www.abelcine.com/fov/

So, would the 50mm focal length being spruked actually be on a 35mm equivalent, closers to 80mm, not like a 50mm on a FF stills/sensor camera?

EDIT:I've read that both a 50mm lense on a 35mm camera and a 50mm on a FF Sensore camera are close to the "Normal FOV" but they are different. Which one of these sides is wrong?

[IndieBudget]

http://www.cambridgeincolour.com/tut...ensor-size.htm

Some cams like the T21 etc have a 1.6 crop factor

So you would need a 28 or a 30mm lens on a APS-C ( 1.6x crop factor ) lens to get the same image as a FF w/ a 50mm lens Im thinking











.

[gibbo]

Thanks for the reply indiebudget, I'm aware of the crop factor and that I would need a 31.25mm lens on my T3i to achieve a 50mm equivalent.

But my problem is not that, it's actually the difference between a 50mm on a 35mm motion picture camera and a 50mm on a 35mm stills camera (FF Sensor or Film which are the same size).

They both say 50mm is the same "normal" field of view etc, but the 35mm motion picture camera film is closer to an APSC size sensor (t3i, 1.6 crop factor) so in reality, a 50mm on a 35mm movie camera should be closer to an 80mm on a Full frame still camera.

That's my confusion!

[Ernest Worthing]

I cant seem to dig up my older posts from more than a year ago when i went into length about these topics.

In short, a 50mm is a 50mm and an 85 mm is an 85mm. Their inherent qualities remain the same. Their perspective, their compression etc etc. A lot of ppl get confused about this because things look different in their tests. What they are not taking into account is keeping the same lens to subject distance. When you move to get the framing you want, the distance between lens, subject and background changes and things will look different.

Field of view is different and is a relative term. You have a t3i, correct? Your 1.6 crop factor is close to S35 as it is. Dont worry about focal length equivalents or crop factors. Get the lenses you want which give you the look you want. The lenses are not affected by these factors. Once again, their inherent qualities stay the same. Your fov changes because of the sensor and as long as the sensor isnt anything extreme in any direction, dont worry about it.

[gibbo]

Originally Posted by Ernest Worthing

I cant seem to dig up my older posts from more than a year ago when i went into length about these topics.

In short, a 50mm is a 50mm and an 85 mm is an 85mm. Their inherent qualities remain the same. Their perspective, their compression etc etc. A lot of ppl get confused about this because things look different in their tests. What they are not taking into account is keeping the same lens to subject distance. When you move to get the framing you want, the distance between lens, subject and background changes and things will look different.

Field of view is different and is a relative term. You have a t3i, correct? Your 1.6 crop factor is close to S35 as it is. Dont worry about focal length equivalents or crop factors. Get the lenses you want which give you the look you want. The lenses are not affected by these factors. Once again, their inherent qualities stay the same. Your fov changes because of the sensor and as long as the sensor isnt anything extreme in any direction, dont worry about it.

Thanks Ernest, I do have a t3i, decent little camera and I really hope SOMEONE can figure how to do uncompressed recording.

I'm aware that the actual focal length doesn't change that's why I mentioned that the FOV changes. I'm also aware that actual focal length choices are a subjective matter. I prefer 40mm (FF equiv.) over a 50mm equiv. to be honest and I don't like any barrel distortion as it draws attention to itself (I'm a realist!) so too low = no no. I also hate the 50mm on my camera unless it's for portraits and MCU's, I just find the FOV really arkward to work with for general usage.

I just wanted to know about this 35mm movie camera Vs. full frame sensor camera for my own general knowledge as it's confusing me that lots of people love the "50mm" but the actual FOV would be different/...

[wheatgrinder]

vimeo is your friend. search for the camera and lens combo your curious about.

50mm even on a crop sensor (which is all Iv ever known) is my favorite lens. It just is..

[jax_rox]

Keep in mind that 'crop factor' is not something anyone really talked about the way it is now until the advent of DSLR filmmaking. 16mm primes were essentially half of their 35mm equivalents, so a set would/does come with a 9.5mm, 12mm, 18mm, 25mm and sometimes a 50mm. That was essentially the extent of 'crop factor'. DSLR moviemaking brought with it this different species of user who were used to Full Frame stills. Whether 50mm on a Master Prime is in relation to a 35mm camera or a FF camera I'm not sure - and I don't really care to know. I'm used to working on that sensor size (as well as 16mm sensor size) and I know what they look like. DSLR filmmakers have put a stupid amount of importanec on sensor size and crop factor as if no crop factor is somehow better even though S35mm is very close to an APS-C size sensor, and even 5k has a 1.3x crop factor. At the end of the day it doesn't really matter anywhere outside of the world of DSLR. PL lenses (which most cinema cameras use) vignette on a Full Frame stills camera, which is why Epics @ 5k tend to use Ultra Primes and a select few Angenieux Optimos because they vignette much less.. so what does that tell you about ff?

[Ernest Worthing]

Originally Posted by jax_rox

DSLR filmmakers have put a stupid amount of importanec on sensor size and crop factor as if no crop factor is somehow better even though S35mm is very close to an APS-C size sensor,

I've been posting this here for years.

@OP: Im not sure i understand the confusion you have over two people with two different sensor sizes both liking the 50mm.

Im earnestly trying to answer your question but i would just be repeating myself again about the inherent qualities of the lens being the same while the fov from the same distance would be different. And once again, dont worry abt a 1.6 crop. Move yourself, your subject in relation to the bg the way you want to frame the shot.

Maybe im not understanding you correctly.

[Kholi]

Actual answer to your question:

CInema world does not refer to things from a Full Frame perspective, so in Cinema world 35mm is the normal.

In Full Frame world, that equals a 50mm.

Both are normals, depending on which world you come from.

Neither are wrong.

On the same hand, a 50mm could be considered a normal, so could a 40mm, the change is distance from lens to subject to present what would be a "normal" view.

[Cracker Funk]

To me, the whole issue of lens conversion really only matters if you come from a particular photographic background and therefore have visual expectations when a particular focal length is mentioned.

It's good to understand the issue, how crop factor differs from full frame, and how full frame 35mm is not the same as cinema 35mm. But for practical purposes, I think it best to just try the different lenses on for size. I think it's interesting that wheaty's favorite combo is 50mm on a crop factor -- wouldn't that be the closest to the 50mm cinema look that we're accustomed to?

[brianluce]

I'm a 50mm fanboy too.

[gibbo]

Originally Posted by Ernest Worthing

I've been posting this here for years.

@OP: Im not sure i understand the confusion you have over two people with two different sensor sizes both liking the 50mm.

Im earnestly trying to answer your question but i would just be repeating myself again about the inherent qualities of the lens being the same while the fov from the same distance would be different. And once again, dont worry abt a 1.6 crop. Move yourself, your subject in relation to the bg the way you want to frame the shot.

Maybe im not understanding you correctly.

Yeah I'm not very good at explaining myself most times, but good at confusing myself and other in the process! Sorry....

What I mean is:

Hithcock used a 50mm in Psycho quite a bit because it replicate the FOV and perspective of the human eye. In a scene like the peeping through the peep hole scene for example. Psycho was shot on cinema 35mm, so a 50mm on cinema 35mm is very close to a 50mm on my t3i, around 80mm give or take?

Other filmmakers have said that they love the 50mm as well, Speilberg has said this too, so I assume he's talking about a 50mm on cinema 35mm?

Other filmmakers have said 50mm is a great all round lens and a favourite too, so I assume that they mean 50mm on cinema 35mm.

Now, Philip Bloom says he can't recommend enough a 50mm lens either, but he means 50mm on a FF sensor (he was testing the GH2 at the time and had a 25mm on it which approximates the FOV of 50mm on a FF sensor)

So all this time I was thinking that all these filmmakers loved 50mm, I thought it meant equivalent to a 50mm on a FF sensor camera, so around 30mm on an APSC sized, or 30mm on cinema 35mm etc. But they are two different FOV completely!

Originally Posted by Kholi

Actual answer to your question:

CInema world does not refer to things from a Full Frame perspective, so in Cinema world 35mm is the normal.

In Full Frame world, that equals a 50mm.

Both are normals, depending on which world you come from.

Neither are wrong.

On the same hand, a 50mm could be considered a normal, so could a 40mm, the change is distance from lens to subject to present what would be a "normal" view.

So both 50mm on cinema 35mm and 50mm on FF sensor are both 'normal' even though they are really 30mm apart? (50mm on cinema 35 = around 80mm) I thought 80mm was just starting to get into very short telephoto territory?

I find 50mm on a FF sensor a lot more pleasing to the eye than 50mm on a APSC (80mm on a FF sensor, it's awkward) and even would say that 40mm on a FF is even more pleasing IMO.

Originally Posted by Cracker Funk

To me, the whole issue of lens conversion really only matters if you come from a particular photographic background and therefore have visual expectations when a particular focal length is mentioned.

It's good to understand the issue, how crop factor differs from full frame, and how full frame 35mm is not the same as cinema 35mm. But for practical purposes, I think it best to just try the different lenses on for size.

I really do want to learn it mainly for my personal knowledge, I prefer 50mm on a full frame than 50mm on cinema 35mm.

I think it's interesting that wheaty's favorite combo is 50mm on a crop factor -- wouldn't that be the closest to the 50mm cinema look that we're accustomed to?

Yeah that's what I'm trying to get at... it seems too 'narrow' and cramped to be considered 'normal', 50mm on a FF seems to be more 'normal' IMO

Thanks for the lingo BTW (Cinema 35mm)!!!

[Cracker Funk]

Originally Posted by gibbo

Thanks for the lingo BTW (Cinema 35mm)!!!

I'm not aware of that being an actual lingo; I just made it up for sake of this conversation.

For whatever it's worth, I tend to use my 18mm (on 1.6 crop factor) quite often. That's partially because I like deep focus, and is sometimes just a logistical choice (shooting in tight quarters).

Personal preference is a good thing. It'd be a shame if we all shot our movies the same way.

[Kholi]

You're confusing yourself by trying to relate everything to full frame, and by not factoring the relationship in distance between film plane, subject, foreground and background.

The latter has the most impact on composition, followed by focal length.

35mm and 50mm could be considered "normals" depending on how you shoot, when concerning Super35. Again, walking camera back a foot and a half or so would have a dramatic impact on composition.

If you're more interested in full frame, then know that the most popular focal length is a 35mm when shooting S35, and if you like shooting a 50mm on Full Frame it may be because it looks like what you've been seeing your entire life... it should have an equivalent AOV of a 35mm prime on an S35 sized sensor.

[jax_rox]

I don't know that i'd call Cinema 35mm a lingo if anything, it'd be Motion Picture 35mm Film.