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-   -   1/2 lens adapter (https://www.dvinfo.net/forum/jvc-gy-hd-series-camera-systems/46851-1-2-lens-adapter.html)

Louis Quin June 27th, 2005 05:00 PM

1/2 lens adapter
 
When this adapter and 1/2" lenses are used is there a magnification factor? Similar to what the XL2 has when used with the EF adapter (7X I think)?

Barry Green June 27th, 2005 06:45 PM

Yes and no. Yes, in that the field of view won't be the same as what it would have been on a 1/2" camera. But no, in the fact that 1/2" lenses are stated in their millimeter size, so a 10x6.5 lens (meaning, its widest angle is 6.5mm, and its zoom range is 10x) is going to look the same at 6.5mm as the stock lens would at 6.5mm, and it will look the same at 65mm as the stock lens would at 65mm.

In other words, just look at the focal length of the lens, and don't worry about whether it was designed for a 1/2" or 1/3" camera -- a millimeter is a millimeter. However, do keep in mind that the field of view on a 1/3" camera is narrower than it is on a 1/2" camera, so if you're used to the way a lens looks on a 1/2" camera, and then you mount it on a 1/3" camera, it will be more telephoto than it would have been on the 1/2" camera.

The "magnification" factor, between 1/3" and 1/2", is about 1.3x (i.e., a 10mm lens on a 1/3" camera is going to have a field of view about the same as a 13mm lens on a 1/2" camera).

Louis Quin June 28th, 2005 07:36 AM

Thanks very much for the explanation, I thought there had to be some difference, but wasn't sure how much. Those lens listed on the JVC site, "Drawings" page, seem to be SD not HD. I found the S17x6.6BRM Fujinon at B&H ($1699) and it does not apear to be HD, neither does the price. They seem to existing lenses, not new for this camera. Will these be quality enough for HD or only suitible for SD?

Barry Green June 28th, 2005 09:22 AM

Those are SD lenses, yes. Whether they'll prove to be adequate for HD resolution, especially HD resolution at such a higher density (smaller chip) remains to be seen. 1/2" SD lenses perform adequately when they resolve somewhere around 40 line-pairs per millimeter. The JVC needs somewhere around 133 line-pairs per millimeter to adequately resolve the high-def image. Doesn't seem like an SD lens will "cut it", but hey, let's try it and see once the camera comes out...

Steve Gibby June 28th, 2005 11:53 AM

Hey Barry,

As we talked about on another board, I'll bring my HD100, 1/2" to 1/3" step down, and my Fujinon S20x6.4 lens over to your place Las Vegas for us to do some testing on. The 20x6.4 is a more expensive and higher quality SD lens than the Fujinon S17x6.6 lens that Louis mentioned. It should provide a good indication of the max 720p capability of an SD 1/2" lens on the HD100. Should be fun!

One other thing crossed my mind as I was typing this: perhaps JVC's intention in providing a 1/2" to 1/3" stepdown, and including those 1/2" Fujinon and Canon lenses on the HD100 system chart, is simply to create a way for camera users to have top-quality SD lens capability for the SD functions of the camera (480i & 480P). If so, that would be excellent planning on their part for creative flexibility in SD for professional shooters. Could it be that JVC is not intending the 1/2" SD lenses to be used to resolve 720p footage, but merely for use in resolving excellent SD images when shooters are shooting in SD? A thought...

Gibby
www.cut4.tv

Barry Green June 28th, 2005 06:02 PM

Well, and a good thought at that. You're right, it may very well be that the SD lenses may not be adequate for shooting HD, but maybe they were never meant to -- the SD lenses could be targeted strictly at SD shooters -- and that could make for a very capable SD camera indeed! And I am an advocate of saying SD is far from dead -- for many applications, SD will continue to be plenty adequate for quite a while to come. And as an SD camera, it overcomes my only reservations about it (lack of "reality" 60p and HDV artifacts) because it'll offer 60i and even SD 60p...

Basically you'd be getting a DV5000 (although with 1/3" chips, but with 16:9!), plus you'd also have HDV capability... maybe not with the same lens, but you could get 16:9 DV with access to some great lenses, and also HDV with the $13,0000 lens (or the included one)...

Louis Quin June 28th, 2005 09:30 PM

Ya'll are headed in a direction with this thread I was going to ask about. The SD capabilities of this camera, I haven't seen it discused. The specs look like it should do very well. I didn't want to start another camera vs. camera war, but in SD shouldn't this camera out perform the XL2 (with capable operator of course)?

Bill Pryor June 29th, 2005 09:14 AM

I would think this camera, the Z1 and the XL2 would all be very similar in SD. They all three have 16:9 chips and are 1/3" chip cameras. There's not going to be all that much difference. The Sony would be at a slight disadvantage because you can get better lenses for the other two, but with standard cheap lenses, my guess is they'd be equal. Although, the lens you get with the JVC package may be better than the Canon lens you get as standard with the XL2. Or not.

Barry Green June 29th, 2005 10:53 AM

There could be some meaningful differences. The JVC offers, presumably, full 1/3" 16:9 chips. The XL2 offers a smaller 1/3.3 chip. The Z1 is interlaced only, whereas the XL2 and HD100 are both native progressive. The HD100 can do full 480/60p. Then go put a $7,000 lens on it and it should look quite a bit better than the others.

The XL2 has a lot bigger pixels than either the HD100 or the FX1, which should lead to better sensitivity.

You're definitely right, they are all 1/3" cameras and there won't be the stark kind of differences you'd get when comparing a 1/3" camera to a 2/3", but there are enough notable differences there that the footage could be quite noticeably different.

Steve Gibby June 29th, 2005 01:04 PM

Let's analyze the Z1, XL2, and HD100 key SD features:

Z1 - 12x fixed lens, 16x9 CCDs, DVCAM capability, OIS, records in 480i
XL2 - 20x removeable lens, 16x9 CCDs, OIS, records in 480i60, 480p30, 480p24
HD100 - 16x removeable lens, 16x9 CCDs, no OIS, records in 480i60, 480p60, 480p24

I own a Z1 I've used the XL2 and XL1s extensively, and I'll have two HD100's shortly. Keeping in mind the above key SD features for each of the cameras, here's my analysis for their use for various types of SD shooting situations:

Z1: compact form factor for mobile production. 12x fixed lens and 480i a big drawback for indie film production. 480i good for reality look TV. 480p analog SD output from 480i, but not as good as being able to shoot 480p natively. I use the Z1 for SD projects where I need a "run and gun" form factor and native progressive is not the look I'm after. Also, having OIS is nice for those situations. 12x fixed lens is a big drawback for far-away sports, nature, or any long focal length needs. I simply don't use my Z1 for those situations. I also don't use my Z1 when I need good depth of field in the shots. It's extra work to get good depth of field from the Z1. I'm used to getting it easily with detachable professional lenses on my other cameras. A plus factor with the Z1, over the XL2, is being able to also shoot HDV (1080i), which the XL2 can't. The biggest drawback of the Z1's SD capabilities, in comparison to the XL2 and HD100, is the lack of removeable lens and lack of progressive recording capability. The second biggest drawback of the Z1's HD capabilities is the lack of true progressive 24p. In summary, I use my Z1 where I don't need to change lenses, I need a reality look (I don't need progressive recording), and I need more mobility.

XL2: The stock 20x lens is a good lens. The ability to change lenses in certain types of shooting situations is extremely valuable. There's a wide variety of lenses that can be used on the XL2. The 20x, with a 2x extender, makes an excellent setup for long focal length SD needs (sports, nature, etc.). OIS on the 20x can be useful for certain hand held situations. 480i60 (reality look), 480p30 (higher motion subjects in progressive), and 480p24 (indie films, etc.) all have their individual uses. A big drawback of the XL2, as compared to the Z1 and HD100, is that the XL2 has no HDV capability. The XL2 is a relatively big and heavy camera. In true "run and gun" SD situations it becomes unwieldy. When accessorized for indie film production, and used in 24p on a tripod or with a stabilizer system, the XL2 is in it's element.

HD100: The 16x lens should be a good SD lens since Fujinon and JVC claim that it can resolve 720p HDV. It could be better in SD situations than the Canon 20x SD lens on the XL2. With a 2x extender the 16x should be a good long focal length lens for sports, nature, etc. The .8 wide angle converter should make the 16x a decent option for "run and gun" ENG-style situations (balanced with large batteries on the camera). The 13x lens, though pricey, should be a great lens for a wide variety of shorter focal length applications. When accessorized, the HD100 is a little heavy and bulky for situations where extreme mobility is needed. Some of the 1/2" SD lenses that can be used with the HD100 should give it a decided advantage over the XL2 (Fujinon S20x6.4, Canon YH19x6.7). These are $3500 1/2" SD lenses that should have better glass and element structure than the XL2 20x. One decided advantage of the HD100, over the XL2 and Z1, is the HD100's ability to record in 480p60. For shooting high-motion subjects 480p60 beats the heck out of 480i60. If the footage is destined for television, the ability to do slow motion sequences is much better with 480p60, and frame grabs for the project's web site are crisper.

Summary: All three cameras are excellent performers in their designed functions. For real mobile, short focal length, reality-look production, the Z1 would probably be the camera I'd use, accessorized with a wide converter, etc. With the Z1, I'd have the option to shoot it in 1080i and downres in my NLE to 480i60 (DigiBeta, Beta SP) for my SD master, thus giving me the ability to also master the program or project in 1080i for expanded use. For high-action hand held and tripod work, long focal length tripod work requiring interchangeable lenses, or work that required 480p60, the HD100 would be my choice. If I needed to have my production mastered in 720p24 and 480p24, there is only one camera of the three that fits the bill natively - the HD100. Both the XL2 and the HD100 shoot 480p24, but only the HD100 has the option to shoot the eventual 480p24 mastered production in 720p24, thus giving the production "long legs" and scalability for big screen and HD-DVD ancillary revenue options. Will the HD100 or XL2 shoot better looking 480p24 footage? Who knows at this point. With intercgangeable lens capability on both cameras, it will just come down to the quality of lens attached to the camera and the quality of CCDs and camera electronics. If it was 1 1/2" SD lens on the HD100 vs the XL2 with the stock 1/3" 20x lens, my instincts say the HD100 footage would look better. If it was the HD100 with the stock 16x lens vs. the XL2 with the stock 20x lens, who knows? If you put DigiPrimes on the HD100 and Canon long prime lenses on the XL2, who knows? The Z1 suffers from no changeable lens and no 24p or 60p recording in SD, though the 480i60 images are excellent. I think that the ability of the HD100 to also do 720p24 and 480p60 makes it the most versatile of these three cameras. When the HVX200 comes out, the picture will be much more complicated. The HVX will do more resolutions and frame rates than any of these other cameras - but it will suffer just like the Z1 from the lack of interchangeable lenses. I'll also buy an HVX200 for it's added features, and capabilities. If you could make one camera with all the best features of the Z1, XL2, HD100, and HVX200 you'd have an insanely versatile small form factor camera - but you'd also have a camera with a much larger price point.

IMO, of the Z1, XL2, and HD100, the HD100 will probably have more versatility then the others as an SD camcorder. If I was about to spend money on an SD 480p24 camcorder, I'd have to seriously consider the HD100's added 480p60,720p30, and 720p24 capabilities - none of which the XL2 has.

Barry Green June 29th, 2005 02:58 PM

I agree 100% with everything Steve just wrote.

Only thing to add in is that when considering the XL2 vs. the HD100, the XL2 is likely to be a substantially less expensive camera, at least $1500 less, maybe more. It's probably $1500 well spent to get 720/24p and 720/30p, but it is something to factor into the equation.

One other thing the XL2 can do is 480/30p, which the JVC can't. Presuming that you can set a shutter speed of 1/60 on the JVC's 480/60p mode, you could simulate 480/30p.

It remains to be seen how well the HD100 camera performs compared to the others in side-by-side circumstances, but based on the specs I believe Steve's summary is right-on.

Radek Svoboda June 29th, 2005 06:41 PM

Quote:

Originally Posted by Steve Gibby
For high-action hand held and tripod work, long focal length tripod work requiring interchangeable lenses, or work that required 480p60, the HD100 would be my choice.

High action need 50-60 Hz. HD100 only does 30.

Radek

Steve Gibby June 29th, 2005 06:57 PM

Quote:

Originally Posted by Radek Svoboda
High action need 50-60 Hz. HD100 only does 30.

Radek

The discussion was on the SD capabilities of the HD100. In SD, 480p60 will handle high-action subjects extremely well. Your reply is referring to the HDV function of the HD100. Since you brought that up, the 720p30 resolution of the HD100, as per JVC's published tech sheet, is sampled at 720p60 and then frame-doubled and recorded as 720p30. JVC claims their new patented motion smoothing filter will retain the smoothness of the 720p60 sampling, even though the footage is recorded to tape as 720p30. If that works as they claim, high-action subject shooting with the HD100 should be no problem. JVC's tech sheet also states that the motion smoothing filter can be used when the camera is recording in 720p24, thus easing the amount of judder.

Louis Quin June 29th, 2005 09:15 PM

Barry and Steve: Thanks very much for the great explainations and discusion on my question. It helps with understanding the right tool for the job and it's great there are choices for everyone to use.


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