Trouble connecting 'some' Reolink cameras

[awsum140]

A side comment on that tearing you're seeing. I have a POS 4MP camera I bought before I knew better and it turns out it's actually a Reolink. It has that same tearing effect and I have it set to 1080P, not 4K. The problem comes from the fact that there is no way to control the I frame interval. The camera, in it's "infinite wisdom", decides what the I frame interval should be and it's always far too low. That results in the tearing you see, I believe.

 

[dragoneggs]

It could be a lot of things.

The thing is: To get clear stills with no motion blur, you need a fairly fast shutter speed. But that limits how much light can reach the sensor. So the higher sensitivity sensors help with that.

I wrote a long post about all of those tradeoffs a while back. I will try to find it.

But the thing is, in general, larger individual photodetectors can gather more light, and, because they're larger, they also can have higher dynamic range because their capacitors can hold more electrons. The so-called "full well" value is greater.

These individual photosensors are so tightly packed onto the sensor ICs, that you are actually dealing with sizes so small that they can hold only a small number of electrons.

This is why for a given sensor IC size, the more "megapixels", the tinier the individual photo sensors must be. And the tinier the photosensor, the worse its light gathering capability, and the lower its full-well capacity.

So higher pixel counts can, if the optics can handle it, give better resolution. But you do trade off light sensitivity and dynamic range for this higher resolution.

That's why it is often better to use more good 2megapixel cameras than cover the area with fewer higher megapixel cameras.

There is a very old saying in photography:

"There is no free lunch".

Here it is:

I got robbed, now I'm buying cameras so I can watch them do it again

Thanks J... I understand better now.

 

[dragoneggs]

A side comment on that tearing you're seeing. I have a POS 4MP camera I bought before I knew better and it turns out it's actually a Reolink. It has that same tearing effect and I have it set to 1080P, not 4K. The problem comes from the fact that there is no way to control the I frame interval. The camera, in it's "infinite wisdom", decides what the I frame interval should be and it's always far too low. That results in the tearing you see, I believe.

Thank you. Yes, fenderman explained that Reolink doesn't have I frame interval control. Could someone explain what is I frame interval? I realize there likely nothing that can be done and I am moving to Dahua's except for a couple but curious anyways!

 

[SouthernYankee]

a simple description.
The current video compression use an Iframe. The Iframe is a complete 100% picture, all pixels. All other frames are the pixels that have changed for the Iframe. The math to make each frame is complex. What pixels to put in the frames between the Iframes is complex. So if the Iframes are to far apart, the video processor can not do a good job building the frames.

It is a balance between the amount of data that is being sent/recorded and the quality of the picture.

 

[dragoneggs]

Thanks SY, I also found this thread that helped explain it to me.

Iframe interval on Dahua cameras

 

[Q™]

Trust me, I am not worried.

​

 

[J Sigmo]

View attachment 37417​

Hah!

Hmm, I'm not sure, but does @fenderman have something against Reolink? I really can't tell.

 

[Q™]

I'm not sure

​

 

[awsum140]

That's easy to do. I routinely shut off the IR in my cameras and use external IR illuminators. All it takes is a PoE splitter or a second cable run of CAT. In one instance I have an IR illuminator about 30 feet in front of the camera that give excellent depth lighting at night in a particularly dark area, and it's only a 7 watt illuminator. The evenness of lighting plus no bug/rain/snow problems makes it well worth the added effort.

 

[J Sigmo]

The IR LEDs *should* have a cable (or be mounted on a board that has a cable) that runs behind the lens and plugs into the main board of the camera. You should be able to simply unplug that cable from the main board. A bit less permanent of a "fix". I dunno about the Reolinks, but at least Hikvisions and Dahuas have IR LEDs that can be unplugged. Of course, they also have software controls to disable the LEDs, so you don't need to unplug them anyway!

I studied this camera very well, and the same cable that carries the signal from the camera's light sensor (to switch from IR mode to color mode) carries the signal to switch the illuminators on and off. The front board has the LEDs and the light sensor on it. The only safe way for me to make this modification was to make a foil cut. Unplugging the front board switches the camera into B&W mode permanently if I recall correctly. And their stupid firmware doesn't let you shut off the IR illuminators.

One more reason to hate Reolink!

Doooooooood... I've been secretly wishing for this feature ever since I got my first camera. MAN, that would be an awesome feature! I guess the cable could be a weak point in the system, but I imagine some good engineering could overcome that weakness. Especially if the cable and external lights were replaceable. BTW, I'd like the camera to have two external lights, so that you could mount one a foot or two above and to each side. Powered and controlled by the camera. Awe... SOME!

Darn, I guess that means I can't patent the idea! Great minds....

Yep. Two separate ones would be great! An excellent option!

If you could have a really good waterproof connector setup on the main camera body, you could offer several types, too. Wide angle ones for wide angle cameras or zoom settings, and more spot-like ones for longer focal length settings. As it is, all of the cameras I have with built-in IR illuminators light up a bright "spot" in the center of the image when the camera is zoomed out wide. Even the Dahuas are like this. Being able to plug in a pair of wide-angle illuminators would make for a much better image!

 

[J Sigmo]

That's easy to do. I routinely shut off the IR in my cameras and use external IR illuminators. All it takes is a PoE splitter or a second cable run of CAT. In one instance I have an IR illuminator about 30 feet in front of the camera that give excellent depth lighting at night in a particularly dark area, and it's only a 7 watt illuminator. The evenness of lighting plus no bug/rain/snow problems makes it well worth the added effort.

I agree. Getting the light where it should be, and getting even illumination is a basic requirement for any photography. And this is, after all, photography! I like the idea of a light mounted "down-range" to even things out more. More hassle to run the extra wiring, but a much better effect, for sure!

 

[awsum140]

Don't forget to get some "Y" cables with the right size barrel connectors to split the 12 volt power to the camera and the IR illuminator.

I know what you mean, those round tuits are hard to find sometimes.

 

[dragoneggs]

Absolutely love the idea of moving the IRs away from the camera or having multiple IRs. That would be cool especially in a multi camera set up.

 

[dragoneggs]

This thread is drifting but I want to say thanks to the community here. A learning process for me. I did just set my recordings to direct to disk and halved my CPU usage. Again thanks to Wiki and all that contributed. Going to read some more Wiki now!

Went back and checked my CPU and yep... down from 23% to 11% for 6 cams running 2500x at 15fps. wahooo!

 

[dragoneggs]

Okay, OP here... I'm a slow learner but I am learning (by fire) that the Reolink's, at least the ones I have... suck! I have a few Dahua Starlights installed now and at least I don't have the cut outs, blurred half screen, etc. Fenderman warned me. That said, I am still not getting a big improvement on low light/night motion blur, and clear stills during the day with my Dahuas. Doing 15fps and 15 iframes. Think I might need to set up daytime and nighttime profiles and work with shutter speed. Lots to learn.

 

[dragoneggs]

You might not need to set up different profiles if your day vs night conditions aren't wildly different. What you can do is specify the slowest allowable shutter speed. There are a couple different ways to do it, here's how I specify 1/60th of a second (16.67 millisec) using "Customized Range." When there's more light such as in the daytime, the camera will use faster shutter speeds and lower gains. But at night when it's completely dark 1/60th will be the slowest speed and 60 will be the max gain. If you still get blur at 1/60th, you could try gradually shortening the speed. E.g. 10 msec corresponds to 1/100th, etc.

View attachment 37680

Thank you! Will play with this.

 

[dragoneggs]

Okay played with this... Dahua HDW5231EP-5SE, 15fps, 15iframe. Before was default settings. After was changing to 16.67ms per Dank suggestion. Improvement... yes. Good still capture... no. Can I do better?

 

[J Sigmo]

Keep in mind that 16.67ms is still only 1/60th of a second. If you're used to normal photography, you'll realize that 1/60th is often fine for still subjects, as long as your hand is steady. But it is not a shutter speed that will freeze subject motion.

Something more like 1/250th (4 milliseconds) would do a better job freezing the motion in your shots.

But a fast shutter speed like that will, of course limit the light that can reach the sensor, and that means using higher gain and the resulting higher noise.

Photography is always a series of tradeoffs.

If you want to freeze fast movement, you will simply need to have more light given the current state of the art in security cameras.

 

[dragoneggs]

Thanks J. I have some porch lighting and a motion sensor light that will help. I will try again tonight with faster shutter and compare. So is 'gain' equivalent to the old film speed rating ASA or ISO?

 

[dragoneggs]

Okay... here is my finding. Tested 1/100th, 1/250th, and 1/500th. The first two with gain set at default 0-50, for the 1/500th I turned it up to 70. Looks like 1/250th might be the sweet spot. Any other suggestions?

Note these are snapshots taken from the motion triggered video w/direct to disk record. Just noticed my timestamp is missing. Thinks I have to go turn that on in the Dahua camera settings.