EX1 Fails Strobe Test at DVinfo.net

Mike Wade · January 3rd, 2008, 02:39 AM

Just how significant is the strobe test failure as outlined in the following:

http://techthoughts.org/2008/01/02/s...s-strobe-test/

as a potential buyer should this put me off ?

Eric Pascarelli · January 3rd, 2008, 03:07 AM

Whereas I am sure that the EX1 will fail many a "strobe test" I think that the test cited in the article was not very thorough. I plan to do one of my own.

That said, if you need a camera that will exhibit none of the "rolling shutter" artifacts at any time, you might want to consider something else.

But on the balance, there is nothing out there that comes close to the EX1 in terms of performance/size/price.

The HVX200 has no such artifacts but pales significantly in every other way in my opinion (except that it's a bit cheaper!).

Vaughan Wood · January 3rd, 2008, 03:40 AM

I have just finished editing my first wedding last weekend with the EX, and I love the footage.

I stopped using my FX 7 for weddings as I couldn't get over the hurdle of the photgrapher's flashes, especially during the bride's preparations, when I use a lot of slow motion.

I found the EX codec to be MUCH better in handling the video distortion with flash guns, with only one or two frames affected, whereas the FX 7 would wreck up to 7 frames when slowed down 50%.

I can live with that, and the beautiful images I got throughout the day and night at a very dark reception just blew me away.

The EX does show noise in dim conditions, but just hit it with some light (sony camera light even with the dimmer almost fully on) and the image was like the old PD 150 days, only better.

Cheers Vaughan

Sulev Sepp · January 3rd, 2008, 08:42 AM

Hi Vaughan,

Happy New Year!!!

Did you filmed wedding in 1920x1080 HQ/35Mb mode?
How You managed emptying of cards on location?
How dark was it actually? Did You used on-camera light or You filmed all event without???

With
Best
Sulev

Steven Thomas · January 3rd, 2008, 09:32 AM

I'm a bit confused on the image resolution, 1024x576?
Was it possible for you to attach the native frame resolution. These are of course resized. I realize that they might of been resized for the internet, but since they were close to 1.7 MB per image, this must not be the case.

Kit Hannah · January 3rd, 2008, 10:35 AM

Quote:

Originally Posted by Steven Thomas

I'm a bit confused on the image resolution, 1024x576?
Was it possible for you to attach the native frame resolution. These are of course resized. I realize that they might of been resized for the internet, but since they were close to 1.7 MB per image, this must not be the case.

Agreed 100%. Vaughan, you're not doing the camera justice by resizing the picture, outputting it at a lower quality, etc. Not to be harsh, but if I was looking to purchase this camera and I thought THAT was what it's going to look like, I wouldn't buy it. The images do not look good, although clear, they appear to have a lot of aliasing.

Could you repost some raw grabs?

Thanks

Andy Schocken · January 3rd, 2008, 01:03 PM

let's keep this thread focused on the issues brought up by the initial post. the strobe performance is an important question to answer with this camera, and i'm curious to hear relevant user reports. anyone else have any input?

Ray Bell · January 3rd, 2008, 01:35 PM

maybe I'm misunderstanding the issue with flash affecting the EX1 footage....

Isn't it very very easy to fix in post??? you just insert a white frame over the flash area... or blow it out with exposure compenstation...
and add in a audio flash sound...

anything wrong with that?

Andy Schocken · January 3rd, 2008, 01:45 PM

there are workarounds you can use in some situations, but that doesn't make it a non-issue, especially if it's a rapidly recurring flash. notice in the police car footage that the flash illuminates rain drops on the lens- you're not going to be able to correct for that on the dark side of the frame.

Vince Gaffney · January 3rd, 2008, 02:01 PM

That looks like it was shot through a window or windshield. If it was, I can't think of a worse way to demonstrate anything this or any other camera is doing. Or how it can be cleaned up in post.

Steven Thomas · January 3rd, 2008, 02:02 PM

Well,
you have to decide if it's a deal beaker, because it's there. That's all there is to it.
All of these cameras have shortcomings, and this artifact is one for a "current" CMOS based camera.

If it's occasional flashes, yes you can fix in post, but if it's continuous, you could probably fix it, but it will chew up some time.

I was happy to see the EX1 under the strobe effect with my moving head lights do not have obvious partial exposures. In fact it looks great.
Why? I'm not sure, probably due to the mechanical shutter on these type of fixtures.

Sebastien Thomas · January 4th, 2008, 04:58 AM

I had a look to some footages I took in Notre Dame de Paris, France. While flashes are not allowed inside, people seems to have nothing to care about. I have many shoot with flash.
Looking closer to my footage, I noticed that two of them made a "partial exposure".

Seems I can't upload the files. Here are the URLs :

http://www.lecentre.net/video/stills...-exposure1.png
http://www.lecentre.net/video/stills...-exposure2.png

While you clearly see this, it only involves 2 consecutive frames and you won't notice it in a normal playback.

FYI, the shot was 1080@25p, shutter off (1/25) wide open (no gain I think).

Kit Hannah · January 4th, 2008, 01:35 PM

So is this a CMOS problem or could it be from the GOP? If the GOP is basically using information from other frames in the GOP, it seems like the camera could just be confused...

Alister Chapman · January 4th, 2008, 01:45 PM

It's a CMOS problem. Just about every CMOS video camera suffers from it to a greater or lesser degree.

Patrick McLoad · December 27th, 2010, 05:29 PM

Alister:

Have you or anyone else used a Sony PMW-350 for aerials from a chopper? I don't want to go up in a chopper on a client's dime with a camera that will be problematic with the rolling shutter effect....I'll rent a 2/3" CCD camera if I have to....but is this necessary?

Thanks.

Patrick McLoad

January 3rd, 2008, 02:39 AM	#1
Mike Wade Regular Crew Join Date: Feb 2005 Location: Holmfirth, West Yorkshire, UK Posts: 161	EX1 Fails Strobe Test Just how significant is the strobe test failure as outlined in the following: http://techthoughts.org/2008/01/02/s...s-strobe-test/ as a potential buyer should this put me off ?

January 3rd, 2008, 03:40 AM	#3
Vaughan Wood Major Player Join Date: Dec 2006 Location: Melbourne Australia Posts: 278	I have just finished editing my first wedding last weekend with the EX, and I love the footage. I stopped using my FX 7 for weddings as I couldn't get over the hurdle of the photgrapher's flashes, especially during the bride's preparations, when I use a lot of slow motion. I found the EX codec to be MUCH better in handling the video distortion with flash guns, with only one or two frames affected, whereas the FX 7 would wreck up to 7 frames when slowed down 50%. I can live with that, and the beautiful images I got throughout the day and night at a very dark reception just blew me away. The EX does show noise in dim conditions, but just hit it with some light (sony camera light even with the dimmer almost fully on) and the image was like the old PD 150 days, only better. Cheers Vaughan Attached Thumbnails

January 3rd, 2008, 08:42 AM	#4
Sulev Sepp New Boot Join Date: Apr 2006 Location: Tallinn, Estonia Posts: 20	Please details Hi Vaughan, Happy New Year!!! Did you filmed wedding in 1920x1080 HQ/35Mb mode? How You managed emptying of cards on location? How dark was it actually? Did You used on-camera light or You filmed all event without??? With Best Sulev

January 3rd, 2008, 01:03 PM	#7
Andy Schocken Regular Crew Join Date: Jul 2006 Location: Brooklyn, NY Posts: 54	strobe test let's keep this thread focused on the issues brought up by the initial post. the strobe performance is an important question to answer with this camera, and i'm curious to hear relevant user reports. anyone else have any input?

January 3rd, 2008, 02:02 PM	#11
Steven Thomas Trustee Join Date: Sep 2005 Location: Gilbert, AZ Posts: 1,896	Well, you have to decide if it's a deal beaker, because it's there. That's all there is to it. All of these cameras have shortcomings, and this artifact is one for a "current" CMOS based camera. If it's occasional flashes, yes you can fix in post, but if it's continuous, you could probably fix it, but it will chew up some time. I was happy to see the EX1 under the strobe effect with my moving head lights do not have obvious partial exposures. In fact it looks great. Why? I'm not sure, probably due to the mechanical shutter on these type of fixtures. Last edited by Steven Thomas; January 4th, 2008 at 10:02 AM.

January 3rd, 2008, 03:07 AM	#2
Eric Pascarelli Major Player Join Date: Nov 2007 Location: Los Angeles, CA Posts: 498	Whereas I am sure that the EX1 will fail many a "strobe test" I think that the test cited in the article was not very thorough. I plan to do one of my own. That said, if you need a camera that will exhibit none of the "rolling shutter" artifacts at any time, you might want to consider something else. But on the balance, there is nothing out there that comes close to the EX1 in terms of performance/size/price. The HVX200 has no such artifacts but pales significantly in every other way in my opinion (except that it's a bit cheaper!).

January 3rd, 2008, 09:32 AM	#5
Steven Thomas Trustee Join Date: Sep 2005 Location: Gilbert, AZ Posts: 1,896	I'm a bit confused on the image resolution, 1024x576? Was it possible for you to attach the native frame resolution. These are of course resized. I realize that they might of been resized for the internet, but since they were close to 1.7 MB per image, this must not be the case.

January 3rd, 2008, 01:35 PM	#8
Ray Bell Regular Crew Join Date: Nov 2004 Posts: 1,414	maybe I'm misunderstanding the issue with flash affecting the EX1 footage.... Isn't it very very easy to fix in post??? you just insert a white frame over the flash area... or blow it out with exposure compenstation... and add in a audio flash sound... anything wrong with that?

January 3rd, 2008, 01:45 PM	#9
Andy Schocken Regular Crew Join Date: Jul 2006 Location: Brooklyn, NY Posts: 54	there are workarounds you can use in some situations, but that doesn't make it a non-issue, especially if it's a rapidly recurring flash. notice in the police car footage that the flash illuminates rain drops on the lens- you're not going to be able to correct for that on the dark side of the frame.

January 3rd, 2008, 02:01 PM	#10
Vince Gaffney Regular Crew Join Date: Dec 2005 Location: Chicago, IL Posts: 146	That looks like it was shot through a window or windshield. If it was, I can't think of a worse way to demonstrate anything this or any other camera is doing. Or how it can be cleaned up in post.

January 4th, 2008, 04:58 AM	#12
Sebastien Thomas Major Player Join Date: Nov 2007 Location: Paris, France Posts: 210	I had a look to some footages I took in Notre Dame de Paris, France. While flashes are not allowed inside, people seems to have nothing to care about. I have many shoot with flash. Looking closer to my footage, I noticed that two of them made a "partial exposure". Seems I can't upload the files. Here are the URLs : http://www.lecentre.net/video/stills...-exposure1.png http://www.lecentre.net/video/stills...-exposure2.png While you clearly see this, it only involves 2 consecutive frames and you won't notice it in a normal playback. FYI, the shot was 1080@25p, shutter off (1/25) wide open (no gain I think).

January 4th, 2008, 01:35 PM	#13
Kit Hannah Major Player Join Date: Jan 2007 Location: Fresno, California Posts: 528	So is this a CMOS problem or could it be from the GOP? If the GOP is basically using information from other frames in the GOP, it seems like the camera could just be confused...

January 4th, 2008, 01:45 PM	#14
Alister Chapman Inner Circle Join Date: Dec 2005 Location: Bracknell, Berkshire, UK Posts: 4,957	It's a CMOS problem. Just about every CMOS video camera suffers from it to a greater or lesser degree. __________________ Alister Chapman, Film-Maker/Stormchaser http://www.xdcam-user.com/alisters-blog/ My XDCAM site and blog. http://www.hurricane-rig.com

December 27th, 2010, 05:29 PM	#15
Patrick McLoad Regular Crew Join Date: Mar 2003 Location: Houston, Texas Posts: 52	Helicopter Shooting Alister: Have you or anyone else used a Sony PMW-350 for aerials from a chopper? I don't want to go up in a chopper on a client's dime with a camera that will be problematic with the rolling shutter effect....I'll rent a 2/3" CCD camera if I have to....but is this necessary? Thanks. Patrick McLoad