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-   JVC GY-HM 800 / 700 / 600 Series Camera Systems (https://www.dvinfo.net/forum/jvc-gy-hm-800-700-600-series-camera-systems/)
-   -   HM700 + hz-ca13 + color cast issues? (https://www.dvinfo.net/forum/jvc-gy-hm-800-700-600-series-camera-systems/174167-hm700-hz-ca13-color-cast-issues.html)

Joe Carney April 8th, 2009 09:53 AM

HM700 + hz-ca13 + color cast issues?
 
I read elsewhere that when someone was trying to use the HD 250 with the hz-ca13 they had serious color cast issues with a variety of lenses. Even though there is an in camera fix (color balance top and bottom of frame separately) he felt it defeated the purpose of using the hz-ca13.

Is this still the case with the HM700? Or is is purely an issue with the quality and type of lens you use?

I'm looking to purchase the HM700 body only plus the hz-ca13 and renting some s16mm lenses.

Sean Adair April 8th, 2009 01:07 PM

This topic heading is a bit overly alarmist, when you have an unreferenced and inaccurate statement about another camera.

There is a large body of information on the hz-ca13 in the GY-HD forum. The moderator here and there, Tim Dashwood, has extensive experience with it.

My quick impression is that it is pricey, and only as good as the glass you put in front, but that the result is seamless, compact, and very practical. Especially compared to the troublesome setup, bulky, and unreliable nature of most 35mm DOG adapters. The DOF limiting is not as strong, but significant.

The HD200 series & the HM700 have a menu operation common to many "broadcast" cameras that adjusts "white shade" chromatic inconsistency top to bottom. This is a feature very useful for any video camera that has interchangeable optics. It's a relatively easy adjustment that tunes the camera to that particular optics. 16mm optics will vary tremendously in their quality - but also character.

The most useful scenario is probably renting good modern lenses for DOF limiting, along with possibly improved color and sharpness performance. There may also be some "interesting" lenses valuable for unusual perspectives and looks. I'd imagine in both cases that post processing of the image would be on the cards.

I'm not so convinced that planning to use the camera ONLY in in this configuration is a good choice. Many if not most shooting challenges may be best approached with a dedicated lens designed for the camera. Servo zoom and iris control, ergonomics, and dedicated design for video chips and working resolution are all significant factors.
If the B&H page is correct, there is only a $500 savings without the 17x (which sells there for $3000). That's hard to justify. Personally, if budget was there, for wide angle, I'd definitely want to be rocking the 13x, and only consider primes when DOF was a specific objective. If more budget was there, I'd be moving up the food chain!

Joe Carney April 8th, 2009 01:39 PM

That seemed like a long winded way of saying it's about the glass. I'm familiar with the HD series, just wanted to know how the new HM700 handles this. If the price difference is only 500, then yes I would get it with the 17x, plus the ca13. I'm particularly interested in the Optar Illumina series if they ever start back into production. I was hoping using a set of matched primes would make the situation easier to handle. I'm fully aware using different glass from different mfg will create different issues for each lens.

Shaun Roemich April 8th, 2009 01:47 PM

Quote:

Originally Posted by Sean Adair (Post 1067573)
TThe DOF limiting is not as strong, but significant.

My experience is that DOF is very similar to 2/3" broadcast cameras I've used at the same focal lengths, if that helps.

Tim Dashwood April 8th, 2009 02:47 PM

Quote:

Originally Posted by Shaun Roemich (Post 1067689)
My experience is that DOF is very similar to 2/3" broadcast cameras I've used at the same focal lengths, if that helps.

Yes. 16mm and 2/3" are almost exactly the same size.
Quote:

Originally Posted by Joe Carney (Post 1066958)
I read elsewhere that when someone was trying to use the HD 250 with the hz-ca13 they had serious color cast issues with a variety of lenses. Even though there is an in camera fix (color balance top and bottom of frame separately) he felt it defeated the purpose of using the hz-ca13.

Is this still the case with the HM700? Or is is purely an issue with the quality and type of lens you use?

Adjusting the white shading on the HD200 series is a bit of a chore if you don't have a vectorscope. When using a matched series of lenses things are quite consistent once you set up one of the lenses, but even so every lens is different and may require different profiles. I simple save different scene files for different focal lengths. I've heard of some people seeing white shading differences when adjusting the aperture but I haven't experienced that myself (I try to stick to the F/2.8~F/5.6 range.)

The HM700 has matching top/bottom sensors for setting the white shading. If you watch my "Inside the HM700" (I forget which part...probably #2) I demonstrate how easy it is to set white shading now.
The HM700 can hold 8 scene and 8 picture profiles on each SDHC card so there is more than enough to fine tune each prime lens and simply load the profile as you swap primes.

Sean Adair April 8th, 2009 03:05 PM

Quote:

Originally Posted by Joe Carney (Post 1067686)
That seemed like a long winded way of saying it's about the glass. I'm familiar with the HD series, just wanted to know how the new HM700 handles this. If the price difference is only 500, then yes I would get it with the 17x, plus the ca13. I'm particularly interested in the Optar Illumina series if they ever start back into production. I was hoping using a set of matched primes would make the situation easier to handle. I'm fully aware using different glass from different mfg will create different issues for each lens.

I guess it IS about the glass ;^). I think the most important camera component is the white paint setting. I expect you'd always want to take advantage of the white paint adjustment for each optical setup you make. It will balance the green to magenta transition top to bottom that varies even between the video lenses made for the camera. This is possible on both HD200 series and HM700 (not HD100 series).
Not sure if you've seen this review by our faithful moderator:
http://www.dvinfo.net/prohd/hz-ca13u-review1.php
(caution - might be considered "long winded") and I'm just teasing you here Joe - please don't take offense!

Joe Carney April 8th, 2009 03:26 PM

Quote:

Originally Posted by Sean Adair (Post 1067934)
I guess it IS about the glass ;^). I think the most important camera component is the white paint setting. I expect you'd always want to take advantage of the white paint adjustment for each optical setup you make. It will balance the green to magenta transition top to bottom that varies even between the video lenses made for the camera. This is possible on both HD200 series and HM700 (not HD100 series).
Not sure if you've seen this review by our faithful moderator:
DV Info Net -- JVC HZ-CA13U Cine Optical PL mount Lens Adapter (COPLA) review by Tim Dashwood, Part One
(caution - might be considered "long winded") and I'm just teasing you here Joe - please don't take offense!

None taken, I was being humorous myself if that didn't come through. I've read that review several times.
Tim has provided the answer I'm looking for. The HM700 has features that make it easier to handle this. Making a scene file for each lens isn't a problem if the camera makes it easy to do.


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