Undering standing mm = field of view?

[Matthew Rogers]

So, like me, I am sure that many of you are diving into the "cine" world (as far as gear goes) for the first time thanks to the red. Now as I shop for lenses I am confused about what field of view 18-50 really shows me. I looked at my JVC 110u's stock lens tonight and it says that it is 5.5 to 85mm. Well, I know that it's NOT 5.5mm in 35mm terms (considering they make a wider lens for the JVC ProHD line) but I haven't been able to find info on the net that tells me how to convert it to 35mm terms that I can understand.

If someone could find understandable info on how to convert mm's between different size lenses, I think it would make a great sticky.

Thanks,

Matthew

[Poi Boy]

I think it is a .4 or .5 factor so the 18-50 will be about 27 / 75 in 35mm equivalence.
Aloha
-A

[Evin Grant]

My conversion (by the diagonal FOV) from 35mm FF still format to Red 4K is 1.7x
I.E. a 50mm lens on the Red is the same as a 85mm lens on a 35mm still film camera.

Check out this link...
http://www.reduser.net/forum/showthread.php?t=2732
and this one...
http://www.reduser.net/forum/showthread.php?t=1487

[Poi Boy]

Thanks Evin; so as you can see you will definately need something wider to go with your red zooms.
Aloha
-A

[David Mullen ASC]

Since the conversion between 2/3" and 35mm cine is 2.5X, then a 1/3" CCD camera, which is half of 2/3", should be a 5X conversion -- so the equivalent of your 5.5-85mm JVC zoom in 35mm cine terms should be a 27.5-425mm if you want to get a 35mm zoom that matches field of view (in 4K mode on the RED camera). At least in theory.

5.5-85mm -- that's a long zoom...

[Poi Boy]

wouldn't it be nice to get a red zoom tha was the equiv of 27 to 425 !
-A

[David Mullen ASC]

I don't know -- I've always been wary of anything bigger than 10:1 zooms, due to the amount of glass that must be in those 15:1 or 20:1 zooms. In 35mm cine work, I tend to stick to the 5:1 zooms. Partially also because of the size, but I also notice that 5:1 zooms tend to have less breathing problems than 10:1 zooms. For example, the 4:1 Panavision Primo zoom barely breathes but the 11:1 Primo zoom breathes quite a bit.

In B4-mount HD, though, I tend to use the 10:1 zooms a lot.

[Poi Boy]

yes, I understand the pifalls, I was just exclaming in a wishfull thinking sort of way.
Aloha
-A

[Matthew Rogers]

Since the conversion between 2/3" and 35mm cine is 2.5X, then a 1/3" CCD camera, which is half of 2/3", should be a 5X conversion -- so the equivalent of your 5.5-85mm JVC zoom in 35mm cine terms should be a 27.5-425mm if you want to get a 35mm zoom that matches field of view (in 4K mode on the RED camera). At least in theory.

5.5-85mm -- that's a long zoom...

Wow, I didn't realize that that the long end of the 5.5-85 was going to end up being quite that big mm wise. I guess my biggest concern is when I need the extra zoom power while capturing b-roll (oh, excuse me, second unit footage;)) for docs or corporate . Of course, most of the time that I live in the 50mm+ range is for interviews, trying to get the shallow depth of field--which should be about the same in 50-70mm on a 35MM lens.

Thanks,

Matthew

[PaulClements]

David have you ever used the Cooke 28-290mm (10:1) T2.8 (Hannibal). I've only seen it listed for rental at Joe Dunton company. Type "cooke 28-290mm" into Google and it only shows one listing which basically is a thread talking about Red.

[Emanuel A.]

My conversion (by the diagonal FOV) from 35mm FF still format to Red 4K is 1.7x
I.E. a 50mm lens on the Red is the same as a 85mm lens on a 35mm still film camera.

Check out this link...
http://www.reduser.net/forum/showthread.php?t=2732
and this one...
http://www.reduser.net/forum/showthread.php?t=1487More exactly 1.62x according my maths.

[David Mullen ASC]

No, I'm not familar with that Cooke zoom. Probably because I've been renting from Panavision so much these days.

I know that Storaro likes using Technovision zooms (I'm not referring to anamorphic Technovision) that sound similar to the one you mentioned; I think the Technovision zooms are based on Cooke elements.

[Darwin]

Look this does not have to be hard. 50mm lens is 50mm lens. I think where people get confused is when we talk about multplication factors. You must first establish a baseline for your multplication factor. Most here use 35mm full frame still camera's as a baseline.
RED 18-50mm CF zoom
equivalence to 35mm Full frame still.

Nikon DSLR = 1.5 or 50% magnification in the field of view 27-75mm

Canon DSLR = 1.6 or 60% magnification in the field of view 28.8-80mm

RED ONE = 1.7 I think? or 70% magnification in the field of view 30.6-85mm

So if you think 17mm is super wide on a full frame still camera? You have to use a 10mm lens to get the same field of view on a RED ONE. All this means nothing cause at the end of the day, you still have a 18-50mm zoom. If you pick up A DSLR and look through the viewfinder I think you will get a good idea of the FOV for the RED

[Evin Grant]

More exactly 1.62x according my maths.

Actually not, if you are considering the diagonal FOV which is aspect ratio agnostic. You are correct if you are simply factoring for the same 3:2 ratio as 35mm still cameras and DSLRs. But Red is a 16x9 sensor and so there is a little less image top and bottom. Here is the math...

35mm Still
24x24= 576
36x36= 1296
(+) 1872
Square root 1872=43.26= Diagonal dimention/FOV of normal lens

Red 4k
22.2x22.2=492.84
12.6x12.6=158.76
(+) 651.6
Square root 651=25.5=Diagonal

43.26/25.5=1.696

Rounded to 1.7x

[Emanuel A.]

OK Evin, thanks for your care. Let's change numbers!

[our maths]
35mm Still
24x24= 576
36x36= 1296
(+) 1872
Square root 1872=43.26= Diagonal dimention/FOV of normal lens

That's correct! But the ratio is 1:1.5, not 16x9 or 1:1.7(7)

[My maths]
So...

35mm Still @16x9
20.25x20.25= 410.0625
36x36= 1296
(+) 1706.0625
Square root 1706.0625=41.304509= Diagonal dimention/FOV of normal lens @16x9 ratio (same than RED)

Red 4k
22.2x22.2=492.84
12.6x12.6=158.76
(+) 651.6
Square root 651=25.526456=Diagonal

41.304509/25.526456=1.6181058

Rounded to 1.62x

;-)

[Evin Grant]

Ok Emanuel, I see that the diffrence here is in our philosiphy not our math.
I choose to do my calculation based on the original 3:2 aspect ratio of the 35mm still format whereas you prefer to crop the 35mm format to 16:9 before you do your conversion. Both are valid ways of imagining the FOV it just depends on how you're used to working with the formats.
E.

For those reading this scratching your heads...
24mmx36mm (Traditional 3:2 35mm still) conversion to Red 4K 16:9= 1.7x
20.25mmx36mm (3:2 35mm still croped to 16:9) conversion to Red 4k 16:9= 1.62x

[Poi Boy]

For wide sake, I want to believe it is 1.62. and for telephoto I believe it is 1.7.
Aloha
-A

[Emanuel A.]

Ok Emanuel, I see that the diffrence here is in our philosiphy not our math.
I choose to do my calculation based on the original 3:2 aspect ratio of the 35mm still format whereas you prefer to crop the 35mm format to 16:9 before you do your conversion. Both are valid ways of imagining the FOV it just depends on how you're used to working with the formats.
E.Correct Evin. I'm just used to work with still photography in order to go to the shotlist + storyboard. Where I'm used to deal with some air over the frame only 'cause I know there'll be some crop later going to 1:1.85 (or S16 1:1.66 or still 1:1.78 common TV 16x9) or even to 1:2.35/39...my fav format. Otherwise, it will be to compare apples to oranges.

Actually, it has been over this latter ratio that I've been working with. Related to find the right focal length choices on the RED ONE.

Especially, over the wide(st) side. Since I already made my decision on working mainly with PL mount (though some special lenses will run from the Nikon F mount) -- later, I'll be back to the item.

It hasn't been easy to find the right wider options for an affordable price. Unfortunately, the RED 15mm prime will just be available to sell alone (not as part of the set) next year (late 2008).

Even 'cause Stephen has been noticed an unpleasant and undesirable portholing effect on wide end working with open apertures less than T2.8 - T4 stops. This will just mean slower photography shooting wide.

Did you read the thread?

http://www.reduser.net/forum/showthread.php?t=2501

E. :-)

<PS> Interesting point, Poi.

[Emanuel A.]

As matter of fact, I’ve risked and have bought some glass. 16mm too. There was a set of old new glass to sell and a last unit in stock. It was to take or leave it! The last one (the same glass referred by Tim D. –- he's really one of the responsibles for my purchase… Same Tim's supplier/seller but above all, his feedback). And you too, Evin with this thread:

http://www.reduser.net/forum/showthread.php?t=1004

But the lens coverage is the 7.42 x 10.05 mm frame size -> diagonal of 12.492353 (Tim gave me his POV over a slight vignetting, famous on russian glass -- but actually it's nothing more than the difference for the western 16mm 07.49 x 10.26 frame size where the coverage diagonal is 12.703058).

Being the RED @S16 format: 11.1 x 6.3 mm -> 12.763228 as diagonal.

So, apparently, it doesn’t cover. I still can convert the lens for the S16 format into a 12-120 mm focal length but it would cost more than $1K -– I’m not sure that it is worthy for now (before testing @RED).

Also ‘cause using the 1:2.35/39 ratio, as we well know, the coverage will be masked (11.1 x 4.7234042) to a diagonal of 12.063189 –- will the frame size diagonal of 12.492353 larger enough for a full 12.063189 coverage or too much short?

Of course, we can always crop and re-size. That’s why I began this thread here:

http://www.reduser.net/forum/showthread.php?t=2604

Besides, about non standard shooting formats, there’s an interesting open thread from yours on subject related:

http://www.reduser.net/forum/showthread.php?t=1006

EDIT -- My 2k format shooting purpose will just be for 120 fps purposes or only in order to save data at location. Although, like harryclark said in that thread from yours related to the Cooke, a 2x extender can bring any 16mm lens for the 35mm coverage realm. Beyond the coverage issue, any idea about quality losses over the glass there with a 2x extender? Any actual experience on field?

[Stephen Williams]

Beyond the coverage issue, any idea about quality losses over the glass there with a 2x extender? Any actual experience on field?

Hi Emanuel,

2x converters magnify the centre of the image, so any imperfections of the taking lens are increased. Usually you will need to stop down a couple of stops to obtain the best quality with a teleconverter. The cost & quality of the teleconverter make a big difference. I remember the Nikon one's released around the late 1970's were far better than anything available at the time for still photography.

Stephen

[Hugh Miller]

I'm pretty confused now.
Will a 20mm lens (say a 35mm SLR lens) not give the same angle of view when mounted on the RED and using all the chip than when using it as a 35mm film SLR lens?

Is there an equivalent lens of the Canon HJ11 (a 4.7 to 52 or 104mm with the built in 2x extender) for the Red? On the Sony 750 its great, really wide, does great macro (minimum distance of 10mm), especially with the 2x on. It gives a 91 degree image when wide and a 5 degree image when zoomed in. Seems a shame to give up all that to have to keep changing lenses all for 4K.

Is there a lens that can give a 91 degree view for the RED when in 4k mode?

[David Mullen ASC]

A lens between 10mm and 12mm should give you a 91 degree horizontal view on the RED in 4K, or on a 35mm movie camera. Look at this chart on Zeiss UltraPrimes here:
http://www.arri.com/entry/camera.htm

Looks like their 12mm lens has the FOV you're looking for.

[explosive]

My conversion (by the diagonal FOV) from 35mm FF still format to Red 4K is 1.7x
I.E. a 50mm lens on the Red is the same as a 85mm lens on a 35mm still film camera.

Check out this link...
http://www.reduser.net/forum/showthread.php?t=2732
and this one...
http://www.reduser.net/forum/showthread.php?t=1487

FINALLY> THis i understand.

So the 18 on the red zoom is about a 30 in SLR terms? So like another mentioned, one would probably need to get a wide angle lens with the zoom. the zoom seems quite good actually on the Long end. but an additional long(er) zoom may be a helpful addiiton.

I need to learn how to type better whilst camouflaging work... baha

[Don King]

FINALLY> THis i understand.

So the 18 on the red zoom is about a 30 in SLR terms? It is a 29 mm (1.62) in SLR terms.

[David Mullen ASC]

18mm is considered pretty wide-angle in 35mm cine / RED full sensor terms -- "Touch of Evil" and "Amelie", and many of John Frankenheimer's movies, are good examples of the effect of an 18mm. Also consider that most of the wide-angle shots in "Citizen Kane" were made by a 25mm. I rarely even use an 18mm in most of the movies I shoot.

[Emanuel A.]

Thanks David for your input from your own experience on production field (not vain words posted online) -- useful indeed.

[explosive]

It is a 29 mm (1.62) in SLR terms.

No decimal places? :P

[explosive]

18mm is considered pretty wide-angle in 35mm cine / RED full sensor terms -- "Touch of Evil" and "Amelie", and many of John Frankenheimer's movies, are good examples of the effect of an 18mm. Also consider that most of the wide-angle shots in "Citizen Kane" were made by a 25mm. I rarely even use an 18mm in most of the movies I shoot.

David - Wow. I didnt realise citizen Kane's widest was only a 25! Some of those shots looked VERY wide, but i guess that was the illusion they went for with all the matte paintings etc ehey used to make it all look grandoise.

So we really wont need a lens wider than than what the red zoom provides for most shoots?

A touch of Evil had some amazing wide shots. Out of interest, do you know what lens that great crane/tracking shot in the intro used?

One more thing... In your experience Is going wider than 18mm on cine lenses gong to warp the image considerably?

[Andrew Benz]

18mm is considered pretty wide-angle in 35mm cine / RED full sensor terms -- "Touch of Evil" and "Amelie", and many of John Frankenheimer's movies, are good examples of the effect of an 18mm. Also consider that most of the wide-angle shots in "Citizen Kane" were made by a 25mm. I rarely even use an 18mm in most of the movies I shoot.


Thanks David for your input from your own experience on production field (not vain words posted online) -- useful indeed.

I mirror Emanuel's sentiments. Also, I greatly appreciate your posts David and I am really looking forward to meeting you at the LART.

[David Mullen ASC]

The 18mm came out in the 1950's and Welles was a big fan of it, shooting a lot of "Touch of Evil" with it. Also a lot of "I Am Cuba" was shot with an 18mm (and even wider.) Frankenheimer used the 18mm for a lot of "Seven Days in May" and "Seconds" (and some fish-eyed lensed shots in that movie.)

As for "Citizen Kane", 25mm was considered pretty wide-angle back then -- most studio work would have typically used something like a 35mm for wide shots. But remember that the 1.37 Academy format is less cropped than 1.85, so a 25mm looks wider-angle vertically in Academy.

For examples of 12mm or 14mm being used commonly, you'd have to look at Terry Gilliam's latest movies like "Fear and Loathing in Las Vegas" and "Tideland".

Kubrick generally didn't use lenses wider than 18mm except for certain extreme wide-angle camera moves, like a 9.8mm Kinoptic used in that tracking shot thru the music store in "Clockwork Orange" and I think some of the running-thru-the-maze shots in "The Shining".

18mm is pretty much borderline distorted-looking, which is why it is generally the widest-angle used except for stylized effects or simply getting certain shots in tiny spaces.