ADJ Dotz Par Light

Bob Richardson · September 3rd, 2014, 03:20 PM

This is a follow-up to my test last week of the ADJ "Mega TriPar Profile" fixture, which exhibited flicker on-camera when any of the RGB channels were dimmed below 100%.

Original post:
http://www.dvinfo.net/forum/photon-m...cker-test.html

Now I've acquired the newer, brighter "Dotz Par" fixture, which is advertised as being "Flicker Free (No Flicker on Camera)". While there is still a subtle, undulating flicker under certain conditions (and it can be made worse using the included beam narrowing lens/filter), it is a significant improvement over the previous fixture. Whether it is good enough for your production is something you'll have to evaluate, the problem is not invisible and it could be noticeable in a final product.

(DOWNLOAD THE ORIGINAL or watch in HD 1080P to best see the effect being tested -- the extra compression via Vimeo masks much of the flicker as macroblocking.)

Andrew Smith · September 14th, 2014, 04:48 AM

The originally uploaded file is not available for download. Had you uploaded via Dropbox?

Can definitely see the flickering effect, though.

Andrew

Bob Richardson · September 14th, 2014, 04:55 PM

Thanks for pointing that out... I see that the original file isn't available via Vimeo. Apparently if it's over a certain size (I used a very high bitrate to show the effect), they delete it after the initial conversion. Glad you could see the effect anyway. It is partially obscured by compression.

Andrew Smith · September 14th, 2014, 05:34 PM

What data rate are you encoding at?

Andrew

Bob Richardson · September 14th, 2014, 05:41 PM

It averages about 25Mbits/sec H264. Exorbitant for web video, I know, but it was the only way to get the re-compressed version on Vimeo to really show what was going on, and uploading at lower bitrates sometimes caused Vimeo to disallow the 1080P option. The original camera recordings are 24MBit AVCHD so in that sense it's not too far off, and of course a ProRes export at up to 100MBit shows everything quite clearly. But in any case I'm glad the point got across with the final result.

Nick Piegari · April 4th, 2015, 05:25 PM

This is very informative. I had my eye on the older unit, but I've decided against them now that I can see how bad the flicker is. Thanks!

I'm trying to get a feel for how bright these are. Are you using them alongside "real" video lights, or just room lighting? Any chance you can stick a light meter in front of one of them at full white? I want to see if they could be used as a background wash alongside Litepanels-style lights. Alas, the manual provides no sort of brightness rating.

(I hope I'm not being too necromancy-ish; I suppose this thread is a little old at this point.)

September 3rd, 2014, 03:20 PM	#1
Bob Richardson Regular Crew Join Date: Mar 2009 Location: Portland, OR Posts: 178	ADJ Dotz Par Light - Camera Flicker Test This is a follow-up to my test last week of the ADJ "Mega TriPar Profile" fixture, which exhibited flicker on-camera when any of the RGB channels were dimmed below 100%. Original post: http://www.dvinfo.net/forum/photon-m...cker-test.html Now I've acquired the newer, brighter "Dotz Par" fixture, which is advertised as being "Flicker Free (No Flicker on Camera)". While there is still a subtle, undulating flicker under certain conditions (and it can be made worse using the included beam narrowing lens/filter), it is a significant improvement over the previous fixture. Whether it is good enough for your production is something you'll have to evaluate, the problem is not invisible and it could be noticeable in a final product. ADJ Dotz Par Light - Camera Flicker Test on Vimeo (DOWNLOAD THE ORIGINAL or watch in HD 1080P to best see the effect being tested -- the extra compression via Vimeo masks much of the flicker as macroblocking.)

September 14th, 2014, 04:48 AM	#2
Andrew Smith Equal Opportunity Offender Join Date: Feb 2009 Location: Brisbane, Australia Posts: 3,065	Re: ADJ Dotz Par Light - Camera Flicker Test The originally uploaded file is not available for download. Had you uploaded via Dropbox? Can definitely see the flickering effect, though. Andrew

September 14th, 2014, 04:55 PM	#3
Bob Richardson Regular Crew Join Date: Mar 2009 Location: Portland, OR Posts: 178	Re: ADJ Dotz Par Light - Camera Flicker Test Thanks for pointing that out... I see that the original file isn't available via Vimeo. Apparently if it's over a certain size (I used a very high bitrate to show the effect), they delete it after the initial conversion. Glad you could see the effect anyway. It is partially obscured by compression.

September 14th, 2014, 05:34 PM	#4
Andrew Smith Equal Opportunity Offender Join Date: Feb 2009 Location: Brisbane, Australia Posts: 3,065	Re: ADJ Dotz Par Light - Camera Flicker Test What data rate are you encoding at? Andrew

September 14th, 2014, 05:41 PM	#5
Bob Richardson Regular Crew Join Date: Mar 2009 Location: Portland, OR Posts: 178	Re: ADJ Dotz Par Light - Camera Flicker Test It averages about 25Mbits/sec H264. Exorbitant for web video, I know, but it was the only way to get the re-compressed version on Vimeo to really show what was going on, and uploading at lower bitrates sometimes caused Vimeo to disallow the 1080P option. The original camera recordings are 24MBit AVCHD so in that sense it's not too far off, and of course a ProRes export at up to 100MBit shows everything quite clearly. But in any case I'm glad the point got across with the final result.

April 4th, 2015, 05:25 PM	#6
Nick Piegari New Boot Join Date: Nov 2013 Location: DC Posts: 8	Re: ADJ Dotz Par Light - Camera Flicker Test This is very informative. I had my eye on the older unit, but I've decided against them now that I can see how bad the flicker is. Thanks! I'm trying to get a feel for how bright these are. Are you using them alongside "real" video lights, or just room lighting? Any chance you can stick a light meter in front of one of them at full white? I want to see if they could be used as a background wash alongside Litepanels-style lights. Alas, the manual provides no sort of brightness rating. (I hope I'm not being too necromancy-ish; I suppose this thread is a little old at this point.)