topic Re: pixels, dithering in Point & Shoot Digital Cameras

pixels, dithering

musicus — Mon, 22 Mar 2021 23:43:04 GMT

I have taken some pix with my Powershot SX170 and they have much pixelization even tough it's an

outdoors pic and there shouldn't be a problem with the clarity. The settings I used are Auto and Live.

Why am I not getting a clear, clean photo? Thanks.

Re: pixels, dithering

kvbarkley — Tue, 23 Mar 2021 02:40:51 GMT

Post it here. What are the pixel dimensions? Could you have set a small image size?

Re: pixels, dithering

musicus — Tue, 23 Mar 2021 05:27:27 GMT

Here are the 2 pix,

Resolution is 188 pixels, width 488, height 313:

Re: pixels, dithering

rs-eos — Tue, 23 Mar 2021 12:39:34 GMT

What are the pixel dimensions of your original image though?

The immediate thing I see is that the dynamic range in the scene is far beyond what your camera (and most cameras) would be capable of. So the overexposed areas are adding quite a bit of blooming.

Re: pixels, dithering

kvbarkley — Tue, 23 Mar 2021 14:16:59 GMT

If that 488 by 313 is right out of the camera, you have it set for a small image size.

If you are in movie mode, some cameras simply use a video frame in that mode. Make sure your camera is set to AUTO or P.

Re: pixels, dithering

musicus — Tue, 23 Mar 2021 15:30:36 GMT

OK, so how would I set it for a normal landscape range?

Re: pixels, dithering

musicus — Tue, 23 Mar 2021 15:35:44 GMT

I thought that if I'm shooting a movie, then I should be in MOVIE mode. You're saying that AUTO is better?

You might have a point here, because I've shot in MOVIE mode and have noticed the results are quite granular. Especially in movies shot inside my house. Are you saying I should avoid MOVIE mode? If so, why does the camera have MOVIE mode? Looking forward to your reply.

Re: pixels, dithering

rs-eos — Tue, 23 Mar 2021 15:37:27 GMT

Not sure what you're asking.

In terms of ensuring the captured image size is of the highest resolution, see page 36 in the User Manual.

Page 129 mentions the resolutions for each choice. With S (small) being only 640 x 480 (less than 1 MP) and L being 4608 x 3456 (approx 15 MP).

Re: pixels, dithering

rs-eos — Tue, 23 Mar 2021 15:40:20 GMT

AUTO is independent of capturing movies or photos. AUTO means that your camera will make all the decisions.

Let's back a bit though... are you capturing still images from movies? If so, the camera will at most shoot HD (approx 2 MP), but due to many limitations in consumer equipment, your HD stills will be nowhere near HD produced by professional equipment.

If you are capturing still images, see above user manual reference and ensure your camera is not set to capture low-resolution images.

Re: pixels, dithering

musicus — Tue, 23 Mar 2021 15:45:29 GMT

Just to clear up, I'm not referring to captured images from movies, although I do that from time to time.

I'm referring to two things:

1. Still images (in PORTRAIT or AUTO mode) that are coming out way too pixelated.

2. Movies (in MOVIE mode) that are shot in decent lighting that are also way too pixelated.

May I add that I am not an expert and therefore I just want to rely on the camera's basic settings.

At least I want to choose the best correct setting.

Re: pixels, dithering

rs-eos — Tue, 23 Mar 2021 15:56:04 GMT

We really need to know though _what_ resolution settings you are using.

For photos, see the above user manual reference. What, specifically is the setting you are using? L, M1, M2 or S?

For video, your camera has two settings: HD or VGA. And I was mistaken above that HD would be 1920 x 1080. Your camera's HD is 1280 x 720 (less than 1 MP) and VGA I believe is 640 x 480 (same resolution as for still images of size 'S').

If your resolution of your stills/movies is too low, that would definitely be one factor in the low quality you are seeing.

Re: pixels, dithering

musicus — Tue, 23 Mar 2021 18:41:34 GMT

I am looking at "Number of 4:3 Shots per Memory Card". What do I press on the camera to see

the resolution amount?

Re: pixels, dithering

musicus — Tue, 23 Mar 2021 18:43:02 GMT

Still trying to figure out what to press on the camera to

"ensure your camera is not set to capture low-resolution images."

Re: pixels, dithering

rs-eos — Tue, 23 Mar 2021 19:38:52 GMT

As I posted before, please see page 36 in the user manual (link provided in that post).

What is the size setting for your photos? L, M1, M2 or S?

What is the resolution setting for your videos? HD or VGA?

Re: pixels, dithering

musicus — Tue, 23 Mar 2021 20:07:25 GMT

Good, thank you, now I see the difference between the L, M1, M2 and S. Do I assume the

setting stays the same after I turn on the camera later? (I'll check on the HD or VGA later.)

Re: pixels, dithering

kvbarkley — Tue, 23 Mar 2021 20:32:31 GMT

Yes it does remember the setting.

Re: pixels, dithering

musicus — Tue, 23 Mar 2021 21:44:18 GMT

Just to clarify, you are saying that stills are determined by the L, M1, M2, S settings. Good. Then are video settings

then determined by HD or VG? If so, can we say that the graininess on my videos is determined by the lighting?

I have decent interior lighting (I might be wrong on this) beefed up with a Godox LED spotlight but the spotlight seems to make no difference on the video graininess. The vids are online (YT). Should I link to one of them here so you can see it?

Re: pixels, dithering

rs-eos — Tue, 23 Mar 2021 23:16:30 GMT

For photos, unless you always plan to have very tiny versions uploaded to the web, there's no reason to use the 'S' (small setting). It's best to capture L (large); giving you the most flexibility later.

For video, you camera can either shoot in HD (1280 x 720) or VGA (640 x 480). Yes, please provide links.

One guess is that if you shot in either of those (especially VGA), then scaled it up to 1920 x 1080, that would certainly explain things.