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adys
11-28-2009, 04:51 AM
Hi all

I have been reading about the GH1 a lot in this forum.

I notice the recommendation to shoot 1080 with shutter 60 and 720 with shutter 120, and I have read about NTCS vs PAL, the slow motion etc.

What I could not find is info about shooting with higher shutter speed.

What if I am in a sunny day and shotting with shutter 1000 in 1080?

I will be happy to get some info from your experience, and what are the ways you are dealing with it (combination of aperture, ND recommended combination etc)

Thanks,

Ady.

ROCKMORE
11-28-2009, 05:02 AM
Hi all

I have been reading about the GH1 a lot in this forum.

I notice the recommendation to shoot 1080 with shutter 60 and 720 with shutter 120, and I have read about NTCS vs PAL, the slow motion etc.

What I could not find is info about shooting with higher shutter speed.

What if I am in a sunny day and shotting with shutter 1000 in 1080?

I will be happy to get some info from your experience, and what are the ways you are dealing with it (combination of aperture, ND recommended combination etc)

Thanks,

Ady.

You should do some side by side tests for yourself and you will know right away from first hand experience what things look like at fast shutter speeds.
Get somebody to run down the street and shoot at a 60th sec (50th sec pal) then shoot the same shot at 1000th sec shutter speed. Have a look and you will see the slow shutter speed looks normal and smooth, while the 1000th sec may look like it was shot with a strobe light.

sirk
11-28-2009, 05:03 AM
well of course you won't get the often-desired motion blur if you shoot with shutter 1000. Your video will somehow appear to be chunky, but my experience tells me that the difference is not very dramatic (maybe you should really care about it in a professional production).
I got a Fader-ND Filter which you can adjust from nd2 to nd200 and got some step-up rings for my FD-Glasses which have smaller diameter than the kit lens.
everything works fine :)

adys
11-28-2009, 06:27 AM
well of course you won't get the often-desired motion blur if you shoot with shutter 1000. Your video will somehow appear to be chunky, but my experience tells me that the difference is not very dramatic (maybe you should really care about it in a professional production).
I got a Fader-ND Filter which you can adjust from nd2 to nd200 and got some step-up rings for my FD-Glasses which have smaller diameter than the kit lens.
everything works fine :)


I didn't know about existing of such a thing, Fader ND.

Now that I know, I found this thread.

http://www.dvxuser.com/V6/showthread.php?t=185602&highlight=Fader

Thanks

Ben_B
11-28-2009, 11:19 AM
Many photographers are used to controlling light with a combination of ISO, shutter, and aperture values. When shooting video you're usually just going to be changing aperture, and maybe using ND filters. Changing ISO values within a scene can be distracting and obvious, and changing shutter results in a strange, stuttery image at higher speeds (which can of course be used artistically...look at Saving Private Ryan.) Changing aperture value to cut off light results in a deeper depth of field, and can result in a loss of image resolution at higher F numbers. Therefore, in order to maintain a shallow depth of field or avoid quality degradation in very bright light (sunny, outdoor, daytime) cinematographers have to use ND filters, which cut the amount of light entering the camera independent of the other settings. I usually use a 0.9 filter (3 stops of light...one of the darkest you can get I believe) because I figure if I need to cut light by less than 3 stops I can usually control it with aperture or maybe even shutter (small changes) and still get the image I want in terms of DOF (and using fast glass means it's unlikely to get too dark and I can always open up a bit more than I would have otherwise)...that said these filters are pretty cheap and it's good to have a variety to choose from. I prefer fixed filters over variable because I have heard people have some problems with image quality and hue shifts using variable ND filters.

adys
11-28-2009, 12:04 PM
Many photographers are used to controlling light with a combination of ISO, shutter, and aperture values. When shooting video you're usually just going to be changing aperture, and maybe using ND filters. Changing ISO values within a scene can be distracting and obvious, and changing shutter results in a strange, stuttery image at higher speeds (which can of course be used artistically...look at Saving Private Ryan.) Changing aperture value to cut off light results in a deeper depth of field, and can result in a loss of image resolution at higher F numbers. Therefore, in order to maintain a shallow depth of field or avoid quality degradation in very bright light (sunny, outdoor, daytime) cinematographers have to use ND filters, which cut the amount of light entering the camera independent of the other settings. I usually use a 0.9 filter (3 stops of light...one of the darkest you can get I believe) because I figure if I need to cut light by less than 3 stops I can usually control it with aperture or maybe even shutter (small changes) and still get the image I want in terms of DOF (and using fast glass means it's unlikely to get too dark and I can always open up a bit more than I would have otherwise)...that said these filters are pretty cheap and it's good to have a variety to choose from. I prefer fixed filters over variable because I have heard people have some problems with image quality and hue shifts using variable ND filters.

Thanks Ben.

The problems starts, when I want to shoot with my nikkor 35 f2 wide open, in a sunny day.

In Iso 100 and 60 shutter speed, I need 7 stops ND... and in cloudy day I will need 4-5, and so on.

Do you work with filter combination too - filter on filter?

Martti Ekstrand
11-28-2009, 12:33 PM
I've used two Cokin ND8 (1.8) in broad daylight to get f/2.8 and 1/50. Right now it's dark winter here but I'm gonna look into replacing the Cokins with Formatt HiTech NDs that can go all the way to 3.0! Think I'll get a set that goes from 0.3 to 1.8 or possibly 2.1.

http://www.formatt.co.uk/stills-filters/filters/standard-n-d/stills-filters.aspx

pix2pixels
11-28-2009, 06:59 PM
Martti,
I read on the Formatt website that the High Density neutral filters might not be suitable for CMOS based cameras. Did you have any issues with the 2x1.8 stack?

Martti Ekstrand
11-28-2009, 11:59 PM
Well the Cokin NDs come with a pinkish look built-in so if there's any IR contamination going on as well it's hard to judge. That's why I'll flip to HiTech when the light comes back to Sweden*, wish I'd know they existed before I got the Cokins. I've so far been able to fix that with colour correction. Look at the commercial in my sig, the daylight scene is done with 2 x ND8.

Unfortunately I haven't found any retailer here in Sweden stocking a Hot Mirror / IR cut filter so I can't say if and how much GH1 is affected by this. They are quite expensive so I don't want to ship in one only to find it doesn't do much. Got a still unanswered thread about this in the hardware section.

http://www.dvxuser.com/V6/showthread.php?t=177055

*Or possibly a real matte box and glass filters