OT: JVC GY-HD110U HD Interchangeable Lenses

goshep wrote on 3/9/2007, 2:23 PM

I've already posed a similar question regarding interchangeable lenses but now I'm confused again. The GY-HD110U boasts "Interchangeable lenses with standard 1/3-inch bayonet mount" but nowhere can I find any information about additional lenses. Other than the included 16X Fujinon lens, will it accept photographic lenses? Would I once again need a 35mm adapter for photographic lens applications? Someone previously mentioned that Canon (and possibly the JVC) have less light loss when using adapters because the optics are direct (or something like that). I thought I also saw a 1/2" adapter for the JVC. Is it possible to use prime lenses with the JVC?
I've googled quite a bit for answers to these questions but I've found drastically different answers from different sources. What's the final word on interchangeable lenses?

Comments

Patryk Rebisz wrote on 3/9/2007, 3:27 PM

I shot this video with JVC HD110 and 35mm lenses:
link here

You can remove the lens and through an adapter add real 35mm lenses. Without adapter you only replace the lens there is so you don't get much in return.

Indeed JVC and Canon loose less light because you remove the lens so unlike HVX200 and DVX100 you don't have to zoom in with oncamera lens (thus you don't have to loose 2.8 f stop). That said though i think HDV format is crap and totaly unsuitable for any kind of serius color grading/post work. Unlike MiniDV, or DVCPro i can't get back underexposed imgaes because MPEG intruduces horrible amount of large pixels.

goshep wrote on 3/9/2007, 5:08 PM

That's good stuff Patryk. Are any of those other projects shot with the same camera?

Bill Ravens wrote on 3/9/2007, 6:34 PM

You should check the JVC factory website. There, you'll find a range of "standard" zoom lenses at varying cost plus a single wide angle zoom lens. All these lenses are made by fujinon to fit the JVC bayonet mount. Likewise, JVC makes several lens adapters designed to adapt film camera lenses. I should point out to you that these adapters are to adapt professional film lenses, non of which are inexpensive. JVC also has a link to some lens adapter makers, if you wish to adapt Nikon 35mm lenses to your HD100. And, finally, if you wish to mount devices that mimic film DOF, you'll find variants on this concept at RedrockMicro, Letus, P+S Technic, etc. All of these devices are available with any 35mm lens mount you care to purchase.

But, really, you need to go browse the JVC factory website.

goshep wrote on 3/9/2007, 11:35 PM

Thanks Bill. I scoured the website and saw the links and lenses. I guess I'm just confused. Why can I achieve cinemalike DOF with an adapter and still camera lens but not with any of the lenses designed for the HD110? And yes, those lenses are certainly not cheap. Some were considerably more than the price of the camera.

farss wrote on 3/10/2007, 3:19 AM

You can't get the same DOF when the image projected by the lens is smaller, you need to have the lens projecting the same sized image i.e. 35mm. You then use another lens to focus that image onto the sensor.
The advantage with this camera is you can do it using less glass as you can remove the original lens and just use a relay lens.

There's another problem too.

Even IF you could focus the 35mm lense onto the 1/3" sensor you're using only a small part of the lens, something it was never designed for.
Using a 1/2" lens on a 1/3" sensor, not a big deal.
Using a 2/3" lens on a 1/2" sensor, not a big deal.
A 35mm lens onto a 1/3" sensor is pushing it, your focal length is multiplied by the ratio 35mm / 8mm (sorry very rough numbers), so in very rough numbers your 50mm lens is now a 200mm lens!

As you are loosing a heck of a lot of the light coming through the 35mm lense as well you'll loose a few stops.

There's still another problem.
35mm lenses are designed for a much shorter distance between the rear of the lens and the optical plane. The prism in 3 CCD video camera kind of messes with this. Also video lenses are optimised to work with the prism and the sensors as a system. 35mm film lenses aren't.

If you want good glass, rent it, it's way too expensive to buy.
From what I've read 35mm still camera lenses are none too flash for video work, trying to pull focus is a nightmare. Depends on your budget and time I guess.

Bob.

Bill Ravens wrote on 3/10/2007, 5:54 AM

Goshep...

There are several factors that affect DOF. Aperture, distance to the subject, magnification, focal length all have an effect. Since a 35mm lens is designed with a much larger aperture than a 1/3 inch lense, the DOF is much greater for the smaller aperture. The ability to mount a 35mm lens is the way to decrease DOF to film lens COF's. Unfortunately, as Bob points out, the price you pay is extreme magnification of the image.

There are many things to consider when one opts to change a stock lens on a camera. The best you can do, at this stage in your learning process, is to keep asking questions.