View Full Version : 35mm zoom equivalency - clarification


Bogdan Apetri
July 13th, 2004, 02:42 PM
I spent some time researching the DVX's 35mm zoom equivalency on the forum. The general number is that 4.5mm is about 32mm in the 35mm world (and so on if you go up until 320 at the other end). I have also noted that the Panavision NZ calculator renders these numbers quite a bit different, but not incredibly.

My question is: 35mm still photography or 35mm motion picture cameras? Or is it the same.

Especially since I found out some other numbers, for Standard 35mm Academy Aperture - 4/3 - that renders 4.5mm as an 18.9mm equivalent (up to 189mm at telephoto)

Can somebody say a word on that?
Thanks!

Bogdan

Jeff Donald
July 13th, 2004, 04:35 PM
The film size for 35mm still photography is larger than 35mm motion picture film in it's various incarnations (academy etc.). Exactly what is the size of the lens you have and what format are you using?

Bogdan Apetri
July 14th, 2004, 01:53 AM
Jeff,

As far as I'm concerned, I only want to have an (approximate) equivalency as if I were shooting 35mm film with my DVX100A. Not of great importance, however being a film student, it would be nice to sometimes say: what if I only got 35mm prime lenses and just shoot at that length, move the camera instead of just zooming and zooming and zooming. Of course, DOF it's not the same, but that's a different issue. Just for fun/practice (however arguable).

Since the DVX's chip is 4/3, I assume that I should use the 4/3 Academy ratio of 35mm as an equivalent for what I need, right? In that case, the numbers would be smaller than the 32mm people say it is the correspondent for 35mm still (at the wide end). Probably 18.9 or so? (4.4X multiplication ratio).

But I'm also interested in general, why people want to know the equivalency (for what other reasons). Especially 35mm still (which is aprox 7X the multiplication ratio - so yes, it would make the 35mm still a larger format of course than the 35mm Academy Aperture). Do people want to match photo perspectives in the 35mm world with stills taken from the DVX?

ONE MORE IMPORTANT QUESTION: if I shoot in-camera squeezed or with an anamorphic adaptor, will these equivalence still be valid?

All my assumptions above are true?

Thanks!

Bogdan

Jeff Donald
July 14th, 2004, 02:17 AM
Some people want to know the magnification factor of the choosen focal length. They know how big 200mm is on 35mm still film, but if they use it on a less familiar format, they want a reference.

Charles Papert
July 14th, 2004, 04:25 AM
For those of us who shoot 35mm cine and are generally using prime lenses, selecting a lens for a given shot becomes a combination of art, science taste and voodoo. As an operator I used to make a little game out of anticipating the lens of choice based on my knowledge of the DP or director's sensibilities and discussion of the scene: "so...what do you think..." (in unison) "40mm?". I should point out that I have experienced an interesting type of lens snobbery out there more than once, i.e. the 40mm is "brilliant" but the 35mm is "crap" (must have been a British DP from the sounds of it!), or the 50mm is "boring".

The major difference even when the DV and 35mm cine focal lengths are matched numerically is, of course, the resulting depth of field. Without this I tend to select focal lengths on DV in "zones" rather than exact matches to 35mm primes: full wide, slightly wide, "normal", slightly telephoto, full telephoto. Or perhaps this is just laziness!

Bogdan, your impulse to be thinking in terms of working in this environment is a really good one, and I applaud this notion. It will stand you in good stead if you get to use a Mini35 setup, for instance, or shooting film itself!

Bogdan Apetri
July 14th, 2004, 01:00 PM
Charles,

Thanks for the encouragement. I will be indeed shooting on film also pretty soon, my thesis film in the winter... In the meantime, I also use the PAL DVX100A, it's such a nice camera.

I guess what are you saying is after all correct. Better think in terms of wide, slightly wide and so on all the way to telephoto. After all, we make so many compromises with DV anyway, for the sake of depth of field and all this film look we want (I mean shoot mostly on the telephoto side of the lens and so on).

But it's nice to think in terms of 35mm anyway. By the way: have you shot with the mini35? It should add some extra compromises to the DV format on top of its own. Were you satisfied? I remember one of my cinematography teachers saying it was THE LEAST flexible format he ever worked with.

Take care.

Bogdan Apetri
August 31st, 2004, 04:21 PM
Charles,

I saw you worked with Rose Troche... she was my teacher for one semester at Columbia University.

Bogdan

Charles Papert
August 31st, 2004, 08:59 PM
Bogdan:

Hi, sorry, I never saw your response back in July on this.

Rose Troche--hmmm, enlighten me, what did I work with her on??!

<<Were you satisfied? I remember one of my cinematography teachers saying it was THE LEAST flexible format he ever worked with..>>

I own a Mini35, and absolutely love shooting with it. I have had the opposite experience of your teacher. To me it incorporates a lot of the good stuff of film, with none of the operating costs (i.e. stock, developing, telecine etc). I think it's a blast and looks great.

Here's a link (http://www.dvinfo.net/conf/showthread.php?s=&threadid=31037) to a thread involving a short film I just shot with the setup.

Bogdan Apetri
September 1st, 2004, 07:14 AM
Charles,

Hmmm, sorry, I was wrong. I saw that you worked on the "Go Fish" TV series and I thought it's the movie with the same name, directed by Rose Troche. She also did "Safety of Objects", most recently.

I saw your film, very nice. It's indeed unbelievable that you did it in such a short time! The mini35 looks just great.

Bogdan

PS I like the sax, too. So you're a man of multiple talents. By the way, the Conversation is amazing, indeed. First time to San Francisco for me this winter, first trip to Union Square to see the place of that first zoom shot... I know this movie since I was a kid in Romania.