Jody or someone a question @ HM 650

[Ty Ford]

Hi,

I have an HM 650. My associate has an HM 750 with an optional 17x lens: Fujinon manual focus lens.
Fujinon XT17SX4.5BRM K1

We were expecting (based on comments) that the 650 would actually blow the 750 away. Nope. The picture is much sharper on the 750. One JVC rep offered some tweaks that seemed to have helped.

You'll forgive me, my audio knowledge far outweighs my video knowledge.

Without the tweaks, my associate had to sharpen my footage to +6- in Adobe Premiere and said the blacks were crushed and there was a little noise. He was amazed that the sharpen filter would actually go to 60 without scratching his eyes out. Usually anything over 10 is unusable.

The JVC rep suggested these changes: Detail to +6. Master Black to -3, Knee Auto, Stretch Level 1, Color Gain +3. I shot some footage and when we brought it into Premiere, My associate only had to bump detail to 10 instead of 60. Blacks were up off the line, but still a little crushed and there was some noise in the blacks that were looking at a mottled black backdrop.

He was happy with the changes cause by the above adjustments. My question is, is there room for further improvement? Some way to uncrush the blacks and lower the noise….and anything else.

Thanks in advance for your help.

Regards,

Ty Ford

50 MBps in May! What a nice surprise!

[Jody Arnott]

Afraid I can't help much here, my knowledge when it comes to tweaking the in-camera image settings is limited. I have noticed the same issues myself though.

There are some recommended settings and interesting notes in the EBU assessment here:
https://tech.ebu.ch/docs/tech/tech3335_s08.pdf

I have been using these recommendations for a while, but will try the settings your JVC rep gave you and report back if I notice a difference.

A couple of other tips that I'm sure you will be aware of, but I'll mention them anyway:
Apertures higher than around f5.6 starts to degrade the image. f5.6 seems to be optimal.
Also using -6dB gain helps with noise, but at the expensive of some dynamic range. To access this setting, "extended mode" needs to be enabled in the menu. edit: sorry, maybe not extended mode.. I'll have to check tonight.

I wonder if the 50mbit codec will help with image quality.. I guess we'll find out in May.

[Ty Ford]

I saw that document, but I'm not savvy enough about video specs yet to make proper use of it.

Perhaps someone else will chip in.

Regards,

Ty Ford

[William Hohauser]

First of all, the optional lens on the 750 is much better than the built in lens on the 650. Also the cameras use very different technology for image pickup. CCD vs CMOS. This will affect sharpness and dynamic range. There will be image differences, nothing you can do about that. The two cameras can balance but you might find yourself turning down the sharpness on the 750 to meet with the 650 rather then dialing up the 650.

A decent color chart will go a long way to helping you get the dynamic ranges of the cameras close enough for filming. You will need a very good monitor or waveform monitor to get the levels right. Basically you pick the camera you want the other to resemble and tweak the other camera as close as possible. A resolution chart helps as well.

I work with 750s and 600s frequently enough to know that they can be mixed together successfully without there being a noticeable switch in quality between the cameras.