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-   -   What lens is considered "normal" for HD100? (https://www.dvinfo.net/forum/jvc-gy-hd-series-camera-systems/128473-what-lens-considered-normal-hd100.html)

Jun Sakuma August 22nd, 2008 02:39 AM

What lens is considered "normal" for HD100?
 
I was wondering what lens would be considered "normal" for GY-HD100 as 50mm lens is for 35mm film?

Brian Standing August 22nd, 2008 11:54 AM

Divide the 35mm still focal length by 7 to get the focal length that will give you an equivalent field of view with a 1/3" sensor.

So, a 7mm lens on a 1/3" chip will give you roughly the same field of view as a 50mm lens will on a 35mm still camera. Depth of field, however, will be much deeper with the 7mm.

Jun Sakuma August 22nd, 2008 06:04 PM

Thanks, Brian. So the 5.5~88mm lens that comes with the HD100 is wide, normal and telephoto. Not bad for a stock lens.

Jim Andrada August 22nd, 2008 10:00 PM

Well, I'd call it more of a "sort of a little wider than normal but not a heck of a lot" lens at the widest end of the zoom. Using the divide/multiply by 7 rule it would seem that the 5.5mm is equivalent to a 38mm lens - in other words, sort of wide but not really.

I leave my .7 WA adapter on all the time, otherwise I have trouble getting a wide enough field of view indoors.

Jun Sakuma August 23rd, 2008 12:41 AM

I didn't know that .7 WA adaptor, what brand is it? Can I find it online?
The problem with the stock lens is that I can only get shallow DOF in extreme close-ups. I'm guessing with the WA adaptor I'll be able to frame bigger and maintain the shallow DOF?

Tim Dashwood August 23rd, 2008 12:44 AM

Quote:

Originally Posted by Jun Sakuma (Post 923755)
I didn't know that .7 WA adaptor, what brand is it? Can I find it online?
The problem with the stock lens is that I can only get shallow DOF in extreme close-ups. I'm guessing with the WA adaptor I'll be able to frame bigger and maintain the shallow DOF?

Nope. A wide angle adapter changes the optical characteristics of the lens effectively shortening the focal length, which in turn deepens the depth of field proportionately.

Jim Andrada August 23rd, 2008 01:15 AM

Sorry - I was mistaken. The .7 adapter is on a different camera/lens combinatin

I have the .82 adapter for the standard Fujinon lens on the JVC, so the effective focal length would be around 28mm which is a nice wide angle.

JVC | 0.82x Zoom Through Wide Angle Converter Lens | WCV82SC

Tim Dashwood August 23rd, 2008 01:37 AM

Quote:

Originally Posted by Jim Andrada (Post 923767)
I have the .82 adapter for the standard Fujinon lens on the JVC, so the effective focal length would be around 28mm which is a nice wide angle.

The effective focal length of the .82x adapter on the 5.5x16 lens will be 4.5-72mm.
The equivalent horizontal angle of view of 35mm SLR film would be the same as 31mm-496mm. (using the generally accepted 7x factor.)

Sean Adair August 23rd, 2008 05:56 AM

Quote:

Originally Posted by Jun Sakuma (Post 923755)
I didn't know that .7 WA adaptor, what brand is it? Can I find it online?
The problem with the stock lens is that I can only get shallow DOF in extreme close-ups. I'm guessing with the WA adaptor I'll be able to frame bigger and maintain the shallow DOF?

Jun - you should take a look at this clip from Tim's DVD about the JVC HD, but dealing with the universal DOF, image/sensor size relationship in perhaps the clearest explanation I've ever seen.

Especially since in reading your question again, I think Tim's correct answer here brings you only part way to an answer. The simple answer is that when keeping a subject the same size in your composition, changing lenses and adjusting distance to maintain the same size will bring the effective DOF to the same amount. What changes is the perspective of object and that relation to other things in view. This relationship can give the illusion of shallower depth of field, for instance, by being further back with a more tele lens, you see a narrower view of background, which is less distracting, and if this is more distant than other objects in your normal frame, will have a more "out of focus" background. Often it's more awkward to shoot, and the perspective change is not always appropriate though.

Tom Hardwick August 23rd, 2008 07:19 AM

Quote:

Originally Posted by Tim Dashwood (Post 923772)
The effective focal length of the .82x adapter on the 5.5x16 lens will be 4.5-72mm.
The equivalent horizontal angle of view of 35mm SLR film would be the same as 31mm-496mm.

That's being generous Tim. Sony rates a 4.5 mm focal length on 1"/3 chips as the equivalent of 32.5 mm - so it's a pretty feeble wide-angle.

Tim Dashwood August 23rd, 2008 11:36 AM

Quote:

Originally Posted by Tom Hardwick (Post 923832)
That's being generous Tim. Sony rates a 4.5 mm focal length on 1"/3 chips as the equivalent of 32.5 mm - so it's a pretty feeble wide-angle.

32.5 is probably accurate for JVC too. I used the simple 7x factor. I think the actual ratio is 7.2x.

Jun Sakuma August 23rd, 2008 01:55 PM

Thank you guys, very informative. I saw Tim's clip on DOF, great work.


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