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  • Hey all, just changed over the backend after 15 years I figured time to give it a bit of an update, its probably gonna be a bit weird for most of you and i am sure there is a few bugs to work out but it should kinda work the same as before... hopefully :)

Grain issues, motion blur issues.

N

NIck Cangello

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HI guys, shooting my kids skateboarding on a Raven.

I am shooting wide open with varibale ND almost closed all the way on sunny days.. I get home and the footage is so very grainy.. I am not getting good quality out of this camera. I need help.

I am shooting 4khd, 12:1, 60base 60 fps, shutter around 500 and still I want the slow mo to be cleaner..

Any help will be much appreciated.

Thank you!
 
1. Have you recently done a blackshade calibration of your sensor?

2. What ISO are you targeting?

3. 12:1 compression is relatively high for 4K. I tend to shoot around 8:1 for 8K, 5:1 for 6K, and even less for lower resolutions.

4. When you say shutter around 500, I assume you mean 1/500? Your title says motion blur issues but this should be rather motion-blur free. Typically people shoot 1/120 for 60fps material, so over 4 times faster shutter should be plenty crisp.

5. What is your lens? Wide open performance is typically softer than stopping down. That could be an added layer of mushy feeling to your image, exacerbated by the relatively high compression.
 
Aaron, do you think the fact that I am using a super cheap variable nd is making this worse too?
 
Thanks for responding.. iso 800 - i will most def lower the compression next time.

Yes to 1/500, looking at the footage again, It is actually motion blur free..

Lens is the sigma art 16-35, and you are so right the image is for SURE mushy.. I hate it!

Also no to the calibration, I am not sure what that is and should I be doing it?
 
Sensor calibration: http://docs.red.com/955-0154/REDRAV...ent/SensorCalibration/1_Intro_SensorCalib.htm

I would recommend shooting at the camera's 4.5FF mode so you are utilizing the full sensor. When scaling down to standard UHD (3840x2160) it will make any grain smaller and image quality a bit better and also gives you the ability to adjust crop slightly in post. If you are using an ND, you should probably target a much lower ISO to achieve a proper exposure balance to make sure you are allowing enough light into the sensor and exposing properly using the exposure tools on the camera.

There is a good guide for that here: https://www.red.com/red-tech/low-light-capture

While it mentions low light, it is a good guide for using the exposure tools built into the camera. Another good guide: https://www.red.com/red-tech/red-tech-iso-settings

Also you mentioned you are shooting at project base of 60fps and 60fps. Are you planning on playing back at 60fps or are you shooting for slow-mo? If shooting for slow-mo you really should set your project to 24 or 23.98. If you want to maintain audio capture while shooting varispeed, you can do that as well: http://docs.red.com/955-0154/REDRAV...Audio/Varispeed_Audio.htm?Highlight=varispeed
 
A cheap variable ND can definitely add some softness as well.

Do you have a r3d frame you could share with us to evaluate?

If you don't know how, download Redcine-X Pro, open your video file, navigate frame by frame to the sharpest frame you can find, and then click a button that looks like this:
R3D_Snapshot_17x15.png


The r3d frame will be stored wherever you have it set in Edit > Preferences > Snapshot

Host that on dropbox or google drive and link us here and we'll be able to check it out.

andrewhake said:
I would recommend shooting at the camera's 4.5FF mode so you are utilizing the full sensor. When scaling down to standard UHD (3840x2160) it will make any grain smaller and image quality a bit better and also gives you the ability to adjust crop slightly in post. If you are using an ND, you should probably target a much lower ISO to achieve a proper exposure balance to make sure you are allowing enough light into the sensor and exposing properly using the exposure tools on the camera.
Click to expand...

A bit of a moot point if OP wants a 16:9 project in the end. Remember the Raven sensor has a fairly wide aspect ratio, so you'd have to crop left and right and end up with a 3840x2160 file in the end anyway. I'd only shoot 4.5K FF if I was delivering wider than 2.13:1 (the sensor's aspect ratio) or I really wanted that left/right room to reframe for 16:9, but that isn't something I'd do personally.
 
Upload a r3d snapshot and Im pretty sure you will get lots of very accurate comments on what could have been done to improve the image.
 
Do a test with and without the "super cheap variable" ND. You will see a huge difference. Be sure to calibrate your sensor at the frame rate you will be using and apply that calibration.
 
Nick,

I turned the "detail" down to "0" before converting your image over to "IPP2'. Also, the first image below was shot at F2.2 and the second was shot at F4 according to your metadata. Maybe "stop down" your lens more and do everything Aaron suggested in Post#2 above.


Adam_1.0000302_F.0000000.jpg



Adam2.0000000_F.0000000.jpg
 
Last edited:
lWbMuG7.jpg


This is not grainy and blurry, just not the sharpest and not the artifacts free (compression!) image ever.
You're good. :smile5:
 
Sabovic,

I thought so too, but I thought maybe I was missing something, glad to have another observation.
 
The focus is actually a little off on these. In the first one, it's a little bit ahead of the skateboarder. Hard to nail and anticipate his position, so I don't blame you. He probably comes into focus just shortly after this frame, too.

29958752637_e9d9c131c3_k.jpg

Full res: https://farm2.staticflickr.com/1922/29958752637_eaf537f30f_o.png

This one is a bit past the two kids in the front. The kid in the back and the trees looks sharper to me.

44895681801_490b494323_k.jpg

Full res: https://farm2.staticflickr.com/1914/44895681801_62f8144938_o.png

Outside of color work, for these I did a slight chroma noise cleanup, added some subtle sharpness, and added grain.
 
Couple of things.

1) A cheap ND could def affect sharpness.
2) If you are shooting slow-mo, definitely lower your compression - that will help minimize artifacting
3) Consider lowering your ISO to maybe 320 or 400. That will clean up your shadows.
4) Try a straight 180 degree shutter. It may not be as sharp, but could look more natural.

All the best
 
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