View Full Version : HDV's Dirty Little Secret


Michael Morlan
December 19th, 2006, 02:09 PM
Howdy all,

I just added an article titled "HDV's Dirty Little Secret" to my website. Can you guess what it is?

http://michael-morlan.net/pages/learning/learning_hdv_dirty_little_secret.htm

(Yes, this is a blatent attempt to get you to visit my site, but also an opportunity to inform.) :-)

Enjoy,

Michael

Greg Boston
December 19th, 2006, 02:22 PM
Well Michael, it's not much of a secret. We've pretty much all figured out that when you jam more pixels onto the same size piece of silicon, something has to give. That something is sensitivity to light. These observations first started when the Sony Z1 came out and was getting compared to the SD PD-170.

-gb-

Chris Hurd
December 19th, 2006, 02:42 PM
Yup, smaller pixels gather less light. Something we've been trying to impress upon our readers here about HD in general for quite awhile now. Sure appreciate the DV Info Net link on your site, though... thanks!

Heath McKnight
December 19th, 2006, 03:06 PM
It's a smaller area with more pixels, like Greg and Chris mention, no big secret. What's a "secret weapon" for Sony is an awesome gain setup which allows clean gain, up to +9 dB, though I usually stay in the +6 range.

heath

Bob Grant
December 19th, 2006, 03:09 PM
This doesn't just apply to HDV, the issue is just as applicable to SD as HD. A 2/3" SD camera will leave a 1/3" camera eating its dust when the going gets tough. The way better optics on a 2/3" camera doesn't hurt either. I've done quite a bit of work with material shot on DigiBeta and then converted to DV (PAL) and I never cease to be amazed at how good DV25 can look.

The bottom line would seem to be that to get the same results as you get from say the PD170 in HDV the imager would need to be 2/3" (in rough numbers), along with optics to match. That 2/3" HD glass costs more than the most expensive HDV camera probably explains why there's nothing offering that level of performance in HDV. However we shouldn't forget that the performance possible from given sized imager has improved over the years as well due to advances in both imager design and the DSP chips behind them.

One could call all this a Dirty Little Secret or An Amazing Miracle, that we can get the images that we do from the current crop of HDV cameras. Still it doesn't hurt to remind people of the underlying principles, oftenly the differences are only apparent when cameras are pushed to their limits.

Perhaps the people who need educating the most are the ones who aren't here, clients today more and more seem to have an issue understanding why we want it shot on expensive cameras when their $500 handycam looks OK, sometimes.

Heath McKnight
December 19th, 2006, 10:57 PM
Well, a $150,000 HD camera vs. a $5,000 HDV camera...no comparison. But I agree that HDV is an amazing tool that many of us use to tell our stories, make our videos, etc. I put my money where my mouth is with my film, which was expertly shot by Jon Fordham on the Z1.

heath

Michael Morlan
December 20th, 2006, 05:12 AM
Yup, the article is written for newbies who, lacking understanding of camera sensitivity, might purchase an HDV camera expecting to be able to light their next epic with Home Depot worklights. (Not that you can't - you just need a lot of them.) ;-)

I'm very pleased with the pictures I've shot with all of the SD, HDV, and HD cameras I shot with and proudly display them on my site and in my reel. But I have a one-ton lighting package and the know-how to do it well. Hopefully, an amateur considering an HDV camera will be just a bit more informed when planning their purchase and productions.

I did find it intriguing that all of the HDV 1/2" cameras I've tested came out at the same ASA. You can't fudge physics that much.

Thanks for the feedback, all.

M