some low light test footage at DVinfo.net

Henry Cho · November 6th, 2006, 07:05 PM

here is some footage i just shot from my rooftop. camera settings throughout all the clips is: manual mode, 24f, shutter at 1/24, black "stretch", coring "3", noise reduction 1 "low".

the first set of clips is a slow tilt up to the manhattan skyline. the first clip was shot -3dB gain with the iris wide open (f3.2) in a pure night sky environment (i.e., it was dark out). the second clip is the same shot at +12dB gain. i actually closed the iris down a bit to f4 to prevent the lights from blowing out too much. i know, not very scientific, but you will get some idea of what's happening.

(these files are approximately 120MB each. download to your computer, and remove the "x" at the end of the filename.)
http://www.downwiththefuture.com/a1/...e_f3_-3dB.mpgx
http://www.downwiththefuture.com/a1/...e_f4_12dB.mpgx

the second set of clips is the camera pointed at a traffic intersection about 7 blocks away (gotta love that 20x zoom). not as pretty, but from a comparative standpoint, this is probably a better look at the low light ability of the a1. in both clips, the iris was left wide open, so all you'll be seeing is the change in gain, from -3dB to +12dB).

(these files are approximately 35MB each. download to your computer, and remove the "x" at the end of the filename.)
http://www.downwiththefuture.com/a1/...ight_-3dB.mpgx
http://www.downwiththefuture.com/a1/...ight_12dB.mpgx

i really like the a1, and i think it holds up pretty well at the higher gain settings. you could probably take the noise down further by stepping up the coring a bit and adding some further noise reduction via the NR2 setting.

i can only leave these clips up for a couple of days.

Matthew Nayman · November 6th, 2006, 07:14 PM

Hey Henry, glad to see you're feeling better.

Clips are downloading.....

BTW, why does everyone say 3.2 is wide open? I know zoomed it is, but wide angle, the lens does 1.6... if my cinema - math is right, that is... 1->2 = 1 stop... 2->2.8 = 1 stop 2.8->4 =1 stop... you can open the camera up nearly another 3 full stops, amore than quadrupling the light... (each 1 fstop doubles available light)

So, I would assume with an M2 on the front, zoomed in enough, you have 2.2 on the camera, plus 1 stop from the GG and then 1.4 from a fast lens.... want to try it out! Hurry up vistek.

Matthew Nayman · November 6th, 2006, 07:38 PM

Had a look at the clips... Ithink the low light looks amazing man...

that shot of the intersection at -3 is unbelieveable... thats at -3db with a 1/24 shutter right? so at 0db witr a 1/48 will look as good...

Pete Bauer · November 6th, 2006, 07:51 PM

I think that's pretty close. A doubling of light passing the aperture results from an increase in radius of the aperture of the square root of 2, which is 1.414. So:

f1.6 x 1.414 = f2.26
f2.26 x 1.414 = f3.2

Of course, mechanical shutters aren't perfectly round and f-stops are rounded-off numbers, but this would be a mathematical approximation of what's really happening in the camera...but close. So call it two stops, or four times the light.

EDIT: Just finished downloading and taking a quick look at the clips. Thanks for posting them and their settings, Henry. BTW, most impressive job of smooth tilt on the cityscape clips! You must have both a good tripod and a really steady hand!

Henry Cho · November 6th, 2006, 08:02 PM

thanks matthew... not 100% but getting there. i think the itch to take the new camera out for a whirl is expediting my recovery :).

i apologize in advance for the 120MB files. in retrospect, a similar, or better, test could have been done at a fraction of the filesize.

Richard Zlamany · November 6th, 2006, 08:49 PM

It looks good, but is the 2nd set of clips out of focus?

Henry Cho · November 6th, 2006, 09:24 PM

yeah... i was at the long end of the zoom, and had my tripod situated in a wierd spot on the roof, on a bed of stones, so i could see the street. when i shot it, i thought it was set :).

Evan C. King · November 7th, 2006, 01:25 AM

Taffic intersection at -3db. Wow. That kinda low light is all I'm looking for. Sorry sony Henry just won this battle for me.

I'm gonna get this within a month, now I know it can do everything I want from it.

Daniel Boswell · November 7th, 2006, 01:30 AM

Quote:

Originally Posted by Henry Cho

here is some footage i just shot from my rooftop. camera settings throughout all the clips is: manual mode, 24f, shutter at 1/24, black "stretch", coring "3", noise reduction 1 "low".

the first set of clips is a slow tilt up to the manhattan skyline. the first clip was shot -3dB gain with the iris wide open (f3.2) in a pure night sky environment (i.e., it was dark out). the second clip is the same shot at +12dB gain. i actually closed the iris down a bit to f4 to prevent the lights from blowing out too much. i know, not very scientific, but you will get some idea of what's happening.

(these files are approximately 120MB each. download to your computer, and remove the "x" at the end of the filename.)
http://www.downwiththefuture.com/a1/...e_f3_-3dB.mpgx
http://www.downwiththefuture.com/a1/...e_f4_12dB.mpgx

the second set of clips is the camera pointed at a traffic intersection about 7 blocks away (gotta love that 20x zoom). not as pretty, but from a comparative standpoint, this is probably a better look at the low light ability of the a1. in both clips, the iris was left wide open, so all you'll be seeing is the change in gain, from -3dB to +12dB).

(these files are approximately 35MB each. download to your computer, and remove the "x" at the end of the filename.)
http://www.downwiththefuture.com/a1/...ight_-3dB.mpgx
http://www.downwiththefuture.com/a1/...ight_12dB.mpgx

i really like the a1, and i think it holds up pretty well at the higher gain settings. you could probably take the noise down further by stepping up the coring a bit and adding some further noise reduction via the NR2 setting.

i can only leave these clips up for a couple of days.

cant get them to play in QT. I changed the suffix to mpeg and all i get is a white screen. VLC wouldnt do it either.

Jack Jenkins · November 7th, 2006, 03:15 AM

Thanks for the clips Henry. That stuff looks real good. Both 3db clips would be totally useable footage. Even the 12db of the street looked good. The 12db of the skyline looked like too much gain. I am not understanding what everyone is complaining about with the low light stuff, I think a few people shot some stuff with auto gain and got freaked out. This footage should hopefully make everyone relax.

Noel Evans · November 7th, 2006, 03:30 AM

Thank you Henry now I dont have to do it... its cold outside tonight :P

BTW Where do you live Henry?

Henry Cho · November 7th, 2006, 04:31 AM

looking at that second set of clips again, i'm wondering now if the noise reduction 1 setting being turned on contributed to the softness, particularly in the moving objects in the image. i'm not saying that focus was tack sharp to begin with, but the moving cars look a little bit softer than the rest of the image to me. if you want to see what nr1 can do on the extreme end, turn in to "high" and start moving the camera around. anything reflecting light will leave a ghostly streak. i'll have to look into that further. in any case, it was left on only for the purposes of this experiment, and i can't imagine why you'd want it on at all at the -3dB gain setting.

pete, i'm using a manfrotto 505 head. i got it when i missed my gitzo g1380 and i kept reading they were the same head. i think it's more of the poor man's g1380... i like the 505, but the drag isn't quite as smooth as i remember on the g1380. in any case, thanks for the kind words.

daniel, hmmm... i'm not sure what the problem is. they're straight mpeg2 files. i'm on the pc and vlc plays them fine. can another mac user verify whether these files are playable or unplayable?

hey noel, i'm in the east village in manhattan. i have the luck of living in the highest building in my immediate vicinity, so i can get an unobstructed 360 view of manhattan and the outer boroughs. handy when you're coughing up a lung and still want something scenic to shoot :).

Poppe Johansson · November 7th, 2006, 05:02 AM

Quote:

Originally Posted by Henry Cho

daniel, hmmm... i'm not sure what the problem is. they're straight mpeg2 files. i'm on the pc and vlc plays them fine. can another mac user verify whether these files are playable or unplayable?

For me files are playing just fine (VLC/Mac).

ps. Thanks for those clips.

Tony Tremble · November 7th, 2006, 05:13 AM

Quote:

Originally Posted by Daniel Boswell

cant get them to play in QT. I changed the suffix to mpeg and all i get is a white screen. VLC wouldnt do it either.

rename the extension to .m2t and they'll play in VLC. I assume you are on a Mac??

Henry,

Nice clips BTW. Thanks for posting them.

The clips at -3dB clearly show the A1 to be a very capable low light performer. One might have better luck brigtening the clips up in post rather than relying on the gain of the camera. As always it'll be a suck and see exercise to determine the best compromise in a given situation.

Regards

TT

Dave Lammey · November 7th, 2006, 06:23 AM

Thanks for posting these clips ... is there any chance you could include comparison clips from another camera, such as an fx1 or z1? I personally have a difficult time gauging lowlight performance unless one can compare directly to another camera under the same conditions ...

November 6th, 2006, 07:05 PM	#1
Henry Cho Major Player Join Date: May 2005 Location: NYC Posts: 516	some low light test footage here is some footage i just shot from my rooftop. camera settings throughout all the clips is: manual mode, 24f, shutter at 1/24, black "stretch", coring "3", noise reduction 1 "low". the first set of clips is a slow tilt up to the manhattan skyline. the first clip was shot -3dB gain with the iris wide open (f3.2) in a pure night sky environment (i.e., it was dark out). the second clip is the same shot at +12dB gain. i actually closed the iris down a bit to f4 to prevent the lights from blowing out too much. i know, not very scientific, but you will get some idea of what's happening. (these files are approximately 120MB each. download to your computer, and remove the "x" at the end of the filename.) http://www.downwiththefuture.com/a1/...e_f3_-3dB.mpgx http://www.downwiththefuture.com/a1/...e_f4_12dB.mpgx the second set of clips is the camera pointed at a traffic intersection about 7 blocks away (gotta love that 20x zoom). not as pretty, but from a comparative standpoint, this is probably a better look at the low light ability of the a1. in both clips, the iris was left wide open, so all you'll be seeing is the change in gain, from -3dB to +12dB). (these files are approximately 35MB each. download to your computer, and remove the "x" at the end of the filename.) http://www.downwiththefuture.com/a1/...ight_-3dB.mpgx http://www.downwiththefuture.com/a1/...ight_12dB.mpgx i really like the a1, and i think it holds up pretty well at the higher gain settings. you could probably take the noise down further by stepping up the coring a bit and adding some further noise reduction via the NR2 setting. i can only leave these clips up for a couple of days.

November 6th, 2006, 07:51 PM	#4
Pete Bauer Wrangler Join Date: May 2003 Location: Eagle River, AK Posts: 4,100	I think that's pretty close. A doubling of light passing the aperture results from an increase in radius of the aperture of the square root of 2, which is 1.414. So: f1.6 x 1.414 = f2.26 f2.26 x 1.414 = f3.2 Of course, mechanical shutters aren't perfectly round and f-stops are rounded-off numbers, but this would be a mathematical approximation of what's really happening in the camera...but close. So call it two stops, or four times the light. EDIT: Just finished downloading and taking a quick look at the clips. Thanks for posting them and their settings, Henry. BTW, most impressive job of smooth tilt on the cityscape clips! You must have both a good tripod and a really steady hand! __________________ Pete Bauer The most beautiful thing we can experience is the mysterious. It is the source of all true art and science. Albert Einstein Trying to solve a DV mystery? You may find the answer behind the SEARCH function ... or be able to join a discussion already in progress!

November 6th, 2006, 08:49 PM	#6
Richard Zlamany Major Player Join Date: Jun 2005 Location: Hamden CT Posts: 470	It looks good, but is the 2nd set of clips out of focus? Last edited by Richard Zlamany; November 6th, 2006 at 09:49 PM.

November 6th, 2006, 07:14 PM	#2
Matthew Nayman Major Player Join Date: Feb 2005 Location: Toronto Posts: 917	Hey Henry, glad to see you're feeling better. Clips are downloading..... BTW, why does everyone say 3.2 is wide open? I know zoomed it is, but wide angle, the lens does 1.6... if my cinema - math is right, that is... 1->2 = 1 stop... 2->2.8 = 1 stop 2.8->4 =1 stop... you can open the camera up nearly another 3 full stops, amore than quadrupling the light... (each 1 fstop doubles available light) So, I would assume with an M2 on the front, zoomed in enough, you have 2.2 on the camera, plus 1 stop from the GG and then 1.4 from a fast lens.... want to try it out! Hurry up vistek.

November 6th, 2006, 07:38 PM	#3
Matthew Nayman Major Player Join Date: Feb 2005 Location: Toronto Posts: 917	Had a look at the clips... Ithink the low light looks amazing man... that shot of the intersection at -3 is unbelieveable... thats at -3db with a 1/24 shutter right? so at 0db witr a 1/48 will look as good...

November 6th, 2006, 08:02 PM	#5
Henry Cho Major Player Join Date: May 2005 Location: NYC Posts: 516	thanks matthew... not 100% but getting there. i think the itch to take the new camera out for a whirl is expediting my recovery :). i apologize in advance for the 120MB files. in retrospect, a similar, or better, test could have been done at a fraction of the filesize.

November 6th, 2006, 09:24 PM	#7
Henry Cho Major Player Join Date: May 2005 Location: NYC Posts: 516	yeah... i was at the long end of the zoom, and had my tripod situated in a wierd spot on the roof, on a bed of stones, so i could see the street. when i shot it, i thought it was set :).

November 7th, 2006, 01:25 AM	#8
Evan C. King Major Player Join Date: Jan 2005 Location: Toronto Posts: 532	Taffic intersection at -3db. Wow. That kinda low light is all I'm looking for. Sorry sony Henry just won this battle for me. I'm gonna get this within a month, now I know it can do everything I want from it.

November 7th, 2006, 03:15 AM	#10
Jack Jenkins Regular Crew Join Date: Jun 2006 Location: Austin, TX Posts: 122	Thanks for the clips Henry. That stuff looks real good. Both 3db clips would be totally useable footage. Even the 12db of the street looked good. The 12db of the skyline looked like too much gain. I am not understanding what everyone is complaining about with the low light stuff, I think a few people shot some stuff with auto gain and got freaked out. This footage should hopefully make everyone relax.

November 7th, 2006, 03:30 AM	#11
Noel Evans Regular Crew Join Date: Feb 2006 Location: Tokyo, Japan Posts: 157	Thank you Henry now I dont have to do it... its cold outside tonight :P BTW Where do you live Henry?

November 7th, 2006, 04:31 AM	#12
Henry Cho Major Player Join Date: May 2005 Location: NYC Posts: 516	looking at that second set of clips again, i'm wondering now if the noise reduction 1 setting being turned on contributed to the softness, particularly in the moving objects in the image. i'm not saying that focus was tack sharp to begin with, but the moving cars look a little bit softer than the rest of the image to me. if you want to see what nr1 can do on the extreme end, turn in to "high" and start moving the camera around. anything reflecting light will leave a ghostly streak. i'll have to look into that further. in any case, it was left on only for the purposes of this experiment, and i can't imagine why you'd want it on at all at the -3dB gain setting. pete, i'm using a manfrotto 505 head. i got it when i missed my gitzo g1380 and i kept reading they were the same head. i think it's more of the poor man's g1380... i like the 505, but the drag isn't quite as smooth as i remember on the g1380. in any case, thanks for the kind words. daniel, hmmm... i'm not sure what the problem is. they're straight mpeg2 files. i'm on the pc and vlc plays them fine. can another mac user verify whether these files are playable or unplayable? hey noel, i'm in the east village in manhattan. i have the luck of living in the highest building in my immediate vicinity, so i can get an unobstructed 360 view of manhattan and the outer boroughs. handy when you're coughing up a lung and still want something scenic to shoot :).

November 7th, 2006, 06:23 AM	#15
Dave Lammey Major Player Join Date: Nov 2002 Location: Simsbury, CT Posts: 247	Thanks for posting these clips ... is there any chance you could include comparison clips from another camera, such as an fx1 or z1? I personally have a difficult time gauging lowlight performance unless one can compare directly to another camera under the same conditions ...