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Sony EX1 Severe LongGop Problems
Hi
I recently tested the Ex1 to the Sony HVR Z7 to the Panasonic HVX201AE and found some very interesting problems regarding the EX1. We shot all kinds of scenes incl. Indoors, Outdoors, Sunset, Dusk all in 25p…and watched all the results on a Baselight System projected in 2k on a big cinema screen. The tests were done for an upcoming cinema documentary.
At first we all loved the EX1 for sharpness, latitude, color rendition and especially for its low-light capabilities. But all this love went away when we looked at shots were the camera moved. On slow pans across f.e. a green grass in the foreground and a city in the background the image suddenly went totally blury. At first we thought the camera was out of focus but as soon as the camera stopped the stellar sharpness was back. On the next telephoto pan across the city skyline all detail was lost as long as the camera moved. It was just a big blur. But it wasn’t motion blurr due to the 25p it was a compression issue. On a shot watching cars drive through the frame the cars looked like ghost images. Totally unsharp but when I started panning with the cars the were totally sharp again. What was the worst though was panning across a field of grass. All detail was gone as long as the camera moved and it was back when the camera stopped. But the killer was when shooting handheld on a second day of tests. The person was walking and as log as he moved with the camera everyting wa fine but as soon as the camera would move out of sync with the person he went blurry.Again it did not look like motion blur. When looking at it in single frames we noticed that only every 8th frame was totally sharp everything else was blurred. We compared all this to identical shots with a Sony HVR Z7 on HDV and the problem was negligible. You could see some motion blurs but nothing that would feel unnatural. The images on the Z7 remained sharp throughout much of the shots even though both cameras use LongGop encoding. When contemplating about this problems my conclusion is that the EX1 due to its higher resolution also has a stronger compression. When the camera starts moving the compression suddenly kicks in and makes it highly visible. Even minor, very slow movements cause this problem. We watched the footage on a 25foot screen which made it highly visible but even on a 42″ Plasma a home it was very noticeable. I am deeply disappointed about this as this LongGop Issue makes the EX1 unusable for big screen projects. The HDV performed much better even though it didn’t have the latitude. But compared on a splitscreen with the EX1 it seems to be the better choice.
Has anybody seen this problem or any thoughts about it? I would have preferred the EX1 because it also offer 60p slowmo and is very good in low light. But I can’t live with these blurr issues unless some solution is found.
Best wishes
Richard Ladkani
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50 Replies
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What were the shutter settings on the respective cams?
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This is a non issue and probably related to setup on the camera, we recently shot at an airshow in the UK with lots of fast pans while following aircraft taking of and landing and this effect did not happen. There has been a lot of debate about it on other forums
See this comparison between a pan on an F350 which does not have this issue and an EX1.
https://www.ingenioustv.com/clips/ex1-motion-test.mov
I’m guessing shutter settings without seeing an example.
Steve Connor
Adrenalin TelevisionHave you tried “Search Posts”? Enlightenment may be there.
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From what I understand, Richard, you are correct. It has to do with the long GOP compression. When shooting at the highest resolution on the EX, the resolution drops during pans. The reason you don’t see it on the Z7 is because the resolution is already lower to begin with. I read this somewhere in this forum. Try doing a search for more info.
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I’m not sure a $6500 camera is the right tool to make big screen projects, unless you can record at a lower compression level. That is where the Convergent Design’s Flash XDR HD-SDI recorder comes in. With the XDR you control the compression level from HDV levels to completely uncompressed with future updates. It will offer 50 Mbps @ 4:2:2, 100 Mbps all i-frame 4:2:2 and up to 160 Mbps all i-frame 4:2:2 to begin with.
https://www.convergent-design.com/I believe this will be the perfect solution to your projects and maximize the EX1 CMOS system.
Good Luck
Michael Palmer -
Hi there
The shutter was set to 1/50 of a second. It was identical on all other cameras.
By the way I was looking for a little brother for my main camera. I also tested a F900R an HDX900 and S16mm with the new Kodak Vision 3. The only camera with the LongGop Issue I described was the EX1. All other cameras performed well on pans and movement. The F900R won as the best camera for the main shoot. The little brother should have been the EX1 but with this LongGop blurry issues it will most likely have to be the Sony HVR-Z7. The HVX201 is also good but it only records 16min HD on a 16gb card which is too little. We have 80 shooting days.Regarding the shoot with planes starting and landing… I cam not surprised you didn’t have a problem as you moved the camera with the planes. If something moves with the camera it remains sharp. But if you pan across a landscape with alot of detail or something doesn’t move with the camera but against it it becomes very visible.
Any more comments are welcome.
Thanx
Richard -
Hi Michael
Looked at this Compact Falsh Recorder. It looks interesting but I am not sure if it will solve the problem.
The question is when the LongGop Problem is generated? If it happens before the image is output over SDI then it’s not a solution. If it indeed only happens when it’s written to the SxS Card (which I doubt) then there is still two issues that are unpractical.1. You are generating huge amounts of Data: 2,4 hours need 192gb of storage. An EX1 needs approx. 1/4 of that.
2. You need to feed Audio directly into the flash card which can become a cable nightmare when wanting to shoot “run’n gun” stuff.
3. It costs an additional 5000$
It might become interesting down the road but in the end it doesn’t really help me with the issues described.
Best
Richard -
The HD-SDI signal from the EX1 is before any compression. I’m sure the 50 Mbps setting would yield a superior image to the EX1 HQ record mode.
As to the run & gun, Convergent Design is working on a smaller second unit that will have only 2 cards that you can wear on your belt, it will also have HD-SDI & HDMI compatibilities for recording.
The price is a bargain for what you’re getting, low cost compact flash cards and lower compression result in higher quality video. You can purchase 32 gig cards for $150 that will record 100 Mbps all i-frame 4:2:2. So now your into extremely high quality HD recording for an affordable price. No one is going to sell a full raster HD camera for under 14K that can produce what you can get from the EX1 XDR combo.
Good Luck
Michael Palmer -
Sounds interesting but let’s get the focus back to the EX1.
I am looking for solutions to the problem without having to buy extra equipment. The EX1 is the most hyped camera these days. I would like to find out why nobody has talked about the LongGop Problem yet. It is so obvious others must see it too. If not then I would like to know why and how do they get around it…
Best
Richard Ladkani -
To Steve Connor
I just watched your clip of a car moving by. It has the same problems. The car remains sharp whereas the grass and the trees loose all detail as soon as you start moving. This is not simple motion blur. It is compression kicking in. Now imagine this on a big screen without the car moving but just the pan if you want to establish the scenery. It would be completely blurred…even if you would pan much slower than that. Just try again and post the result please. If you would compare that same pan with a the HDV Z7 it would be much better in terms of detail.
Best
Richard -
How are you viewing your footage Richard because I don’t see the problem you are talking about in the posted clips.
Steve Connor
Adrenalin TelevisionHave you tried “Search Posts”? Enlightenment may be there.
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