[ronaldkwok]

I have posted the results of my flicker test in my Blog below, especially for Sergei who may want to give his comments and interpretation. Seems that using a shutter speed of 1/100 gives the least flicker.

[boldandfunny]

Thanks Ronald
Brilliant test! Best on the WEB! That's URL for other people:
My Video Journey with Sanyo Xacti Camcorder, the VPC HD2000 to be exact
Look for December 2009 post. This has a Youtube fluorescent light test video taken at different shutter speeds.

IMHO the test basically confirmed all my speculations in this thread above (I am blushing a bit actually ).

Note: This test only applies to old-style fluorescent bulbs (usually a straight tube) and does not apply to compact modern screw-in low energy fluorescent bulbs which do not have any flicker (or very little at frequency 40-50 KHz - which for our purpose and shutter speed means none).

For 30P as Ronald says in his blog say we have:

1)Shutter speed 1/30s = 33.33 ms - as expected we sometimes have just 3 flashes and sometimes 3 and a bit of 4th flash. Very little flicker (I expected about 5% difference between brightest and darkest frames - see my posts above for details). Still a bit annoying, but probably usable.
I can bet that 1/50s would not have any flicker (the same as 1/100s) - the same as normal PAL camcorder. Sanyo - can you hear me? Please include 1/50s shutter for us in 50Hz contries! Or better still make a 25/50 fps version!

2)1/60=16.66 ms is quit bad. We get 1.66 flashes on average which probably means about almost 2 flashes for brightest frames and as low as 1 flash (and 2 dark bits on both sides of it) for darkest frames.

3)1/100s=10 ms is exactly one period of flash frequency. As we all know, an integral of a any periodical function taken over a period is constant whenever we start. There is no flicker (the same applies to 1/50 sec - exactly 2 periods).

4)1/125s=8ms is getting worse again. It is now shorter then period so depending when shutter is open we can get all of the dark gap or may be none at all. It depends on how long dark gap between flashes is. If flash is very short (say less or equal 2 msec) then there is a possibility of missing it altogether now (as gap is 8 msec we can only have shutter open during the gap!).

5)and 1/250=4ms, 1/500=2ms and 1/1000=1ms are definltely gettting worse - for the same reason as 1/125 - a frame can actually be shooting darkness.

6)Actually at 1/250 - 1/1000s we can definitely see the 'Partial exposure' effect decribed in the article CMOS Rolling Shutter Rogs posted earlier.
You can see them as horizontal brighter/darker areas on the picture.
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As for practical implications for shooting indoor sports (which is what I will be doing 95% of the time) I am not quit sure what to do now.
I really like ability to shoot 60P or 30P, but I at the moment I am only guaranteed a single shutter speed avalilable to me (1/100s) to not have any flicker.
On the other hand there are other factors involved which may make flicker less or even result in none at all in an average hall:

1)Sometimes bulbs are paired with a shift in flashes between the 2 bulbs arranged electronically - this is a safety feature as well - against stroboscopic effect (not the case in Ronald's video I beleive as results would not match my guesses so nicely if it was).

2)In big(ish) halls lights would normally be running from all 3 phases of the AC mains, I beleive - if anyone is an electrician here - could you please confirm this?
This would result in flash frequency trippled to 300Hz=3.33 ms so that shutters of 1/30=33.33 ms and 1/60 = 16.66 msec will be all over a few whole periods of this frequency. The only flicker which will be still noticeable (may be not) would be the fact that different bulbs will be at different points of the ceiling. This means that shadows and bright spots will be moving around a bit as relative moment of shutter opening is moving around (say relative to phase A sin wave).

3)Newer fluorescent bulbs may be using High frequency (40KHz) AC generated internally and have no flicker at all (this wiki articale implies so):
Fluorescent lamp - Wikipedia, the free encyclopedia

The 3 points above are probably relevant to the second test video Ronald was going to post today (there was a problem - I am really looking forward to seeing that!) taken in a mall.
This should be similar to an averags sport hall I'd guess (well some school halls may be much worse though ).

Thanks again Ronald - you are a star!

Sergei Glasgow UK

[boldandfunny]

Originally Posted by smichelsen

I have shot and posted that 1080p60 video with a car passing by, as requested. I also shot three similar scenes - fast handheld pans following a vehicle, in 30p, 60i and 60p. Enjoy.
Sanyo VPC-FH1 test footage

Thanks a lot Steve! Those are best test shots I found anywhere - they allow to compare almost identical shots at different modes.

As I am looking to shoot basketball I am really impresed tih quality of 60P panning shots. Very little panning blur which is so obvious in 60i.

I was also impressed by 30P shot - very little blur as well. This may be a good option for basketball too.

Thanks again
Sergei

[ronaldkwok]

Originally Posted by boldandfunny

Thanks Ronald
Brilliant test! Best on the WEB! That's URL for other people:
My Video Journey with Sanyo Xacti Camcorder, the VPC HD2000 to be exact
Look for December 2009 post. This has a Youtube fluorescent light test video taken at different shutter speeds.

IMHO the test basically confirmed all my speculations in this thread above (I am blushing a bit actually ).

Sergei Glasgow UK

Thanks for all the superlatives, I'm blushing more than you!

And thanks for the interpretation, not sure if I understood all of it. Anyway, the second video is now on at Vimeo here
A X'mas Medley - Sanyo HD2000 on Vimeo
The last song is complete in the original but the last few seconds were truncated during the upload (by Vimeo??), not sure why.

For your purpose, you may want to look at another video here Kids Are Fun - Sanyo HD2000 indoor on Vimeo that was taken at an indoor sports hall where the lighting may be similar to a basketball venue. No flicker here but they may not be using any fluorescent tubes and only the energy saving type used or the shutter speed was not too fast; shot in auto mode.

I do not remember seeing any flickers in my indoor videos previously but then earlier I never know about this flickering issue. Maybe if I look hard enough, it may be there but definitely not bad enough to be noticed casually and be distracting.

Merry Christmas to all.

[toffeemrd]

Hope you all had a good Christmas

Thanks for the informative posts; I am learning more each day about camcorders and what all those great marketing claims companies make actually mean!

I have narrowed choices to Sony CX105 and the Sanyo's (not sure which one though) and as it seems the SD cards for the Sony are more money I am getting closer to purchasing the Sanyo with my Xmas and hard earned money!

Please can I ask you owners who have given me (and others I am sure) a great insight to these camcorders, how do you find the shakiness on videos for the HD2000 and the FH1, does the camcorder actually help correct any shake of hand? Also, if you can answer this, will the Sony also suffer flickering with the lights?

Thanks again for your time on this thread and the videos uploaded/written blog as these are great in helping us less knowledgeable individuals more aware of what their investment is going towards

[boldandfunny]

Tofeemrd
I think any camcorder which has 1/25s, 1/33.3s (never seen one), 1/50s and/or 1/100s shutter speed will not suffer the 50Hz flicker under fluorescent light. This is true for any (25/30/50/60 fps).

If you buy an UK (EU) version of this Sony (e.g. 50i version) it (AFAIK) does 50 fps and default shutter speed is 1/50 s (I think it only works in 50i mode). This will not have any flicker under 50Hz fluorescent lightning. I had a Sony HDD version of these camcorder and it was fine in default settings (it does not have manuall setting for shutter speed though). I did some shooting in an office environment under a single fluorescent tube and there was no flicker.
I would not buy a 60i version of this camcorder for use in UK though (50Hz) as default shutter will be 1/60 sec and this will result in a lot of flicker. As you will not be able to set 1/100s shutter manually this means it is unusable under flourescent light at all.
Hope this helps
2)Don't know much about image stabilization on HD2000. Using a tripod will definetley help. Also I think without using zoom footage will probably be quit usable. If you need to use zoom (more then 2x I'd say) a lot then you'd need a tripod (IMHO)


Sergei.

[boldandfunny]

Hi,
just thought I'd update this thread with my real life experience with 60fps camcorder (Sanyo HD2000) flicker problem in UK.

Basically so far I did some indoor basketball shooting in 2 school halls here in Glasgow UK and discovered the following:

1)First school hall - no flicker at all with any shutter speed. They must be using modern fluorescent lights. These one is a private school so the lights must have been upgraded a few years ago or something. Lights are almost white.

2)Second school hall -a public school - different lighting (yellowish, round light fixtures with a big bulb). Got very little, but noticeable flicker at 1/100 sec shutter speed - which is contrary to what I expected (I expected none!!!).
I guess these lights must have an asymmetry in light production between positive and negative half-wave. Actually flicker (on the footage and viewfinder LCD) was only noticeable in one end of the hall but not another.
Note that to the naked eye there was no flicker in this hall.
I tried using 1/30 sec shutter (with 30P) but flicker was more noticeable and movement was not as smooth as at 60P or 60i, so I was back to 60P 1/100 sec quickly.
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Well, so much for my theory that 1/100 sec shutter should produce no flicker at all!

I am keeping my HD2000 - I guess I could have returned it on the ground of this flicker, but I hope that this hall no 2 was the worst case I will ever have and it was not too bad at all - I mean while I watched the game I forgot about it very quickly.

Just for your information guys.
Sergei