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Prime Lenses - 16mm vs 35mm

Published : 12th September 2003


Hi everyone!

I have a rather odd question :

What is the REAL difference between prime lenses made for 16mm versus 35mm?

Look at a PL mount set of Zeiss 16mm Super Speeds...and look at a set of PL mount Zeiss 35mm Super Speeds....

What is the real difference? Why even bother to make 16mm primes? Why not use 35mm instead?

I very, very seldom use primes when shooting 16mm....so my experience is limited to the 'fun' 16mm optics like the 300mm and the 5.7 & 5.9, zooms rule my 16mm world otherwise, but I seldom use zooms on 35mm..I own a full set of Cooke primes and am thinking of using these on my 16SR-2 once it's converted to S-16 with PL mount.

I had an interesting conversation with a 1st and we discussed the 'real' need for 16mm primes versus 35mm primes…

Thoughts?

Cheers,
Jeff Barklage, S.O.C.
http://www.barklage.com
US based DP



Jeff Barklage wrote:

>What is the REAL difference between prime lenses made for 16mm >versus 35mm?

My understanding is that 16mm primes are sharper than a prime designed for 35mm. The reason being the 16mm frame is smaller thus it is enlarged a greater amount requiring a sharper lens to resolve the same detail as compared to 35mm. Less negative area means less film to record your image on so a sharper image is required to make up for that. Which also means the 35mm lens can be a bit softer but still appear sharp as compared to a 16mm lens. Of course the 35mm prime will also project a larger cone of light so it will cover S-16 no problem.

I'm sure other factors come into play like lens depth and aberration correction.
Tom McDonnell
Cameraman/Operator/Editor
New Orleans, La



> What is the REAL difference between prime lenses made for 16mm >versus 35mm?

I read this some time ago, I am not sure where I can find the related drawings.

When engineers design a lens they are forced to make some acknowledgements.

As we all know for most practical purposes it is fair to accept that the operator will frame the most important part of the image not in the dead centre, but in the golden selection of the frame, i.e. about one third from the edge of the frame. Consequently any cine lens should deliver its optimum at this very area. Now if we take a lens designed for 35mm and place it on a 16/S16mm camera, we will be unhappy to discover that the area where this specific lens is giving its best will be exactly at the edge of the frame.

I believe this is the main reason for using 16mm primes. Other parameters may add to this, e.g. it is easier to design a 20mm T2 with better resolution if it is to cover a smaller area....better value for money, also flare might be minimised as well.

Now if you plan to use Cookes via an Arri-S to PL adaptor you might discovered that when the 1st AC changes the direction of focus pulling you might encounter a major shake of the image. This should be due to the lash that the old mount had (and the engineers of Cooke could not do without it since the entire mount barrel rotates together with focus). So before you spend any money... find an adaptor and test.

But of course you could be the owner of a modified PL set of Cookes....so discard the previous paragraph.

Regards

Argyris Theos
DoP
Athens Greece



A lot of people prefer to rent the 35 mm versions. Don't forget the 35 mm still lenses...I have a Contax Zeiss 50mm, same glass, bigger rear element than even the motion picture 35. Soon hopefully I'll get the 35 and 85 ($$$).

How about the Nikon, Canon still lenses adapted to motion pictures?...Also a nice affordable alternative.

John Babl
Miami



Think of the lens as having a cone of light coming in the front and a cone of light coming out the rear. Anytime you gain an advantage in one area you give up something somewhere else. 35mm lenses have to bend the light much further than their 16mm counterparts to cover the format. 16mm lenses don't have to bend the light as much and yes, appear to be a little sharper.

The centre of the lens is the sharpest. 35mm lenses use bigger glass, especially the curved edges so the lenses seem to have more falloff on the sides. 35mm still lenses have to bend light even further to cover the widest of the three formats mentioned. The cone coming out of the rear is much wider to cover that format plus the flange focal depth of a Contax camera is only 38.76mm while the standard Arri is 52mm. Nikon is 46.5mm. While a still lens might look good in telecine it looses its' punch when blown up to the big screen. They are quite good though.

Most Eymos use Nikon's or Cannon's. Cooke S4's will fit on an SR. Cookes have a tremendous amount of resolution.

What is film? Between 50-100 line pairs per millimetre? Depending on the contrast of the scene? How much resolution do you need?

Most Cookes resolve around 200 line pairs per millimetre. It doesn't get much sharper than that.

A 25mm is a 25 mm is a 25mm. The difference is the format area that it covers. Think of the film gate as a window. A 35mm gate is a bigger window. A 16mm gate is a cropped 35mm gate. A "Cowboy" in 35mm will be a much tighter shot in 16mm. This is why a set of 35mm super speeds starts with an 18mm and a set of 16mm super speeds start with a 9.5mm. The 35mm set ends with a 100mm and the 16mm set ends with a 50mm. Same for the zooms. There is an 18-100 Cooke for 35 and a 8-64 Cannon for 16. So if you consider 25mm normal in 35mm. A 12mm should be normal in 16.

Reasons for using S4's, UltraPrimes, SuperSpeeds and Primos?

All these lenses were designed for motion picture use. They cover Super35 and there is no reason to cover much more than that. They all have big lens barrels with big lettering and big gears so you can attach a follow focus and make the AC's job a little easier. Plus they just look cooler than Switars and Contax. And actors love them.
I will admit though that silver Switars are very cool looking. But just where do you put the follow focus?

Tom Jensen
Lens Tech
LA
http://home.earthlink.net/~tomjensen/



>" While a still lens might look good in telecine it looses its' punch when >blown up to the big screen. They are quite good though. Most Eimeo’s >use Nikon's or Canon's."

I must disagree here. Optics are optics.

If a 35mm Nikkor lens can resolve at a high enough level, that is more than enough to produce an excellent image when projected. I have tested many Nikkor lenses using 35mm Kod25 (no longer in production) which will resolve a hell of a lot better than any motion picture film. Not all Nikkors (or anything else for that matter) are the same. Certain lenses stand out as extremely sharp, right to the edges with very little or no flair wide open. They can equal anything comparable in the motion picture dept. (Maybe not Primos or the new S4's, but I've not had a side by side).

Do you think Panavision would use Nikkors if they weren't up to the standard? They'd probably design & make their own. Telephotos are a lot easier to design than wide angles.

Using 35mm lenses on a 16mm camera is a no brainer.

My Nikkor 180mm f2.8, 200mm T2.1 & 300mm T4 are better than the Zeiss glass that I have. Of course this is only my opinion, I could be wrong. But until you put the lens in question on a projector & then shoot film with it, then blow it up, you're just guessing.

Al Satterwhite
DP/LA



Al Satterwhite wrote :

>Optics are optics...but until you put the lens in question on a projector & >then shoot film with it, then blow it up, you're just guessing.

" To a good extent this is true but housings aren't housings and coating just isn't coating."

Tom "now I've lost my punch" Jensen
Lens Tech

As a postscript to this friendly discussion on optics : I would like to say that I think the Zeiss primes (I own a set of Super Speeds) are hands down above anything Nikon can come up with. But since Nikon is not designing a 'matching' set of lenses for use on film cameras, it's not even in the same ballpark. Nikkors are usually used because they are plentiful, relatively inexpensive and sometimes quite adequate. Unfortunately their shorter lenses are not on a par with anything designed by Zeiss or Cooke, plus trying to follow focus them is a nightmare!

The Nikkors I use are very sharp, exhibit very little flair wide open (where I tend to use these optics to the consternation of my 1st) and with added gear rings can be focused quit nicely. I have done a lot of testing to find these optics. Having used most of Nikkor optics over the years I have a pretty good idea which ones are the best (in my opinion).

Everyone has different requirements.

I'm sure that Tom has seen a lot more glass than I have. I totally agree with him on looking at optics critically. I used to shoot my tests on Kodachrome 25 & then loupe it with a 10x magnifier. And then put them on a projector. It's amazing what you can tell about different lenses.



In the early 80s I was involved with Tak-the optical wiz at Panavision on improving the Optimax 3D system that they were trying to bring up to their standards. It had converted Nikon lenses. After doing tests on the MTF (modulation transfer function) machine it was determined that Zeiss lenses from Contax still cameras were far superior. The Nikkors were dropped, and much money was spent purchasing doubles sets of the Zeiss lenses.

I do, however, think that there are some great Nikon lenses, like the 180mm 2.8 (its incredible wide open), the fast 300mm and some others.

Steve Slocomb
shooter/editor
Looking Glass Films
Montana



>…And trying to follow focus them is a nightmare! The Nikkors I use are >very sharp, exhibit very little flair wide open

"Out of curiosity what lenses do you use? Why are they difficult to follow focus?"

The short Nikkors are very difficult to follow focus because they have very few markings on the lens for feet/meters & are not necessarily accurate. The sharpest Nikkors that I have found (usable wide-open with no flair, through testings)

       135mm f2
       180mm f2.8
       200mm f2
       300mm f2
       300mm f4
       400mm f2.8
       500mm f4
       600mm f4
       800mm f5.6 (THE sharpest lens I have ever seen)

......a word of caution. The lenses differ within their focal lengths due to some having ED or no ED glass, updated optical formulas, newer coatings, etc. Testing is required. And the newer AF (auto focus) lenses can exhibit a 'slop' when focusing due to the internal focusing mechanism - they are totally different then the older generation, manual focusing lenses.

There is no still camera zoom lens that I know of that will hold focus during a zoom, so they need to be treated as multi-focal length lenses & refocused every time the focal length is changed (a real challenge if you're using a 50~300mm f4.5 zoom at the 50mm end).

all best,

Al Satterwhite
DP/LA