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aimemethe Feb 7, 2010 8:04 PM

Difference between 18-55mm, and 35mm
I have a PENTAX K-X, and on the PENTAX website, it says

"Capture widescreen HD video in full 720p resolution (1280x720) at 24 FPS cinematic frame rate, using any PENTAX 35mm lens"

Now I have the 18-55mm lens that comes with it, and I was wondering what was the difference between that one and the 35mm, and why they mentioned the 35mm specifically?

Thank you

mtngal Feb 7, 2010 8:13 PM

What they are talking about is that the camera can use any Pentax lens made for a 35mm film camera (35mm being the size of the film - as opposed to medium or large format cameras, which use larger film). They aren't talking about focal length. It sure can be confusing, all these mm numbers, if you aren't familiar with the film SLR world.

aimemethe Feb 7, 2010 8:37 PM

Ok, so if I wanted to have the movies look, I would buy a 35mm lens? Not a 35mm adaptor that I can fit on the lens I have right now?

VTphotog Feb 7, 2010 8:50 PM

The lens that came with your camera will work just fine. Use it and enjoy. I would hold off looking for different lenses for a while until you have used the one you have for a while, and develop specific needs. It takes a while before we get to the point where our abilities exceed the limits of our cameras. When we start to concentrate on a segment of photography, we find we need lenses to fit.


aimemethe Feb 7, 2010 10:10 PM

OK, i'll do that, thanks

mtngal Feb 8, 2010 1:16 PM

I completely agree with Brian - use the camera with the kit lens, see what it can do and what (if anything) you want to do that it can't do. You can shoot movies perfectly well with it - it's actually a pretty nice lens.

The news release was saying that you can shoot video using any film lens (substitute the words "Pentax film or digital SLR" for the "Pentax 35mm" in your quote above) - it doesn't require a special 35mm lens.

When you say "movies look" - that's certainly possible with the kit lens, within that particular lens's capabilities. It'll be great for many things, things around the house, kids in the backyard (assuming your backyard isn't huge) etc. However, the lens has limited telephoto capabilities so it wouldn't be good for small song-birds in a tree down the street, or eagles nesting a quarter a mile away. If you want video of things like that, you'd need a different lens.

aimemethe Feb 8, 2010 4:22 PM

Ok, thanks for the advice. And for telephoto capabilities, i have a 50-200mm lens that can go far enough, for what I want to do.

rfortson Feb 12, 2010 2:40 PM

I'd try all your lenses for video. That's one of the advantages of video on a dSLR, the ability to change lenses. If you get a large aperture lens (say the 50mm f/1.4), you can get some need looks in video that used to only come in the theater.

And yeah, that whole "any 35mm lens" statement is confusing. Never really thought about it that way, but I can see why it causes confusion.

aimemethe Feb 12, 2010 7:02 PM

when they say a 35mm lens, they mean a lens for a camera that has actual 35mm film?

mtngal Feb 12, 2010 8:48 PM

Yes, when cameras used film, not all cameras used the same size film. 35 mm was a very common sized film and the term became associated with a class of camera and is often interchangeable with the term SLR. The Pentax dSLR cameras can use any lens Pentax made for their film SLR cameras. For instance, I occasionally use a lens on my Pentax K-7 that I first bought in 1980 for a film SLR camera. I could use that lens to shoot video or still pictures.

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