Action cam guides for newbies?

[Pavle]

@TeriTerryTarry Hi Tery, that sounds exciting, I will send you a message right away, to see if we can fit it somehow in our guide.

 

[Pavle]

Just wanted to update and let you know that project is doing quite well. I wrote some basic stuff and now need to learn and understand the science behind the basic operation of a camera.
Also thanks to @TeriTerryTarry there will be an online manual for SJ4000 with very concise and detailed instructions on how to operate the camera.
So, if anyone else would like to help or give a suggestion, feel free to write me a pm, or post here.

 

[Pavle]

Anyone from manufacturers representatives here (perhaps @gitup
@JooVuu @jokiin or @sjcam_official
knows perhaps to clarify the process of what happens when the shutter button is pressed. Light goes through the lens, travels through glass, shutter opens, and there we are on an image sensor. Extremely complicated things happen here, I am close to figuring that out (nearly). What happens next? Data is transferred to a processor? Are there any steps before?
What is also a role of a SOC/Chipset besides recording video/photo on to the , then compressing it and then transferring it to the memory card.
I am far from expert in this micro things, but I am trying to learn exact process my self and help others understand it as well ,by writing and illustrating in a simple way.
Any help is highly appreciate and will help in educating action cam community.

 

[jokiin]

knows perhaps to clarify the process of what happens when the shutter button is pressed. Light goes through the lens, travels through glass, shutter opens, and there we are on an image sensor. Extremely complicated things happen here, I am close to figuring that out (nearly). What happens next? Data is transferred to a processor? Are there any steps before?
.

there's heaps of YouTube videos that explain this, probably better to have something people can watch rather than read

 

[Gibson99]

digital cameras don't have shutters. even DSLRs don't have them anymore as far as i know. they just record what's being captured by the image sensor at the instant you press the button.

 

[Pavle]

there's heaps of YouTube videos that explain this, probably better to have something people can watch rather than read

I am well aware of that, I plan to make both videos and text. There are people who find reading more enjoyable. Especially non-English speaking people who can use translator to understand, etc.
Since I can not do animation or anything similar, I will probably just draw it.

digital cameras don't have shutters. even DSLRs don't have them anymore as far as i know. they just record what's being captured by the image sensor at the instant you press the button.

Actually they do. Some have mechanical shutters , some have electrical and some have bridge, roll, etc. Every camera needs something to keep sensor away from the light, so every camera has a shutter one way or another.
I was referring to digital shutter here. I think that electric sensors turn pixels on/off. When you press shutter one row after another starts to turn on at a very fast pace of course.
Perhaps manufacturers here can help us understand if it works the same way in action cameras.

 

[jokiin]

I am well aware of that, I plan to make both videos and text. There are people who find reading more enjoyable. Especially non-English speaking people who can use translator to understand, etc.
Since I can not do animation or anything similar, I will probably just draw it.

actually I meant for yourself if you wanted to learn about the processes involved but maybe there's something suitable you could use on the website also

 

[JooVuu]

What is also a role of a SOC/Chipset besides recording video/photo on to the , then compressing it and then transferring it to the memory card.
Any help is highly appreciate and will help in educating action cam community.

A SoC is a complicated thing. The simplest way to describe it is it is the 'project manager'. It makes sure the WiFi is behaving, that the image sensor is doing what it should. The only problem is the SoC only has certain capabilities itself. So for instance the Ovi 4869 can actually capture up to 180fps I believe but the A7LA75 (our chip - SOC) cant do that. As such the SoC limits it.

This is a very basic way of putting things but is in essence what happens. Hope that helps!

Dan

 

[gitup]

Anyone from manufacturers representatives here (perhaps @gitup
@JooVuu @jokiin or @sjcam_official
knows perhaps to clarify the process of what happens when the shutter button is pressed. Light goes through the lens, travels through glass, shutter opens, and there we are on an image sensor. Extremely complicated things happen here, I am close to figuring that out (nearly). What happens next? Data is transferred to a processor? Are there any steps before?
What is also a role of a SOC/Chipset besides recording video/photo on to the , then compressing it and then transferring it to the memory card.
I am far from expert in this micro things, but I am trying to learn exact process my self and help others understand it as well ,by writing and illustrating in a simple way.
Any help is highly appreciate and will help in educating action cam community.

Actually, I am not professional to explain this, the hardware engineer know this better.
Below is some basic info I found from internet.

 

[old4570]

Hmmmm . If you open up a Dashcam . you will see there is no shutter ...
The lens sits directly over the sensor .. So the sensor is constantly exposed to the light or image source ...
So any video or stills images captured are done so electronically ...
So how its done specifically ( ? ) Is it like a screen capture on a computer ( ? )

A digital SLR has a shutter , and a mirror .. Much like the 35mm SLR cameras ..
Those little compact Digital cameras and those camera phones = I doubt very much they have shutters ... ( Any of them )

 

[Gibson99]

I thought a lot of new DSLR cameras were "single lens reflex" in name only now, so they can shoot video, take photos at extremely high frame rates, and so on. Some have little LCD screens inside the "optical viewfinder" so they don't need the mirror anymore. They still use the same body and form factor so there's lots of room for a nice big sensor and they can of course use all the old lenses...

 

[old4570]

There are the Mirror Less Digital SLR cameras ..
You look at the screen at the back of the body ( much like the compacts ) and take your picture or video ..
They use the sensor , much like the normal SLR in live view ( mirror lock up mode - Live View ) ..
Pentax K30 onward offer Live view ( I think its K30 for Pentax ) ..
I have used Live view a few times when doing macro photography , as my back will only bend and twist so much ...
Makes life a little easier , and there is a whole bunch of people out there now that like viewing the LCD screen , so the camera makers are offering SLR without viewfinder and mirror ..
Also makes life easier for the manufacturer ( Cheaper + less QC issues = That mirror can be a PITA some times )

 

[Pavle]

actually I meant for yourself if you wanted to learn about the processes involved but maybe there's something suitable you could use on the website also

Sorry Rick, I misunderstood completely. Indeed there are many videos, but non of them explains how it works in an a.cam. It is quite sad that in 2010-2012 so many useful videos were posted on how camera works topic. Last few years, not many people are willing to go in-depth and explain these things with newer cameras. I guess they are busy being "viral" goofing around.

A SoC is a complicated thing. The simplest way to describe it is it is the 'project manager'. It makes sure the WiFi is behaving, that the image sensor is doing what it should. The only problem is the SoC only has certain capabilities itself. So for instance the Ovi 4869 can actually capture up to 180fps I believe but the A7LA75 (our chip - SOC) cant do that. As such the SoC limits it.

This is a very basic way of putting things but is in essence what happens. Hope that helps!

Dan

Thanks Dan, it certainly helps a lot. Appreciate your reply, if you think of something else that might help in this research, please post it when you have the time.

Actually, I am not professional to explain this, the hardware engineer know this better.
Below is some basic info I found from internet.
View attachment 19379
View attachment 19380

Thanks Bill, interesting image.

I understand this is quite complicated to explain especially for non-engineers(like most of us here I believe), so if any of you guys know something more that can be helpful to explain the process of capturing an image/video with specifically an action cam, how its components work and communicate together, it would be great if you can share it with us here.

 

[jokiin]

Sorry Rick, I misunderstood completely. Indeed there are many videos, but non of them explains how it works in an a.cam. It is quite sad that in 2010-2012 so many useful videos were posted on how camera works topic. Last few years, not many people are willing to go in-depth and explain these things with newer cameras. I guess they are busy being "viral" goofing around.
.

the performance may have improved but there's really no technical advances that would change things from information from 2010 really

 

[old4570]

This is a nice video ( SLR though )

 

[Pavle]

All these SLR and DSLR tutorials are clear to me. I understand nearly all parts.
But action cameras are different. They are somewhere a mixture of point and shoot cameras and DSLR. They do not have all these parts.

Am I right when I say that action cameras use rolling shutter? Do manufacturers have this kind of information? Or is it a global shutter?

 

[jokiin]

Am I right when I say that action cameras use rolling shutter? Do manufacturers have this kind of information? Or is it a global shutter?

rolling shutter is CMOS, global shutter is CCD

 

[Gibson99]

rolling shutter is CMOS, global shutter is CCD

oh, there's a whole other can of worms... whether cmos or ccd is better. there's an obvious cost difference from what i understand (cmos is cheaper and uses less power), but there's other considerations, too. i think most if not all space-based imagers today use CCD for their speed, durability and reliability (considering how much radiation there is in space). the new horizons craft that blasted past pluto at something like 36,000 mph or 57,000 km/h. to put that in perspective, a bullet fired from a pistol travels at around 650-750 mph (1050-1200 km/h). the speed of sound (in air) is 767 mph or 1235 km/h. so the fact that new horizons captured as many detailed photos as it did at that speed is pretty awesome. anyway, New Horizons uses CCDs for its imagers.

 

[jokiin]

I think for our use CMOS is the better solution right now, things may change though, technology is always on the move

 

[TeriTerryTarry]

For those with the background and inclination there are many fascinating, free online courses offered by top educational institutions all over the world. I've already looked into them for my own work specialization (not action cams or anything electronic!) and found some of them to be very helpful. Whether or not they have anything that might prove useful in this endeavor I'm not sure but I'll post the links here anyway.

http://www.oeconsortium.org/
http://oli.cmu.edu/
http://ocw.mit.edu/index.htm

Cheers