Specifications, Native Capabilities and Image Quality

[niko]

You're quite right that Pavle is very much on top of these things. I'm still a wet-behind-the-ears newbie so I pretty much lean on everybody for everything but I'm trying to take my first baby steps! My questions arise from my experience buying an SJCam SJ4000 Wi-Fi. They claimed an image size of 12 MP but that was only achieved by interpolation. They also claimed 720p at 60fps but didn't explain that was double frame rate. I'm just an average consumer with no expertise in optics, electronics or cameras and no particular knowledge of photography beyond enjoying it. But now my curiosity has been piqued, hence the questions here and many more in the SJ4000 thread.

Cheers

@Mtz has a useful and informative thread explaining some points:
The list of shame fake 4K cameras and CMOS size

 

[TeriTerryTarry]

This is common marketing tactics many vendors / manufacturers use in order just "to get rid of their supa-dupa product" and take your money.

How true niko!

Let me ask you a separate but related question. The bricks-and-clicks seller I bought the camera from answered many of my inquiries incorrectly (as did the manufacturer). How do manufacturers ensure sellers are properly informed of a product's capabilities and trained on its operation? Do they hold training seminars at professional conferences? Interactive online training? Perhaps in-person training at corporate headquarters of big retailers that sell a large volume of cameras? Just curious.

 

[TeriTerryTarry]

@Mtz has a useful and informative thread explaining some points:
The list of shame fake 4K cameras and CMOS size

Thanks very much niko. I just had a look at it and I'll definitely be referring back to it again.

 

[niko]

How true niko!

Let me ask you a separate but related question. The bricks-and-clicks seller I bought the camera from answered many of my inquiries incorrectly (as did the manufacturer). How do manufacturers ensure sellers are properly informed of a product's capabilities and trained on its operation? Do they hold training seminars at professional conferences? Interactive online training? Perhaps in-person training at corporate headquarters of big retailers that sell a large volume of cameras? Just curious.

I could give you some sort of answer here from my personal experience by dealing with different manufacturers, but this would not be full and some information may be a speculative due to many 3rd parties involved into info-sharing process. Some time you don't even know who you really speaking to, is he/she is just a small reseller, trading company or manufacturer.
Best is to wait @jokiin answer.

 

[niko]

Thanks very much niko. I just had a look at it and I'll definitely be referring back to it again.

No problem.

 

[Module 79L]

You're right but not every average consumer is going to take the time to look at every Techmoan action cam video or even know that they exist.

Well, do you know how I found him? When I googled "dashcams" his G1W's video review was one of the first. Everyone uses Google to search things nowadays, so it's pretty easy to find him. Plus, once people visit his YT channel they can choose the action cam video reviews they want, according to what they're interested to know about the performance of a specific model or models. They don't have to watch all the videos.

 

[Mtz]

The Sj5000+ with the 16MP Panasonic sensor is not good as dashcam, I already tested it. Not a problem with this sensor, but was not good for dashcam usage, the day images are OK but low light images not:

The test were out of city because I was testing an action cam, the SJ5000+.

Go for a dashcam with SONY CMOS like IMX322, IMX290, IMX291 or even Omnivision OV4689.

enjoy,
Mtz

 

[jokiin]

The Sj5000+ with the 16MP Panasonic sensor is not good as dashcam, I already tested it. Not a problem with this sensor, but was not good for dashcam usage, the day images are OK but low light images not:

The test were out of city because I was testing an action cam, the SJ5000+.

Go for a dashcam with SONY CMOS like IMX322, IMX290, IMX291 or even Omnivision OV4689.

enjoy,
Mtz

I wouldn't expect any 16mp sensor to do great night video based on current technology, the pixels are too small

 

[kamkar]

not unless some one made a full frame 16 mp sensor, that might work, but it will make for a allmighty dashcam

 

[TeriTerryTarry]

The Sj5000+ with the 16MP Panasonic sensor is not good as dashcam, I already tested it. Not a problem with this sensor, but was not good for dashcam usage, the day images are OK but low light images not:

The test were out of city because I was testing an action cam, the SJ5000+.

Go for a dashcam with SONY CMOS like IMX322, IMX290, IMX291 or even Omnivision OV4689.

enjoy,
Mtz

This is absolutely fantastic stuff Mtz! I'm assisting Pavle with camera reviews and this sort of detailed testing is exactly what I want to do.

The many questions I listed above weren't really intended to find out about the Boscam - I was just using it as an example. I actually meant to elicit responses from DCT members about manufacturers' claimed specifications and whether they are a true representation of a camera's ability. Apparently the answer to that question is a definite "no" in some cases. Then going beyond claimed specs, can one determine just by looking at the information that is provided, such as brand and model number of key components, that the performance specs can't possibly be true? Finally, even if the manufacturer provides an honest set of specs, and even if the components seem good, is that enough to have a reasonable degree of certainty that the camera will work well? I suppose a good lens, sensor and chipset are all necessary but are they sufficient?

When you say that a certain sensor isn't as good and to try the others you listed, how do you know that? Does it come simply from the experience of testing so many cameras? I'm having a difficult time finding technical information about sensors and chipsets that a layman can understand. A newbie can't always tell what's accurate in reviews and what isn't. Techmoan has been mentioned and I agree his reviews are very good; I've subscribed to his YouTube channel. But even there you have people that disagree with him in comments for what seem like good reasons.

Okay, just pulling my hair out at this point!!! Thanks for your reply Mtz - it's truly appreciated.

 

[jokiin]

Techmoan provides a good overview of the functionality of cameras and you get a look at what you should expect, he doesn't get too deep into the technical aspects as it would probably go over the heads of a lot of people

for the most part people don't care how something works, that just care that it works

 

[TeriTerryTarry]

I wouldn't expect any 16mp sensor to do great night video based on current technology, the pixels are too small

This is good information jokiin. A 16mp sensor seems to be one of those things that manufacturers' trumpet about their products. That's not to say 16mp isn't good, it just isn't the be-all and end-all.

What does it mean when you say the pixels are too small and how do you know that? Does that mean that the physical size of the sensor in action cams is too small to take full advantage of so many pixels? This goes back to my question about how does one know whether a technical specification is an indicator that you'll actually end up with a good image.

I really appreciate your input jokiin.

 

[TeriTerryTarry]

Techmoan provides a good overview of the functionality of cameras and you get a look at what you should expect, he doesn't get too deep into the technical aspects as it would probably go over the heads of a lot of people

for the most part people don't care how something works, that just care that it works

Yes, that's part of Techmoan's appeal for me. At first I was part of the "don't care how" group but now I'm trying to build up my understanding. It always amazes me that your comments offer so many insights and I'm trying to glean some of that from you.

 

[TeriTerryTarry]

not unless some one made a full frame 16 mp sensor, that might work, but it will make for a allmighty dashcam

What does full frame mean? Are you talking about literal size?

 

[jokiin]

This is good information jokiin. A 16mp sensor seems to be one of those things that manufacturers' trumpet about their products. That's not to say 16mp isn't good, it just isn't the be-all and end-all.

What does it mean when you say the pixels are too small and how do you know that? Does that mean that the physical size of the sensor in action cams is too small to take full advantage of so many pixels? This goes back to my question about how does one know whether a technical specification is an indicator that you'll actually end up with a good image.

I really appreciate your input jokiin.

if you have a 1920 x 1080 grid and divide into 2 million pixels, then take that same 1920 x 1080 grid divided up into 16 million pixels you'd see that the 2 million pixel version has much larger individual squares in that grid

the 16 million pixel is really suitable for larger resolutions and can offer a much finer picture at high resolutions, the down side is such small pixels don't catch as much light so won't work as well at night

 

[TeriTerryTarry]

if you have a 1920 x 1080 grid and divide into 2 million pixels, then take that same 1920 x 1080 grid divided up into 16 million pixels you'd see that the 2 million pixel version has much larger individual squares in that grid

the 16 million pixel is really suitable for larger resolutions and can offer a much finer picture at high resolutions, the down side is such small pixels don't catch as much light so won't work as well at night

Great jokiin. Thank you. That makes perfectly good sense. Let me try to understand this further. Even though each pixel doesn't capture as much light, there are more of them. Do more pixels have a cumulative effect that partly compensates for each catching less light?

If the physical size of the grid is larger but still 1920x1080, would that also partly compensate?

Now what happens if a grid having a fixed physical size is 3840x2160 instead of 1920x1080? In my mind I'm picturing a sheet of 8-1/2" x 11" grid paper. One sheet has 1/4" squares but the other has 1/8" squares. What is the effect?

Do those questions make sense?

Thanks

 

[jokiin]

each individual pixel can only collect so much light, the larger the pixel the more surface area there is to capture light so all else being equal the larger pixels will be superior at night

 

[TeriTerryTarry]

each individual pixel can only collect so much light, the larger the pixel the more surface area there is to capture light so all else being equal the larger pixels will be superior at night

Okay, thanks jokiin.

 

[gitup]

It is not a surprise that Boscam release such camera.
I thought I know the reason why Boscam will produce similar camera as SJ5000+.

 

[kamkar]

Yeah a full frame sensor would be 35 x 24 mm, ( old 35 mm photo film ) so on such a large area there would be room for much larger pixels even if there is 16 Mp.
Full frame is only somthing we see in the new Dslr cameras, and / or maybe professional video cameras.