Ex Picture Profile Thread

My own experience with the field of view being constant across resolutions suggests that what I've read about the EX series using the whole imager and then resampling the result is indeed the case. Why that results in higher video levels, I'm not sure, but it's possible that Sony calculated the amount of noise reduction happening through downsampling and added an appropriate compensating gain (but that's my speculation, purely).
Any other methods, such as gain and gamma stretches, will, of course, lift noise levels.
 
Is it good form to turn the shutter off in low light situations? I'm not quite clear what happens when you turn the shutter off in any situation. I've always just left it on, and have yet to change anything.
 
Turning off the shutter is, in film parlance, roughly equivalent to a 360° shutter angle, if that were possible. This allows light to accumulate on the CMOS chips for the FULL duration of each frame. The effect, besides a brighter image, is that the exposure duration is double that of a 180° shutter, so fast moving objects will have blur streaks twice as long as with the shutter set to it's slowest speed/angle. The difference, at 24fps, would be the difference in position of an object in motion in 1/48th of a second, versus 1/24th of a second for shutter off. I hope that wasn't too confusing. :)
 
So shutter off is good to grab some extra light, but at the expense of clarity with motion streaking. So it could help in a club with a band playing, staying relatively put. With 'shutter on' you control the shutter rather than just having it be relative to the frame rate.
 
Yes, that's correct. Not a problem with relatively low motion stuff, and may even be a useful effect in some styles of shooting. But definately adds a stop or so of extra light.
 
Mark

I'm going out to do some beauty shots of a rental cottage on the rocky coast od Trinidad.

http://www.dragonflycottage.net/photos.html

If I'm panning and getting shots with much detail, do you think 720 would handle the motion better than 1080? I am thinking that since at 720 you aren't spreading the image out to make it 1080, the 35mbps vbr may have more resolution to deal with pans without softening the image as much. I'm replacing the video that is on the link. Let me know what you think soon, as I'm on my way out.
 
I have mixed impressions of 720P as implimented in the EX series. I felt that the color subsampling suffered disproportionately to the luma sampling. Theoretically, 720 is using half the bandwidth in pixels, so the CODEC should have better quantizing of motion data, but in practice, I can't say it fully offsets the loss of resolution. I always shoot 1080P/24, as I feel THAT looks the cleanest.
 
Oh well - too late. I shot it all in 720. Importing now. It's mostly for web so it's not terribly important.
 
Don't worry about it if it's destined for the web. The color subsampling of web video CODECs is far worse than anything in the camera. :)
 
How much light did you have available?

I think there will always be visible noise when shooting 0dB and above gain levels. I shoot at -3dB, which pretty much pushes it to invisibility. But of course if you're boosting black gamma, things are going to get noisy.
 
That's the thing. I shoot at -3db too. And it was outside in the sun. The worst was shooting a flower with a fully out of focus Bokeh of a gravel drive. Very noisy. Another I saw was in a deep blew sky while shooting a flag. I had a polarizer on to saturate the colors. Many shots look pretty good. I'll examine closer tomorrow. Maybe make a screen shot.
 
I've noticed that there is SOME noise visible in grey, cloudy skies, usually if I underexpose a little, and the camera is hot from being in the sun. Just the other day, I noticed that my EX3 had no visible noise in the display with focus assist magnification at +12dB gain, looking at some dark velvet drapes in a dimly lit room. But 1/2-hour later, the same scene, with focus assist to magnify, noise was clearly visible. Temperature has a lot to do with it. When I was shooting an air show, the camera was in the direct, hot sun for 7-1/2 hours. But when I watched the footage on my 30-bit color projector, the noise was less prevalent, and I could see more detail, than when it was displayed on my Vizio 47" LCD. A lot depends on the bit depth and gamma curves of the display. Some exaggerate noise alot.
 
basspig said:
I've noticed that there is SOME noise visible in grey, cloudy skies, usually if I underexpose a little, and the camera is hot from being in the sun. Just the other day, I noticed that my EX3 had no visible noise in the display with focus assist magnification at +12dB gain, looking at some dark velvet drapes in a dimly lit room. But 1/2-hour later, the same scene, with focus assist to magnify, noise was clearly visible. Temperature has a lot to do with it. When I was shooting an air show, the camera was in the direct, hot sun for 7-1/2 hours. But when I watched the footage on my 30-bit color projector, the noise was less prevalent, and I could see more detail, than when it was displayed on my Vizio 47" LCD. A lot depends on the bit depth and gamma curves of the display. Some exaggerate noise alot.
Click to expand...


You have to be careful with TVs, as opposed to real compu monitors (or cheap TVs with poor noise reduction, like a Vizio). If you have a good projector, it will apply very good real-time noise reduction. I personally was shocked when I first saw a familiar blu-ray running straight to a compu monitor. On my front-projector, I never saw a problem, but on a compu screen the noise was insane.

That said, noise is an overstated issue, I think, in these forums. Many major Hollywood pics have lots of noise in certain scenes. Until I started thinking about noise, I rarely gave it much thought.

On the other hand, teh harder the noise reducer has to work, the less sharp the final image.
 
Yeah it was just surprising to see the noise I did in broad daylight. I think like on my Sony H7 point & shoot, the camera's noise reduction has trouble resolving areas of the highest detail, and/or out of focus areas. My most noisy area was the bokeh area when I was focused on a flower, with both ND filter 2 and polarizer on the lens. Something about that combo made noise for me. Though I was surprised to see noise on the blue sky area of a shot of a flag waiving.

Maybe it's not a big issue in context. It just seems to stick out when played next to the other clips that day. These are crops at 100% image size:

picture.php


picture.php
 
BBC made these settings for the EX1
http://downloads.bbc.co.uk/rd/pubs/whp/whp-pdf-files/WHP034_ADD30-rev1-Sony-PMW-EX1-and-EX3.pdf
what do you think about?

CAMERA SET menu:
AGC Limit: 12
AGC Point: F/2.8
A.Sht Point F/5.6

PICTURE PROFILES menus, manual settings:
Matrix: On
Select: Standard {v}
Detail: On
Level: 0 {v}
Frequency: 30
Crispening: -45
H/V ratio: 0
White Limiter: 0
Black Limiter: 0
V DTL Creation: Y
Knee APT Level: 0
Skin Tone Detail: Off
Knee: On
Auto Knee: Off
Point: 87
Slope 60
Gamma-Select: Std3 {v}
Black 0
Low Key 0
 
With those black and white limiter settings, there will be black halos around highlight spots/edges. Better to turn those up to 80 or better, or shut off Det Enh entirely.

Robert, yes, noise is prevalent on most of my commercial Blu-ray movie collection. I watch a lot of them on my projection system. The Vizio claims to be 24-bit color, but it acts more like 18-bit color, because it doesn't display gradiants without distinct bands. My projector shows smooth gradients, OTOH. Lack of bit dept exaggerates the noise pixels because it often increases the contrast between the noise pixels and the rest of the image. That's why I found the noise to be not so noticable on my 30-bit projector. And on that playing field, the XDCam footage runs circles around a lot of Hollywood's stuff.
 
You must log in or register to reply here.
Back
Top