Any ideas on the differences in image quality between 120fps and 60fps

Site Notices

[ARCHIVED THREAD] - Any ideas on the differences in image quality between 120fps and 60fps

Posted: 12/9/2018 9:40:49 PM EDT

I just got a Sony AX53 for recording sports game films.
I really like the camcorder so far, I took it to the field to film a practice, from the press box, with different settings to get the feel for the camcorder.
The biggest difference that I noticed was that at 120 frames per second, under the stadium lighting, the video was grainy(lossy?), while at 60 frames the image was much sharper, and colors more vibrant.
They are both supposed to be filming at 1080p for both frame rates.
Both modes were filmed in MP4 XAVC S HD format (I think), it doesn't actually give the option in 120 to select the format.
120 frames was recording at 60Mbps, I do have the option to set it to 100Mbps.
60 frames was recording at 50Mbps.

That was the only setting changed. Under normal daylight, it is much more difficult to see a loss of quality at 120, but even in my home lighting I get the grainy images at 120 frames.
I probably don't need 120, but it does noticeably lessen the blur when panning.

Does anyone have any idea why the quality is different between the two?

Camera in exact same position and zoom, had to just take crops because persec/opsec etc..
120 FPS

Attached File

60 FPS

Attached File

Posted: 12/9/2018 10:23:40 PM EDT

[#1]

Not enough light.

Posted: 12/9/2018 10:33:24 PM EDT

[#2]

Double frame rate likely means double shutter speed, so unless you added double light, the difference was made up with increasing iso, so there's your extra noise.

Posted: 12/10/2018 12:08:01 AM EDT

[#3]

Quote History

Quoted:
Double frame rate likely means double shutter speed, so unless you added double light, the difference was made up with increasing iso, so there's your extra noise.

View Quote

Just checked what you said, it is indeed the case. 60 FPS was running on a 1/60 shutter speed (set by auto), 120 FPS was 1/125(set by auto).
Doubling the light isn't possible, and I'm guessing no amount of changes to the settings will improve things if lighting is the issue on 120p.

Maybe I could just increase the shutter speed some at the loss of some brightness to decrease the blur on 60p, I'm not getting the same noise penalty at 1/125 shutter speed on 60p as I am on 120p, but the brightness is about the same. I also have a 1/90 and 1/100 speed options between 1/60 and 1/125 on 60p.

The noise at 120p isn't terrible, but it does make the image less clear than the last generation Sony camcorder I was using last year, albeit a lesser frame rate. The blur on 60p at 1/60(auto) isn't really that bad either, I'm just trying to find the optimal settings.
Losing slow motion isn't really too big of a deal, I was only going to slow down shots on goal as a replay after the shot, or questionable calls by the ref.

I suspect, unless the game is in full daylight I will just keep it at 60p auto shutter, but I might as well test some of the settings just in case.

Thanks for the help! I was scratching my head about this one, not a big photography guy.

Posted: 12/10/2018 12:35:50 AM EDT

[#4]

Quote History

Quoted:
Just checked what you said, it is indeed the case. 60 FPS was running on a 1/60 shutter speed (set by auto), 120 FPS was 1/125(set by auto).
Doubling the light isn't possible, and I'm guessing no amount of changes to the settings will improve things if lighting is the issue on 120p.

Maybe I could just increase the shutter speed some at the loss of some brightness to decrease the blur on 60p, I'm not getting the same noise penalty at 1/125 shutter speed on 60p as I am on 120p, but the brightness is about the same. I also have a 1/90 and 1/100 speed options between 1/60 and 1/125 on 60p.

The noise at 120p isn't terrible, but it does make the image less clear than the last generation Sony camcorder I was using last year, albeit a lesser frame rate. The blur on 60p at 1/60(auto) isn't really that bad either, I'm just trying to find the optimal settings.
Losing slow motion isn't really too big of a deal, I was only going to slow down shots on goal as a replay after the shot, or questionable calls by the ref.

I suspect, unless the game is in full daylight I will just keep it at 60p auto shutter, but I might as well test some of the settings just in case.

Thanks for the help! I was scratching my head about this one, not a big photography guy.

View Quote

What you need to wrap your head around is how camera exposure works.

You're seeing the same noise at the same shutter speed because it's using the same ISO, regardless of the frame rate.

So...quick primer on camera exposure then.

You have 3 primary variables - aperture, shutter speed, ISO.

Aperture is the lens opening, this controls how much light actually gets into the camera, some cameras have a fixed aperture (like gopros) others it is adjustable. I googled your camera, seems it can do f/2 to f/11 or thereabouts, so you've got some control. As an example, f/2 lets in a lot of light. f/4 lets in waaaaaaaaaaaay less light. f/11 lets in just a tiny bit of light in comparison to f/2.

Shutter speed controls how long the sensor is exposed to light...so like 1/60 is half the speed of 1/125, so it also means ~~half~~ double the light gets in.

ISO controls how much gain is applied, more or less. People refer to it as making the sensor more sensitive to light but that's not entirely accurate. It also moves in increments of double or half the light.

ISO 100 to ISO 200 is double the gain, so you can use twice as much shutter for freezing motion, but you trade off gaining some noise.

If we want to talk in comparisons...let's pretend your camera is a bucket. The aperture tells us how big the water hose that's filling it is aka the maximum amount of water (light) that can pass through at any given time. Changing this means your hose will pass less or more water through over a fixed period of time. The shutter speed is the water valve, opening for a specific amount of time. This can be faster or shorter, passing more or less water (light) depending on the aperture.

The ISO would be like adding some rocks or something to the bucket to artificially raise the water level. It has no actual impact on the water that comes into the bucket, it doesn't care...at all. What it does is change how you perceive the water that's physically in the bucket.

Changing one of these often requires changing the others to maintain balance.

Your camera likely has several automatic or semi automatic modes to help with this until you're feeling more comfortable.

We're happy to help you out here in the photo forum!

Posted: 12/10/2018 1:46:34 AM EDT

[#5]

Quote History

Quoted:
What you need to wrap your head around is how camera exposure works.

You're seeing the same noise at the same shutter speed because it's using the same ISO, regardless of the frame rate.

So...quick primer on camera exposure then.

You have 3 primary variables - aperture, shutter speed, ISO.

Aperture is the lens opening, this controls how much light actually gets into the camera, some cameras have a fixed aperture (like gopros) others it is adjustable. I googled your camera, seems it can do f/2 to f/11 or thereabouts, so you've got some control. As an example, f/2 lets in a lot of light. f/4 lets in waaaaaaaaaaaay less light. f/11 lets in just a tiny bit of light in comparison to f/2.

Shutter speed controls how long the sensor is exposed to light...so like 1/60 is half the speed of 1/125, so it also means half the light gets in.

ISO controls how much gain is applied, more or less. People refer to it as making the sensor more sensitive to light but that's not entirely accurate. It also moves in increments of double or half the light.

ISO 100 to ISO 200 is double the gain, so you can use twice as much shutter for freezing motion, but you trade off gaining some noise.

If we want to talk in comparisons...let's pretend your camera is a bucket. The aperture tells us how big the water hose that's filling it is aka the maximum amount of water (light) that can pass through at any given time. Changing this means your hose will pass less or more water through over a fixed period of time. The shutter speed is the water valve, opening for a specific amount of time. This can be faster or shorter, passing more or less water (light) depending on the aperture.

The ISO would be like adding some rocks or something to the bucket to artificially raise the water level. It has no actual impact on the water that comes into the bucket, it doesn't care...at all. What it does is change how you perceive the water that's physically in the bucket.

Changing one of these often requires changing the others to maintain balance.

Your camera likely has several automatic or semi automatic modes to help with this until you're feeling more comfortable.

We're happy to help you out here in the photo forum!

View Quote View All Quotes

View All Quotes

Quote History

Quoted:

Quoted:
Just checked what you said, it is indeed the case. 60 FPS was running on a 1/60 shutter speed (set by auto), 120 FPS was 1/125(set by auto).
Doubling the light isn't possible, and I'm guessing no amount of changes to the settings will improve things if lighting is the issue on 120p.

Maybe I could just increase the shutter speed some at the loss of some brightness to decrease the blur on 60p, I'm not getting the same noise penalty at 1/125 shutter speed on 60p as I am on 120p, but the brightness is about the same. I also have a 1/90 and 1/100 speed options between 1/60 and 1/125 on 60p.

The noise at 120p isn't terrible, but it does make the image less clear than the last generation Sony camcorder I was using last year, albeit a lesser frame rate. The blur on 60p at 1/60(auto) isn't really that bad either, I'm just trying to find the optimal settings.
Losing slow motion isn't really too big of a deal, I was only going to slow down shots on goal as a replay after the shot, or questionable calls by the ref.

I suspect, unless the game is in full daylight I will just keep it at 60p auto shutter, but I might as well test some of the settings just in case.

Thanks for the help! I was scratching my head about this one, not a big photography guy.

What you need to wrap your head around is how camera exposure works.

You're seeing the same noise at the same shutter speed because it's using the same ISO, regardless of the frame rate.

So...quick primer on camera exposure then.

You have 3 primary variables - aperture, shutter speed, ISO.

Aperture is the lens opening, this controls how much light actually gets into the camera, some cameras have a fixed aperture (like gopros) others it is adjustable. I googled your camera, seems it can do f/2 to f/11 or thereabouts, so you've got some control. As an example, f/2 lets in a lot of light. f/4 lets in waaaaaaaaaaaay less light. f/11 lets in just a tiny bit of light in comparison to f/2.

Shutter speed controls how long the sensor is exposed to light...so like 1/60 is half the speed of 1/125, so it also means half the light gets in.

ISO controls how much gain is applied, more or less. People refer to it as making the sensor more sensitive to light but that's not entirely accurate. It also moves in increments of double or half the light.

ISO 100 to ISO 200 is double the gain, so you can use twice as much shutter for freezing motion, but you trade off gaining some noise.

If we want to talk in comparisons...let's pretend your camera is a bucket. The aperture tells us how big the water hose that's filling it is aka the maximum amount of water (light) that can pass through at any given time. Changing this means your hose will pass less or more water through over a fixed period of time. The shutter speed is the water valve, opening for a specific amount of time. This can be faster or shorter, passing more or less water (light) depending on the aperture.

The ISO would be like adding some rocks or something to the bucket to artificially raise the water level. It has no actual impact on the water that comes into the bucket, it doesn't care...at all. What it does is change how you perceive the water that's physically in the bucket.

Changing one of these often requires changing the others to maintain balance.

Your camera likely has several automatic or semi automatic modes to help with this until you're feeling more comfortable.

We're happy to help you out here in the photo forum!

There is a noticeable difference in noise at 1/125 shutter speed between the 60 frames and 120 frames modes. You saying there shouldn't be any makes me feel like I can minimize the amount of noise I am seeing at 120p down to the 60p level when 60p is at the same shutter speed, somehow.
Does that mean the camera must be changing something else? I've been playing around with some of the things you mentioned above, like the gain limit and the iris, usually all I accomplish is making the image very dark, but still with noise.

60p at 1/125 shutter

Attached File

120p at 1/125 shutter

Attached File

But, I can't check the ISO because the camcorder doesn't have a setting called that.

Here are my relevant menu screens. (I don't actually have the manual settings set to on, I just switched some on so you could see how they are quantified. (sorry for the huge out of focus images).

2.8 is the lowest this goes, at least on 60fps.

Exposure I only get a sliding scale on, no numbers.

Posted: 12/10/2018 1:54:33 AM EDT

[#6]

If there's a GAIN setting you can play with, that might well stand in for the ISO.

I saw shutter speed and iris (aperture) so remember, small number = big aperture (f/2.8) big number = small aperture (f/11) so...big one = more light.

Shutter speed is kinda the opposite, small number on bottom = slow, so it's more light (1/25) , big number on bottom is fast, so less light (1/250)

Posted: 12/10/2018 2:43:30 PM EDT

[#7]

After looking at your manual there don’t seem to be many options for you on this other than the lower frame rate with the longer shutter speed (or more light).

https://www.sony.com/electronics/support/res/manuals/4586/45865231M.pdf

Posted: 12/11/2018 6:05:12 PM EDT

[#8]

Yep, common thing for cameras is to double the framerate as the denominator for the shutter speed.

30FPS should be shot at 1/60", 60FPS at 1/120" and 120FPS should be at 1/240".

Posted: 12/14/2018 12:38:40 PM EDT

[#9]

Quoted:
120 frames was recording at 60Mbps, I do have the option to set it to 100Mbps.
60 frames was recording at 50Mbps.

View Quote

I would say bit depth is the problem. High ISO carries more noise, and that also make the image compression harder, and easier to max out bit depth.

Posted: 12/14/2018 9:32:01 PM EDT

[#10]

I see classic noise artifacts at those higher frame rates, leading me to the conclusion that it's jacking the ISO for the higher rates, and that's boosting the noise.

I've found that for an equivalent ISO, my GoPro Hero 6 is MUCH noisier than the D500.

Posted: 12/14/2018 9:44:58 PM EDT

[#11]

Quote History

Quoted:
I see classic noise artifacts at those higher frame rates, leading me to the conclusion that it's jacking the ISO for the higher rates, and that's boosting the noise.

I've found that for an equivalent ISO, my GoPro Hero 6 is MUCH noisier than the D500.

View Quote

This is because ISO settings are not interchangeable between cameras and also the gopro has a tiny sensor in comparison to that in the D500.

Posted: 12/17/2018 4:51:11 PM EDT

[#12]

Thanks for all the input, guys. I'm going to try and get a full daylight comparison test for the two frame rates, sometime this week, if the weather holds out for me. I'm hoping that full or partly cloudy daylight I can get the same sharpness as 60p on the 120p setting. It is kind of frustrating not getting the full manual control settings, like ISO, on a $1000 camcorder. Will report back with results.

[ARCHIVED THREAD] - Any ideas on the differences in image quality between 120fps and 60fps

General » Photography & Photoshopping

Warning

Confirm Action

About AR15.COM

Stay Connected

Newsletter

Contact Us