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Image sharpness and grainy blacks/blues

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Drew Keo
Image sharpness and grainy blacks/blues
on Apr 3, 2012 at 2:56:56 pm

Hello,

I am ashamed to say I've used a NX5U for two years and I still have trouble with these two issues (please see clip below):
Image Sharpness: I always feel as though my video does not look sharp. I use manual focus and shoot in HD. What other settings might help me achieve the sharpest image? Online, I've seen a common complaint about this camera is that it can't achieve sharp images, but then someone always posts a comment underneath saying that it is all in the settings.
Grain: I notice a lot of grain in my blacks (or whenever someone has a dark jacket on). Any tips of reducing grain, when everything else looks good (other than asking subjects not to wear black).

Please see the clip below that I recently shot. Should I be achieving a sharper image? And notice the grain in the female's blue top as well as the black desk pad.







Tips/knowledge much appreciated.

Best,
keo


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Glyn Gray
Re: Image sharpness and grainy blacks/blues
on Apr 3, 2012 at 3:44:32 pm

Are you using any Picture Profiles?

I would suggest moving the gain down to -3 or even -6 see if this removes the noise for you. You could also bump down the blacks int he picture profile as well.

Inside the Picture Profile there is a section called detail. Bump the sharpness up some and test.

See if any of this helps?

Glyn Gray - Editor/Videographer


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David Eaks
Re: Image sharpness and grainy blacks/blues
on Apr 3, 2012 at 11:11:44 pm

If you haven't noticed, the NX5 does not hold focus when you zoom. So if you zoom in to get critical focus, then zoom out, you will completely lose that focus. The expanded focus and peaking features can help you work around this. Honestly, I think there was only one shot that looked to be in good focus, two seconds at 2:47-2:49 (I'm viewing on an iPhone 4s).

Taking the focus issue, along with the tips from Glyn, -3db gain, use a picture profile to drop master blacks and bump up the detail, you should definitely be able to get images that you are happy with.

I just bought my third NX5 and am very happy with the camera in general, just be aware that the small sensors on the NX5 are limiting. Don't expect to get the image quality of a PDW 800 or something, there is good reason for the large price gap in cameras, you are seeing one of those reasons in the blacks. Good thing is, I doubt that the majority of clients would notice such a thing. Even if it is glaring and nauseating to "us".


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Rick Diamond
Re: Image sharpness and grainy blacks/blues
on Apr 4, 2012 at 4:47:41 pm

The camera most definately should hold focus after zooming out. If it isn't you'll need to adjust the back focus.

As far as sharpness goes, it depends on your expectations. I shoot and edit footage from the EX3 and NX5 regularly. Without question, the images from the EX3 are considerably sharper. You'll be able to achieve a decent amount of perceived resolution if you throw a lot of light on the subject. Exteriors on a bright sunny day are a perfect example. The EX3 and NX5 match fairly well under these conditions. Unfortunately, the image quickly deteriorates when shooting interiors using available light.

As with any camera.I would be careful when turning up the detail. If you go too high, the image will "ring" and look unnatural. In my side by side tests, I find shooting progressive will give you a very slightly sharper image than interlaced. And, as mentioned, whenever the light allows, shoot at -3dB or -6.

Rick


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David Eaks
Re: Image sharpness and grainy blacks/blues
on Apr 4, 2012 at 8:21:27 pm

[Rick Diamond] "The camera most definitely should hold focus after zooming out. If it isn't you'll need to adjust the back focus."

Well that is great news! So, exactly where is the back focus adjustment on the Sony HXR-NX5U?


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Rick Diamond
Re: Image sharpness and grainy blacks/blues
on Apr 4, 2012 at 10:57:42 pm

You may need to contact Sony to have them adjust the back focus. I couldn't find it, so I googled it and discovered that back focus is an issue for many NX5Us. Sony most likely will be able to tell you how to adjust it yourself. It's also known as flange focus.

Rick


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David Eaks
Re: Image sharpness and grainy blacks/blues
on Apr 4, 2012 at 11:23:58 pm

Great! I'll contact Sony and see what they say.


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Ken Mitchell
Re: Image sharpness and grainy blacks/blues
on Apr 5, 2012 at 1:01:03 am

I had read that the backfocus issue is a problem with some NX5U cameras. I was considering a purchase.. would be very interested in Sony's reply.


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Drew Keo
Re: Image sharpness and grainy blacks/blues
on Apr 6, 2012 at 1:26:24 pm

Thanks everyone for your responses. I tried some of your suggestions with a personal project. The fact that much of the above video was out of focus was sobering. I don't know if I can blame the camera, but perhaps I should reach out to Sony.


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Drew Keo
Re: Image sharpness and grainy blacks/blues
on Apr 6, 2012 at 5:33:34 pm

Hi All,

Please see clip below. I am still getting grain (on red wall and blue shirt). Here are my gain settings and picture profile. Please let me know if something jumps out at you that might be responsible for my grainy image.







I was shooting 1080/24p. Iris as wide as possible. Full lowel kit (so there was a lot of light).

Gain: -6, -6, -6

Black Level: Master -4, RGB all 0
Gamma: Cinematone
Black Gamma: Range Middle, Level +2
Knee: Auto
Color Mode: Type Cinematone, Level 8
Color Level: Phase 0, Depth 0
Detail: Level +5


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john lenihan
Re: Image sharpness and grainy blacks/blues
on Apr 6, 2012 at 6:18:03 pm

The red wall does not have graininess.

Graininess is smaller speckles.

This is demonstrating pixelation, usually from too low of a bit rate during compression.

John

John Lenihan

LeniCam Video Productions
http://www.lenicamvideoproductions.com


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Drew Keo
Re: Image sharpness and grainy blacks/blues
on Apr 6, 2012 at 6:32:20 pm

Pixelation in compression? Does that mean it is something happening in post or is my raw footage damaged?


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john lenihan
Re: Image sharpness and grainy blacks/blues
on Apr 6, 2012 at 6:37:37 pm

Well, I was referring to post, however, it could have been in the camera also.

I am assuming you were shooting at the highest quality the camera allows. That would be 1920 by 1080 by 60i, or 30p. Within that, on the camera, under the recording format, there are three levels of quality, FX, FH, FG or something like that. FX is the highest and produces the highest number of bits and best image. The other ones less.

What setting is your camera on.

John Lenihan

LeniCam Video Productions
http://www.lenicamvideoproductions.com


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Drew Keo
Re: Image sharpness and grainy blacks/blues
on Apr 6, 2012 at 6:42:34 pm

I was shooting 1080/24p FX (Iris as wide as possible)

Gain: -6, -6, -6

Picture Profile:

Black Level: Master -4, RGB all 0
Gamma: Cinematone
Black Gamma: Range Middle, Level +2
Knee: Auto
Color Mode: Type Cinematone, Level 8
Color Level: Phase 0, Depth 0
Detail: Level +5


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