8mp vs 3mp image comparison

[ekbrewer]

hello,
I have an 8mp 1/1.8" sensor PCI-T18F2S on the top and 3mp 1/3" sensor DS-2CD2132F-IS on the bottom. Both cameras are 2.8mm and the cereal box is at 15 feet in both cases. I would expect a much better image from the 8mp. What do you think? I'm sure you would like to have a lot more camera information, but I'm not sure what would be needed...
Thanks, Eric

 

[TonyR]

Are those camera-generated snapshots?
What is the image size (like 1920 x 1080, etc.) of each camera image depicted above?
Looks like your image editor has each image digitally zoomed a lot so depending on the image size and the degree that it's zoomed will show such pixelation.

 

[mat200]

hello,
I have an 8mp 1/1.8" sensor PCI-T18F2S on the top and 3mp 1/3" sensor DS-2CD2132F-IS on the bottom. Both cameras are 2.8mm and the cereal box is at 15 feet in both cases. I would expect a much better image from the 8mp. What do you think? I'm sure you would like to have a lot more camera information, but I'm not sure what would be needed...
Thanks, Eric

View attachment 126839

View attachment 126840

See the DORI section of the cliff notes to calculate pixels on target at that range, as well as the IPVM camera calculator

Also remember, tuning parameters affect the quality of the image ..

 

[ljw2k]

I would do some more homework in regards to digital zoom and optical zoom and look at the DORI charts.

 

[sebastiantombs]

And remember this is real world, not Hollyweird with a special effects department and multiple cameras on the same scene.

 

[bigredfish]

Agree with all the above. Looks like digital zoom which only works on TV shows.

I would also check your bitrate on the 8MP camera. You would want at least 8192 if not higher.

 

[wittaj]

It is why we say do not chase MP.

Focal length for the distance to be covered is much more important than MP.

But at 15 feet, the full image looks better. But as others have said, digital zoom only works in the movies and TV. You can get away with a little digital, but not much.

And as others said, it appears you probably have too low bitrate and some other parameters that could improve it.

See this thread:

The Importance of Focal Length over MP in camera selection

At the urging of several folks here, I created a thread to show the importance of focal length and how focal length can be more important than megapixels (MP). I mentioned some of this in the post regarding The Hookup’s latest video demonstrating different cameras, including one sold from a...

ipcamtalk.com

 

[bigredfish]

Could also be sharpness, DNR, or a number of settings.

 

[ljw2k]

All my camera's are the same when digitally zoomed in @800% like you are doing.

 

[TonyR]

Looks like your image editor has each image digitally zoomed a lot so depending on the image size and the degree that it's zoomed will show such pixelation.

All my camera's are the same when digitally zoomed in @800% like you are doing.

Yep.

 

[ekbrewer]

Are those camera-generated snapshots?
What is the image size (like 1920 x 1080, etc.) of each camera image depicted above?
Looks like your image editor has each image digitally zoomed a lot so depending on the image size and the degree that it's zoomed will show such pixelation.

The images are from Blue Iris. I had double clicked on the motion detection alert clip and then used the snapshot button.
The 3mp image resolution is 2048x1536 and the 8mp image is 3840x2160.
Based on previous work with my 4/3 olympus camera, I had expected to have better resolution when zoomed in on the 8mp vs 3mp.
Eric

 

[bigredfish]

You might, if you address all of the variable settings described above

 

[wittaj]

You might have to forget what you know about DSLR and high end photography cameras LOL as you play with these. Almost everyone that has come here with experience in DSLR cameras struggle with these cameras. Every one of these cameras have more processing of the images than a DSLR camera. Some are worse than others. Then there is the compression of the video, etc. Turn off NR on one of these cameras and you will see how much processing is used.

You will find a BIG difference between photography equipment and these cameras. Things like trying to match focal lengths are tough because it may be crystal clear on high end DSLR and not be clear with these types of cameras. Digital zoom works better on DSLR cameras than these. The sensors and optics just are not at the same level. These cameras are designed for 24/7 use with abuse from the elements. DSLR cameras are designed for a different working environment and purpose. Hang a DSLR camera outside and see how long it lasts LOL! But the quality would be better for the time it was working (but also a lot more storage needed too).

Remember these are surveillance cameras, not DSLR cameras, so you have to check your expectations. For example, you can see individual hairs and skin pores with DSLR photography equipment and you won't with these kinds of cameras. These are for a different use and different expectations.

• Sensor Size - a full frame DSLR sensor size is 864mm^2; whereas a 1/2.8" sensor popular on many cameras would be 20mm^2, so the "real" camera can collect over 40 times more light than a surveillance camera. And this doesn't even account for less light available for an 8MP versus 2MP for the same size sensor.
• Shutter Speed (Exposure) - Taking a picture with a "real" camera, you can slow the shutter down to 1/2s or longer for a nice clean picture of a person not moving. Perps rarely stand still and we need a shutter of at least 1/60s to minimize the blur.
• Aperture - With a "real" camera you focus on a specific part of the field of view, while a surveillance needs to focus on things in the foreground and background, which means the aperture is smaller, further compounding the light issue.
• Compression - A single 8MP image from a "real" camera could be upwards of 5MB of storage. In surveillance cameras, if you record at 15FPS, every second of video could be 75MB or more, which could equate to 6.5TB per day per camera. Obviously most are not going to have that kind of storage, so lossy compression algorithms are used to reduce storage and network bandwidth requirement, and that can add noise.
• Environment - a "real" camera is used mainly under ideal conditions, whereas a surveillance camera is going 24/7 in every type of element, so the design and size impacts its capabilities.

 

[ekbrewer]

See the DORI section of the cliff notes to calculate pixels on target at that range, as well as the IPVM camera calculator

Also remember, tuning parameters affect the quality of the image ..

Have started reading through the cliff notes again. I had done this a couple months ago, but going through them again now, I am learning more and things are making more sense, as I build up my knowledge. I had missed the IPVM calculator before. Am playing around with it now and loving it. Wish I hadn't missed it before.
Thank you!

 

[ekbrewer]

Agree with all the above. Looks like digital zoom which only works on TV shows.

I would also check your bitrate on the 8MP camera. You would want at least 8192 if not higher.

I've got 4096 on the 8mp camera with 265 (non +). Had evaluated that vs 8192 for a couple days and couldn't tell a difference, so went with the lower. The 3mp camera is set at 3072 264 (non +).
Thanks, Eric

 

[wittaj]

Have started reading through the cliff notes again. I had done this a couple months ago, but going through them again now, I am learning more and things are making more sense, as I build up my knowledge. I had missed the IPVM calculator before. Am playing around with it now and loving it. Wish I hadn't missed it before.
Thank you!

Keep in mind though that the DORI and IPVM calculator are kinda like MPG estimates on a car - all of these are under ideal conditions.

At night, you will want to probably cut the DORI numbers in half or more. The manufacturer makes those distance claims under ideal conditions that probably are not going to work to try to capture motion at night.

While the IPVM calculator is a neat tool, once you get much beyond 30 feet or so, don't expect the quality you see for the image.

 

[ekbrewer]

It is why we say do not chase MP.

Focal length for the distance to be covered is much more important than MP.

But at 15 feet, the full image looks better. But as others have said, digital zoom only works in the movies and TV. You can get away with a little digital, but not much.

And as others said, it appears you probably have too low bitrate and some other parameters that could improve it.

See this thread:

The Importance of Focal Length over MP in camera selection

At the urging of several folks here, I created a thread to show the importance of focal length and how focal length can be more important than megapixels (MP). I mentioned some of this in the post regarding The Hookup’s latest video demonstrating different cameras, including one sold from a...

ipcamtalk.com

Thank you for the info. I had heard the warnings about chasing MP. In the end, I went with 8mp as a way of future proofing. I was thinking that the 1/1.8" sensor size was pretty decent so given other things equal, the 8mp would be better than the 4mp (except know that 4mp would be better at night.) I still need a few more cameras and would be happy to go with 4mp to save money if the 8mp really isn't going to look that much better.

 

[wittaj]

Thank you for the info. I had heard the warnings about chasing MP. In the end, I went with 8mp as a way of future proofing. I was thinking that the 1/1.8" sensor size was pretty decent so given other things equal, the 8mp would be better than the 4mp (except know that 4mp would be better at night.) I still need a few more cameras and would be happy to go with 4mp to save money if the 8mp really isn't going to look that much better.

Many here are of the opinion that 4MP on the 1/1.8" sensor is the best all around value for the money.

But again it also depends on the distance you are trying to cover, especially at night.

So far my 2MP cameras have been the money shot for every incident my neighborhood has had. Beating out my 4MP and 8MP on ideal MP/sensor ratios (granted the perps didn't get into the sweet spot distance range for those cameras, but the 2MP was just fine for the police to ID and apprehend the perps).

 

[ekbrewer]

Many here are of the opinion that 4MP on the 1/1.8" sensor is the best all around value for the money.

But again it also depends on the distance you are trying to cover, especially at night.

So far my 2MP cameras have been the money shot for every incident my neighborhood has had. Beating out my 4MP and 8MP on ideal MP/sensor ratios (granted the perps didn't get into the sweet spot distance range for those cameras, but the 2MP was just fine for the police to ID and apprehend the perps).

Here is what my property looks like. I haven't signed up for ipvm yet, so am limited to 2 cameras. I actually have four 2.8mm cameras, all mounted at doors. I generally just like to see what is going on at the property. See what cars are coming and going; what people are using the doors and when. See what the chickens are doing. Generally the cameras are positioned so that if someone comes to a door I can make out their face pretty well. I also have a "24/7 video" sign at each door. Between the signs and the cameras, I'm hopefully providing some deterrence of someone who may want to break in.

 

[bp2008]

I would expect a 1/1.8" sensor behind a 2.8mm lens to have a wider view angle than a 1/3 sensor behind the same 2.8mm lens. Wider view angles eat up the benefit of more pixels really quickly.