1/25th shutter at 25p: disadvantages? at DVinfo.net

Reese Leysen · July 10th, 2007, 05:13 AM

I used to shoot 1/25 for a while on DV interlaced but stopped when I realized what a drop in resolution it caused. Too bad because other than that, I thought it made for a very cinematic form of motion clarity.

Now I'm about to buy an HV20 (PAL) which can shoot at 25p and I wonder, can I now shoot 1/25 without disadvantages?

And I also read somewhere that that 1/25 shutter is actually NOT AT ALL recommended to get a film-look because the motion clarity is nothing like film at all. I don't really see this.

Anyone care to comment?

Dan Burnap · July 10th, 2007, 08:01 AM

Hi Reese, I shot 1/25 on my DVC30 which although not progressive gave a great style and only with motion blur if the action was really moving. After I got my DVX100 I was planning to shoot my next event 25p at 1/25, 1/25 of course helps in low light too. I did some test footage in broad daylight at 25p 1/25. The amount of motion blue was massive, even in slight movements, even a slow pan would have been un-useable. If your subject is static I cant see a problem but if it's moving I'd ramp up to 1/50.

Marcus Marchesseault · July 10th, 2007, 04:39 PM

Remember that an interlaced camera loses resolution and framerate when shooting at 1/25 (PAL) or 1/30 (NTSC) shutter speeds. Motion blur and 15/12.5fps will not look so great. It's okay if you don't move the camera, but the stutter is just too much at 15fps. A progressive camera will have motion blur, but the higher framerate makes everything look better. If you really need the extra exposure and don't mind extra motion blur, the slow shutter on a progressive camera can be very helpful (assuming the HV20 truly shoots progressive).

Johan Forssblad · July 12th, 2007, 02:30 PM

Hello Reese,

Why should 1/25 sec. exposure time look so cinematic? A real film camera shooting 25 fps has a much shorter exposure time than 1/25 s. Closer to 1/50 s if I know right to allow for film transport. Greetings from Sweden! /Johan

Reese Leysen · July 12th, 2007, 03:37 PM

Well, I don't know actually... But for some reason 1/25 looked fantastic on my old PDX10P DV cam... But now that I see some 1/48 HDV progressive footage, I must reconsider. The HV20 doing 1/48 in 24p looks so close to film it's amazing.

Dylan Pank · July 15th, 2007, 03:29 PM

Quote:

Originally Posted by Reese Leysen

Well, I don't know actually... But for some reason 1/25 looked fantastic on my old PDX10P DV cam... But now that I see some 1/48 HDV progressive footage, I must reconsider. The HV20 doing 1/48 in 24p looks so close to film it's amazing.

It will because if you shoot 1/48th at 24p (or 1/50 at 25p) you're recreating the motion blur of film pretty closely. 1/24 at 24fps is impossible on film (maybe it can be simulated with CG frame morphing or something)

However for low light some movies shot in HD do use 1/24 in lowlight situations (Apocalypto and Collateral that I know). Personally I never liked 1/24 and when it pops up in the those films, it does look a great deal more videoish to me than 1/48th @24p. However if push came to shove it's great for getting that extra stop in a tricky lighty situation.However I had some students kept alternating 1/25 with 50i and the back and forth switching (sometimes between the two in the same scene!) was pretty distracting.

July 10th, 2007, 05:13 AM	#1
Reese Leysen Regular Crew Join Date: Feb 2007 Location: Belgium Posts: 114	1/25th shutter at 25p: disadvantages? I used to shoot 1/25 for a while on DV interlaced but stopped when I realized what a drop in resolution it caused. Too bad because other than that, I thought it made for a very cinematic form of motion clarity. Now I'm about to buy an HV20 (PAL) which can shoot at 25p and I wonder, can I now shoot 1/25 without disadvantages? And I also read somewhere that that 1/25 shutter is actually NOT AT ALL recommended to get a film-look because the motion clarity is nothing like film at all. I don't really see this. Anyone care to comment?

July 10th, 2007, 08:01 AM	#2
Dan Burnap Major Player Join Date: Oct 2005 Location: Rio de Janeiro Posts: 335	Hi Reese, I shot 1/25 on my DVC30 which although not progressive gave a great style and only with motion blur if the action was really moving. After I got my DVX100 I was planning to shoot my next event 25p at 1/25, 1/25 of course helps in low light too. I did some test footage in broad daylight at 25p 1/25. The amount of motion blue was massive, even in slight movements, even a slow pan would have been un-useable. If your subject is static I cant see a problem but if it's moving I'd ramp up to 1/50.

July 10th, 2007, 04:39 PM	#3
Marcus Marchesseault Trustee Join Date: Nov 2005 Location: Honolulu, HI Posts: 1,961	Remember that an interlaced camera loses resolution and framerate when shooting at 1/25 (PAL) or 1/30 (NTSC) shutter speeds. Motion blur and 15/12.5fps will not look so great. It's okay if you don't move the camera, but the stutter is just too much at 15fps. A progressive camera will have motion blur, but the higher framerate makes everything look better. If you really need the extra exposure and don't mind extra motion blur, the slow shutter on a progressive camera can be very helpful (assuming the HV20 truly shoots progressive).

July 12th, 2007, 02:30 PM	#4
Johan Forssblad Major Player Join Date: Nov 2005 Location: Vittsjö, SKÅNE, SWEDEN Posts: 266	Hello Reese, Why should 1/25 sec. exposure time look so cinematic? A real film camera shooting 25 fps has a much shorter exposure time than 1/25 s. Closer to 1/50 s if I know right to allow for film transport. Greetings from Sweden! /Johan

July 12th, 2007, 03:37 PM	#5
Reese Leysen Regular Crew Join Date: Feb 2007 Location: Belgium Posts: 114	Well, I don't know actually... But for some reason 1/25 looked fantastic on my old PDX10P DV cam... But now that I see some 1/48 HDV progressive footage, I must reconsider. The HV20 doing 1/48 in 24p looks so close to film it's amazing.