Looking for advice of Camera and Software

[wittaj]

Sure if you throw enough infrared on it, it can make a difference, but then you are adding external infrared.

Don't go by the distances they claim the infrared can be seen - that is perfect situation with a wide open shutter and an object not moving.

Regarding minimum illumination, Many do not pay attention to the minimum illumination specs...because those are under ideal situations with so many factors not known.

Almost every camera will say 0 LUX with infrared or white LED on, and we all know how poorly Reolinks perform at night in low light yet that is their spec....or even two different good cameras. The 5442 4MP2.8mm fixed lens camera will beat the socks off the 5241 2MP 2.8mm fixed lens or a Reolink and they both say 0 Lux with IR on.

Heck darn near every camera will say 0 LUX with IR on....

Once upon a time manufacturers would at least say at what shutter speed that rating was based on. Most would say a 1/3 shutter. That is way to slow for anything. You need to run minimum 1/60 shutter to start to minimize blur.

But now they don't even provide that, so in most cases it is a wide open iris, slowest shutter the camera allows, and gain and brightness cranked to 100 so that they can get the lowest illumination number possible.

But nobody would run the camera in that configuration.

Some of the older cameras would give these kind of specs so you knew how the camera was setup to come up with the minimum illumination.

0.002Lux/F1.5 ( Color,1/3s,30IRE)
0.020Lux/F1.5 ( Color,1/30s,30IRE)
0Lux/F1.5 (IR on)

So of course, the faster the shutter, the more light that is needed.

To minimize blur with motion, you need to run a shutter at at least 1/60 shutter - once you start doing that, the LUX specs are out the window.

But as more competition came out, manufacturers started playing games and tweaking the settings for getting the lowest lux possible, but that came at a cost of a configuration nobody would use. So they wouldn't say how the camera was configured to capture that minimum illumination rating.

They play these marketing games to make it look like the camera is better than it is for someone that is just chasing minimum illumination numbers. Kind of like how we rarely get the miles per gallon a car is rated for.

It is a tool, but I would prefer to see the reviews here with settings provided and make an educated guess as to if my light is more or less than the reviewer.

 

[wittaj]

Just adding to the sensor size part of the discussion: I know the below two camera angles are not the same view, but the camera pointing to my meter box and gas meter is an 8 mp on a 1/2.7" (or thereabouts) and the porch camera is 4 mp on a 1/1.8". You can clearly see all the noise in the 8 mp camera and a clearer image in the 4 mp porch camera. Both cameras are using IR and no purpose external lighting used. I can't comment on the lux numbers of camera models but I can generally accept that larger sensors with 4 mp is a damn good night-time camera.

View attachment 169300

View attachment 169301

For the rest of the world, yes, here in Australia we are already into our night-time, you guys are just waking up.

And I bet both of these cameras say 0LUX with IR

 

[agarwaldvk]

Hi Guys


Appreciate you all providing so much of valuable information to enable me to buy the right cameras. Point taken - 1/1.8 inch sensor at a minimum for a 4 MP camera. I am not looking for anything with any higher resolution as I think that this will for me.

Here are a couple of items that I have come across and I think they are reasonably good but not sure (I am not understand how they work particularly well) - can you please have a look at the general specification and advise if they are half decent cameras :-

Dome - Uniview IPC3234SA-DZK Security Camera: 4MP Dome, Pro Series, 2.8~12mm
Bullet - Uniview IPC264SA-DZK Security Camera: 4MP Bullet, Pro Series, 2.8~12mm
Turret - Uniview Security Camera: 4MP Turret, 2.8mm, Prime-III - IPC3634SE-ADF2

Thanks once again for all the information and help provided so far. Greatly appreciated. Didn't realize there is so much to know and what is not really disclosed in product details but nonetheless!


Best regards


Deepak

 

[looktall]

There is no 5MP camera on the market on the ideal MP/sensor ratio.

This is probably the best I've seen for 5mp.

NightChroma NCPT500 3K Pan Tilt PoE Security Camera - ANNKE Store

340° pan & 110° tilt, 3072*1728 resolution, acme color night vision, motion detection, etc. to see clearer details and wider range. With a wide range of applications, it is suitable for many environments, backyards, supermarkets, shopping malls, etc.

au.annke.com

Looks like a good price too.
1/1.8 sensor, pan and tilt (no zoom though).

 

[CCTVCam]

Just to make it absolutely clear, the VPN should be built into your router software so router selection is key here. An alternative is to download the VPN software to your router, assuming your model allows this, but this can be even more complictaed to set up as the built in versions are often cut down to suit the router whereas the downloaded versions are more fully fledged as they need to fit more of a range of systems. You don't need the extra bits for most routers.

I'd look for a router with a VPN built in. OpenVPN and Wireguard are 2 that are commonly found built in.

As for can a VPN be hacked? Anything can be hacked but it would be very difficult at least with current technology as the keys are random and long and the remote has to respond to the base with the correct response to be offered a connection. I've never heard of a VPN tunnel being successfully hacked and it's highly unlikley anyone who had the skill, which would be probably a Government actor, would be interested in your camera feed even if they could get in. Now if your were hosting cameras watching the NSA building or a nuclear research facility, then a state actor might consider it worth attempting. Even then it would be hard with current encryption. Your average script kiddy or bedroom hacker isn't getting into your VPN tunnel anytime soon.

 

[agarwaldvk]

Hi Guys

Back again. Sorry for the long absence but I had been trying to do some reading to better know what I am talking about.

After hearing all the technical talk from you guys, I have been reading a fair bit in my attempts to understand the parameters that drive the image quality under trying lighting conditions, for example image quality from cameras with 2MP and 4 MP resolution images with sensor sizes of 1/2.7 and 1/1.8 inch respectively.

This is what I have found in terms of light capturing capability of the sensor but am not so sure about its impact on zooming of the image on playback, hence I remain a trifle uncertain if I have got the full story.

Please feel free to contradict/correct me if I am on the wrong track as my intent is to get a better understanding in getting the right camera without spending too much money that I don't need to spend.

They say that it is the size (rather than the number) of the photosites that play a more significant role in dictating the quantity of image making light that the sensor is able to collect - resulting in better image quality in low light conditions. Therefore, a 4MP image (~2560 * 1440) on a 1/1.8" sensor (~7.18 * 5.32) mm will give an approximate photosite size of 7.18 / 2560 = 2.804 nanometer. Similarly a 2MP image (~1920 * 1080) on a 1/2.7" sensor (~5.37 * 4.07) mm will give an approximate photosite size of 5.37 / 1920 = 2.796 nanometer. Both these figures are nearly identical, hence wouldn't it be reasonable to expect an image of similar quality from either of these 2 cameras viz 4MP with 1/1.8" sensor and 2MP with 1/2.7" sensor?

So, if I am looking at a camera with 2.8 - 12 mm varifocal lens camera (for convenience of adjustment during setup), wouldn't it do the job of providing reasonably good night vision video using either.

 

[wittaj]

Hi Guys

Back again. Sorry for the long absence but I had been trying to do some reading to better know what I am talking about.

After hearing all the technical talk from you guys, I have been reading a fair bit in my attempts to understand the parameters that drive the image quality under trying lighting conditions, for example image quality from cameras with 2MP and 4 MP resolution images with sensor sizes of 1/2.7 and 1/1.8 inch respectively.

This is what I have found in terms of light capturing capability of the sensor but am not so sure about its impact on zooming of the image on playback, hence I remain a trifle uncertain if I have got the full story.

Please feel free to contradict/correct me if I am on the wrong track as my intent is to get a better understanding in getting the right camera without spending too much money that I don't need to spend.

They say that it is the size (rather than the number) of the photosites that play a more significant role in dictating the quantity of image making light that the sensor is able to collect - resulting in better image quality in low light conditions. Therefore, a 4MP image (~2560 * 1440) on a 1/1.8" sensor (~7.18 * 5.32) mm will give an approximate photosite size of 7.18 / 2560 = 2.804 nanometer. Similarly a 2MP image (~1920 * 1080) on a 1/2.7" sensor (~5.37 * 4.07) mm will give an approximate photosite size of 5.37 / 1920 = 2.796 nanometer. Both these figures are nearly identical, hence wouldn't it be reasonable to expect an image of similar quality from either of these 2 cameras viz 4MP with 1/1.8" sensor and 2MP with 1/2.7" sensor?

So, if I am looking at a camera with 2.8 - 12 mm varifocal lens camera (for convenience of adjustment during setup), wouldn't it do the job of providing reasonably good night vision video using either.

In theory, yes, but reality shows something different.

Even though two cameras may show 2.8 to 12mm, the actual field of view could be different.

Your analysis doesn't take into account the f-stop number and generally the bigger sensor has a better number.

I have both 2MP and 4MP varifocal on the appropriate MP/sensor ratio and I would recommend the few extra bucks for the 4MP. Every little bit helps and even though your nanometer numbers are close, the 4MP is better.

 

[saltwater]

I'll assume your maths are correct, but I'm sure others are better able to make comment in regards to the theory of what you're asking. I can only go by experience and compare two cameras, both Dahua, one is an 8mp on a 1.27" sensor and the other is a 4mp on a 1.18" sensor and both 2.8 or 3.6mm. I know at this point it's apples and oranges, but the night time quality of the 8mp is NOTICEABLY inferior to that of the 4 mp both under IR.

I've just seen @wittaj's comment post as I was typing this and yes the aperture is also a factor, and right now I couldn't tell you the apertures of my cameras.

After the fact, you will be able to digitally zoom in further with a 4 mp image than you can with a 2 mp image before blurry pixilation occurs.

[EDIT]: Duh, I just realized that I previously posted comparison images of what I explained above, didn't need to re-explain it, sorry everyone.

 

[agarwaldvk]

Hi Guys


Thanks for the information.

That is true - I didn't consider the F stops (that information is generally not available on the data sheet provided by most manufacturers anyway). I am sure it would have an impact on the low light capability of the camera - not sure to what extent, so I am going to get guided by you all.

So, if we were to have a camera with 4 MP image resolution with a sensor size of 1/3" (just for the sake of a discussion) with an F stop number (or maximum aperture ratio of F2.0 - which would be just 1 full F stop away from the fully open aperture, right?), wouldn't such a large aperture opening more than compensate for the smaller sensor size relative to 1/1.8" sensor? Attaching the datasheet for one of the Hanwha 4Mp bullet cameras for your immediate reference - would love your thoughts on it.

Also, if I have to place a camera on the sides of the house (on both sides) which are quite narrow and long - no more than 2 meters wide and about 13 meters long), wouldn't I need a very long focal length camera - around 12 mm or so OR can I somehow change some settings on the camera so that it doesn't look in to the neighbour's property?


Best regards


Deepak

 

[wittaj]

We have said it in this thread before and we will say it again - chase sensor size, not MP.

4MP on a 1/3" sensor is flat out a budget camera and will perform poorly at night or low light conditions (reference my post in this thread with the deer).

Your thoughts on fstop is inaccurate as well. The smaller the "F" of the lens the better the low light performance. F1.4 is better than F1.8, so you throw a 4MP on a 1/3" sensor with at fstop of 2.0 and it will perform poor in low light conditions.

As far as not getting your neighbors property in the field of view, yes a varifocal that you can optically zoom in will help, and the good cameras will allow you to place privacy masks on areas you do not want to see or record.

 

[saltwater]

Also, if I have to place a camera on the sides of the house (on both sides) which are quite narrow and long - no more than 2 meters wide and about 13 meters long), wouldn't I need a very long focal length camera - around 12 mm or so OR can I somehow change some settings on the camera so that it doesn't look in to the neighbour's property?

I have a similar narrow side, 1.8m x 15m, the below image is a fixed 6mm lens 5442 camera, rotated 90 degrees.

 

[agarwaldvk]

We have said it in this thread before and we will say it again - chase sensor size, not MP.

4MP on a 1/3" sensor is flat out a budget camera and will perform poorly at night or low light conditions (reference my post in this thread with the deer).

Your thoughts on fstop is inaccurate as well. The smaller the "F" of the lens the better the low light performance. F1.4 is better than F1.8, so you throw a 4MP on a 1/3" sensor with at fstop of 2.0 and it will perform poor in low light conditions.

As far as not getting your neighbors property in the field of view, yes a varifocal that you can optically zoom in will help, and the good cameras will allow you to place privacy masks on areas you do not want to see or record.

I don't know what makes you this aggressive with this agitated state of mind. The message that you have been trying to send is obviously not getting through.

I though that you were trying to say that sensor size is perhaps one of the more significant parameter in determining picture quality in low light conditions - which I now understand relatively well. No issues there.

Following this, I put in a fair bit of effort (I realize that it may not have been enough though), to understand the influencing parameters on image quality and put forward some information relating to the photo site size as a determining factor for picture quality, probably a good proxy for the sensor size (in my view) - which you immediately shot to pieces pointing to lack of reference to the F stop number. I inferred that to mean that no matter how big the aperture opening is, it would serve no purpose on a relatively small sensor - which I struggled to relate to (I agree I may not be anywhere near half as clever as you are). I was referring to a lens with an F stop number of F2.0 (which I thought was a fairly large aperture opening) - not too many F stops away from F1.0 (essentially 1 full F stop away from F1.4, right? I am sure you are aware that F1.8 is not 1 full F stop after F1.4, its F2.0).

I apologize for my attempts to learn a bit more of how security camera would work better under challenging lighting conditions on technical grounds by asking questions (probably more that you would have liked) - but the intent was never to question you or your knowledge. I think I get the message and will refrain from making any further requests for information and/or suggestions and/or recommendations if it causes so much of frustration to you - certainly not worth the effort in my view!

Once again, sorry!

 

[wittaj]

I don't know what makes you this aggressive with this agitated state of mind. The message that you have been trying to send is obviously not getting through.

I though that you were trying to say that sensor size is perhaps one of the more significant parameter in determining picture quality in low light conditions - which I now understand relatively well. No issues there.

Following this, I put in a fair bit of effort (I realize that it may not have been enough though), to understand the influencing parameters on image quality and put forward some information relating to the photo site size as a determining factor for picture quality, probably a good proxy for the sensor size (in my view) - which you immediately shot to pieces pointing to lack of reference to the F stop number. I inferred that to mean that no matter how big the aperture opening is, it would serve no purpose on a relatively small sensor - which I struggled to relate to (I agree I may not be anywhere near half as clever as you are). I was referring to a lens with an F stop number of F2.0 (which I thought was a fairly large aperture opening) - not too many F stops away from F1.0 (essentially 1 full F stop away from F1.4, right? I am sure you are aware that F1.8 is not 1 full F stop after F1.4, its F2.0).

I apologize for my attempts to learn a bit more of how security camera would work better under challenging lighting conditions on technical grounds by asking questions (probably more that you would have liked) - but the intent was never to question you or your knowledge. I think I get the message and will refrain from making any further requests for information and/or suggestions and/or recommendations if it causes so much of frustration to you - certainly not worth the effort in my view!

Once again, sorry!

Sorry bro - I am not agitated and didn't mean to come off aggressive and i apologize if that is the way you took it. It is great you are asking questions and trying to learn.

Simply put, a camera on a 1/3" sensor and f2.0 is a budget cam that will perform poor in low light. Look at most consumer grade, big box store cameras and that is their spec. 1/3" sensor is good for 720P regardless of fstop.

 

[agarwaldvk]

Hi Wittaj

No issues. It all comes down to perception, isn't it? No offense taken. I am a mechanical engineer by primary qualification, so I hopefully do understand the theory behind both light and lenses. Its just that I passed out a few decades ago and my primary professional activity for the last 20+ years don't involve working with lenses and lighting. Hence, it doesn't comeback to me as quickly and as naturally as it probably does to you. All good.

Again, from technical perspective, as acknowledged by one and all, the amount light that gets collected by a sensor is, among others, a function of the sensor size (proxy for total photo sites area) - true. Let's take an example and cast a certain resolution image on a 1/1.8" (reasonably large) sensor.

Now assume that :-
1. We are using lenses of different apertures to cast this same image on this same sensor and
2. The maximum aperture ratio (full F stops) goes from F1.4 (very large aperture allowing lots of light to go through) to F22.0 (very small aperture allowing a lot less light to go through)

Let's ignore the shutter speed for the minute to keep things simple and see if my understanding is flawed. I use F"X" representation for convenience instead of f/"X" for aperture - larger "X" would refer to smaller aperture.


Taking the first extreme case of using a lens with a very smaller aperture (F22.0) - with the sensor being as big as it is, it will, more likely, collect all of the available light that falls on it and probably more if more of it was available but isn't because of the small aperture.
Now, take the second extreme case of using a lens with very large aperture (F1.4) - again with the sensor being as big as it is, it will probably collect a fair chunk of the available light that falls on it but not all of it as the total photo sites area on the sensor is more likely to be not big enough to do so.

Now if we were to use a reasonably large (or small, take your pick) aperture lens (say F2.8), let's assume that the total available photo sites area on this sensor was 'more' than large enough for it to collect all of the available light that falls on it. In a scenario like this, where unused capability to collect light is available, if we were to have used a lens of larger aperture say F2.0 or even F1.4 (instead of F2.8 as we did in the example), wouldn't it be able to absorb more of the available light than it did previously and consequently produce a better image in low light conditions - everything else remaining the same - the same sensor and the same image resolution? I would think so - obviously you don't. This is where my confusion lies.

The reason for my confusion is that in the last post, you mentioned '1/3" sensor is good for 720P regardless of fstop' and in one of the earlier posts you indicated that 'my analysis doesn't take into account the f-stop number'.

Please help! Or am I on the wrong tram altogether.


Best regards


Deepak

 

[wittaj]

All good stuff.

As it relates to my comment that your analysis doesn't take into account the f-stop number, that was in reference to trying to compare a 2MP on a 1/2.7" sensor versus a 4MP on a 1/1.8" sensor and looking at the nanometer calculation that you came up with. Cameras that meet those specs are going to have better fstop numbers (f1.0 to f1.4) than consumer grade that are typically (f2.0 to f3.0).

In that first example you provided, both the 2MP and the 4MP would be on their respective ideal MP/sensor ratio sensors, so an incremental f value change can be what pushes the 4MP on the 1/1.8" sensor over the top in that example.

This camera you now provided for discussion was 4MP on the 1/3" sensor. That is far from an ideal MP/sensor ratio, so when you do your nanometer calculation, that calculation is not going to be near the nanometer calculations in your first example and no fstop number will compensate for that less than ideal MP/sensor ratio.

These sensors are tiny and when you take apart one of these cameras and see how tiny they really are, it is easy to see why you cannot get enough light on these to perform well.

So this chart shows the ideal MP/sensor ratio that experience of many here shows results in the best performance at night:



So when you take 1/3" sensor and shove 4MP worth of "pixel screen" on that tiny sensor, it simply cannot get enough light in low light conditions to make a difference. An f1.0 would still be a horrible night quality camera.

What most people don't realize is there is more "pixel screen" material on the 4MP, so two cameras of different MP on the same size sensor will result in the higher MP having more opaque "screen" material that impacts how much light gets thru. So two different cams on same sensor means the lower MP will allow more light on the sensor, so a 4MP on a 1/3" sensor will be much darker than a 720P camera on the same size sensor.

Use a Window for example. Which one is clearer to look thru - the one with a screen or one without? The more holes a screen is produced with, the more material there is as well.

These sensors are small and we need to get as much light to them as possible.

An analogy to try to understand why cameras need so much more light - let's look at an 8MP camera and this 8MP needs at least four times the amount of light as a 2MP for the same sensor. The sensor size is the same in each camera, but when you spread the "screen" of 8MP worth of pixel holes across the same sensor, it now has 4 times the holes, but also 4 times the "screen material" than the 2MP.

Kind of hard to explain, but lets try to use a window screen as an analogy - take a window where the opening is fixed - that is the sensor - you add a screen to it (that represents 2MP) and looking out through the screen is a little darker outside because of the screen material. Now replace that screen with one that has four times the amount of holes (now it represents 8MP) and it will be darker looking through it because (while the resolution would be better) there is a lot more screen material.

So if your house is like most where the top pane is glass with no screen and the bottom half is window with the screen and you see something outside during the daytime - do you sit down to look out through the screen or do you stand up to look a the object through the window with no screen?

And that is accentuated even more at night time. Look out your window with and without the screen and it will be darker looking through the screen than without it. If you are looking out your window to see the stars or the moon, do you look out the part of the window with the screen, or the upper portion without the screen material?

Now obviously as it relates to a camera, you need to balance the amount of pixel holes with the screen material - too few holes (and thus less screen material) and the resolution suffers, and too many holes (and thus more screen material) and the more light that is needed.

Look at a window screen and available meshes. The actual window opening does not change size, so that is the sensor. The screen material is the "pixel screen" that makes up the MP. Which one of these is going to let more light thru?

So if you are taking a 22 mesh screen and trying to get the same amount of brightness thru into the house as the 4 or 14 mesh screen, it will need A LOT more light.

A close comparison would be the 22 mesh screen is an 8MP and the 14 mesh is a 4MP. So if you have the same amount of light going thru a 14 mesh screen as you do a 22 mesh screen, it will be darker for the 22 mesh screen and any parameter adjustment you do to brighten it (gain, iris, brightness) will add more noise.


This is how outside sun shades work. The darker/more shade it provides, the more holes the shade has. More holes equals more screen material which means more light that is needed to penetrate it.



I have a 4MP and 2MP on the same 1/2.8" sensor and the picture quality is quite different between the two and the 2MP kicks it's butt at night.

My 4MP on the 1/1.8" sensor performs better than my 2MP on the 1/2.8" sensor. Even though they are both ideal MP/sensor ratio cameras, the larger sensor has the advantage.

Now this is where you can see the difference about can a camera run in color or B/W for two different MP cameras on the same size sensor.

In most instances, you want to get a camera that will perform at your location for the worse situation, which for most of us is at night when it is dark and there is little to no light. If a camera performs at night, it is easier to tweak settings to make it work during the day than it is the other way around.

My 2MP cameras outperform my neighbors 4K (8MP) cameras....why....because they are both on the same size sensor.

So if low light capability is what one is looking for, you want to be looking for cameras that are on the ideal MP/sensor ratio.

 

[agarwaldvk]

Oh mate. Good on you. That was exactly what I was looking for all along. Great explanation. Your efforts are sincerely appreciated.

Now I see why more light is needed. Surprising that not many camera manufacturer's provide the F stops details on their datasheets but nevertheless. I think I now know what I need to know. Thanks to you for the most part and others too in no small measure.

So in my case, if I am looking for a 2MP camera on a 1/2.7" sensor, that should do me OK. Everyone here seems to be talking Dahua cameras, in particular the 5442. I did look at that but boy there are so many variants of that with wildly varying prices. So I thought I might as well go for the 2 MP ones, maybe Uniview or Hanwha - but there aren't very many Hanwhas with 2 MP resolution. Looks like I won't be able to afford anything with a higher resolution image with a bigger sensor.

Does NDAA compliance mean much to anyone here or it's kind of a non event stuff for the mere mortals like myself?

 

[wittaj]

Yeah I think 2MP on the larger 1/2.7" sensor (compared to 1/2.8") will perform very well.

I still have many 2MP on the 1/2.8" sensor going and do a fine job. The 4MP on the 1/1.8" sensor is a better image, but I can't afford to replace every camera at once LOL.

As a homeowner NDAA means nothing to you. A year from now your system will still work and will still be allowed to be used (at least in the USA, not sure about your country).

The ban only applies to government installations. As a private homeowner you can continue to purchase and use them.

These "banned" brands are still being sold in the US and are legally allowed to except for government installations.

NDAA complaint means nothing - even NDAA cameras have been hacked.

EVERY camera is a security risk. It is why we do not give them internet access. That is the real problem that the government isn't addressing.

Here is just a sampling of the threads discussing it:

FCC to ban sales of some Chinese video products

US bans approval of new technology from China's Huawei and ZTE for 'national security

US President Signs Bill Into Law Requiring FCC To Ban Further Authorizations of Dahua and Hikvision

Today's FCC Ruling

 

[looktall]

Surprising that not many camera manufacturer's provide the F stops details on their datasheets

They usually show the aperture size in the minimum illumination details.
Eg. Min. Illumination
Color: 0.005 Lux @ (F1.2, AGC ON), 0 Lux with IR)

 

[agarwaldvk]

So, if you do not give them internet access, then how do you watch the footage when you are not home. I would have thought that would be one of the more important reasons to have the security cameras installed, isn't it?

That's where that wireguard stuff comes in, does it?

@looktall
I did see that the 'F' number in the minimum illumination section in some of the datasheets but for some reason thought that maybe its a conjured up number and doesn't really reflect the true F stop number of the camera and ignored it for all purposes. God knows for what reason but I did. So can I reasonably look there and take that to be a close enough F stop number for that camera?

 

[saltwater]

So, if you do not give them internet access, then how do you watch the footage when you are not home. I would have thought that would be one of the more important reasons to have the security cameras installed, isn't it?

That's where that wireguard stuff comes in, does it?

Yes, that's where VPN kicks in, you're accessing your home network as if you were at home. Using your network settings you can block outgoing traffic to the internet, ie. your cameras. But using your VPN, your network thinks you are within your network and therefore the blocking rules are bypassed. That's my basic understanding of the situation.

It can be a PIA at times, as I forget to turn on my client VPN and try and access Blue Iris but nothing, can't get through, catches me out a few times. Then I have to remember to turn off the client VPN.