My review of the SDT8C842-8P-FA-APV-0280 2×1/1.8" CMOS 8MP 42x (versus the PTZ1A2M-25X 2MP 25×)

[Noober]

The new POE injector got the new camera up and running. It will take me a bit to figure out all the settings and such to generate something useful, but my plan is to share photos and video of these two cameras for comparison. If there is something anyone would like to me to share I'm all ears, although it might take me a bit to learn how to use the Dahua web interface to make it happen.

The comparison will be between the camera we have been using for over a year now:

EmpireTech PTZ1A2M-25X 2MP 25× Starlight IR 4.8mm–120mm Vari-Focal Pos

2MP, 1/2.8" CMOS 25x optical zoom Starlight technology IR distance up to 150 m Auto Tracking 3.0 Perimeter protection Face detection Video Metadata IP67

empiretech01.com

and the much more expensive camera we just got up and running:

EmpireTech SDT8C842-8P-FA-APV-0280 2×1/1.8" CMOS 8MP 42x Starlight Dua

Panorama: 2 × 4 MP 1/1.8" CMOS image sensor Detail: 8MP 1/1.8" CMOS image sensor 42 x optical zoom IR distance up to 300 m Auto tracking Perimeter protection Face detection Wiper IP67 Sound and light alarm PoE++(802.3bt)

empiretech01.com

For the test, the cameras are about 25 feet from each other. Here is the 25x camera taking a photo of the elevated 42x camera.





These photos aren't indicative of the full quality of the camera as I have them streaming and set to just a 1MP HD quality at the moment. But this shows both cameras at full zoom looking at the same distant snow spot that is the same distance away to each spot.

Here is the 25x zoom:



And here is the 42X zoom:



A different vantage of a distant cabin at full zoom (the cabin is about 25 feet or so closer to the 42x camera but I'm sure that's imperceptible). 25X camera:



And the 42x camera at full zoom:



That's all I got for now. I was expecting 42x optical zoom to be MUCH better than the 25x optical zoom than this so I'm pretty disappointed in this expensive camera at this point. The image is better, but I expected the zoom to get an image much further out than this.

Edit: the disappointment is due to my ignorance and lack of research. I had unrealistic expectations of the zoom. But the zoom actually does deliver, the quality of the camera footage is solid, and the panoramic view makes this camera a good purchase, I'm happy with it. But I can't afford any more of them

 

[tmxv4128]

I'm looking forward to reading your review. Comparison of the two cameras sounds interesting, and I appreciate how much work compiling everything entails.

 

[wittaj]

Looking forward to the review!

For some reason the site is acting up again with allowing photos to be added. Keep trying, it will happen.

 

[steve1225]

After trying to upload several times, it would appear that I don't have permission to upload images here for some reason.

uploads works now for last a few days...
there are 2 methods of upload images - one is "Attach files" button, second is drag&drop of image file into new post edit box..
you can try both...

you can also try to switch browsers...

 

[steve1225]

I just tried both of those methods on Safari and both using Firefox. Neither worked.

did you try both methods of uploading pictures?

 

[tmxv4128]

Wondering how the photos are formatted. JPEGs?

 

[steve1225]

different computer? different internet provider?
try from mobile with disabled WIFI (over LTE/5g)?

 

[Noober]

I was able to upload images this time. I've updated the OP to show a zoom comparison. I'll do some more comparisons on image quality and such in the future and share the pano footage from the 42x camera. So far the images shared are from the "detail" PTZ camera of the 42x camera.

 

[bigredfish]

The new POE injector got the new camera up and running. It will take me a bit to figure out all the settings and such to generate something useful, but my plan is to share photos and video of these two cameras for comparison. If there is something anyone would like to me to share I'm all ears, although it might take me a bit to learn how to use the Dahua web interface to make it happen.

The comparison will be between the camera we have been using for over a year now:

EmpireTech PTZ1A2M-25X 2MP 25× Starlight IR 4.8mm–120mm Vari-Focal Pos

2MP, 1/2.8" CMOS 25x optical zoom Starlight technology IR distance up to 150 m Auto Tracking 3.0 Perimeter protection Face detection Video Metadata IP67

empiretech01.com

and the much more expensive camera we just got up and running:

EmpireTech SDT8C842-8P-FA-APV-0280 2×1/1.8" CMOS 8MP 42x Starlight Dua

Panorama: 2 × 4 MP 1/1.8" CMOS image sensor Detail: 8MP 1/1.8" CMOS image sensor 42 x optical zoom IR distance up to 300 m Auto tracking Perimeter protection Face detection Wiper IP67 Sound and light alarm PoE++(802.3bt)

empiretech01.com

For the test, the cameras are about 25 feet from each other. Here is the 25x camera taking a photo of the elevated 42x camera.

View attachment 228556



These photos aren't indicative of the full quality of the camera as I have them streaming and set to just a 1MP HD quality at the moment. But this shows both cameras at full zoom looking at the same distant snow spot that is the same distance away to each spot.

Here is the 25x zoom:

View attachment 228557

And here is the 42X zoom:

View attachment 228555

A different vantage of a distant cabin at full zoom (the cabin is about 25 feet or so closer to the 42x camera but I'm sure that's imperceptible). 25X camera:

View attachment 228558

And the 42x camera at full zoom:

View attachment 228559

That's all I got for now. I was expecting 42x optical zoom to be MUCH better than the 25x optical zoom than this so I'm pretty disappointed in this expensive camera at this point. The image is better, but I expected the zoom to get an image much further out than this.

Zoom should be right at 2X for the 42X which it appears to be?
MM is what matters, Zoom "x" value is based on the original unzoomed lens

So 120mm zoom vs 231mm zoom in this case

 

[Noober]

Zoom should be right at 2X for the 42X which it appears to be?
MM is what matters, Zoom "x" value is based on the original unzoomed lens

So 120mm zoom vs 231mm zoom in this case

I'm sure I'm just ignorant, I never factored MM into zoom. I was under the impression that for the 25x camera, the image fully unzoomed, would be 25 times bigger/closer at full zoom. And that 42x would be about 60% more than that.

If optical zoom is 42x, shouldn't that mean that the fully unzoomed image from the camera, if it showed a nickel, should be able to see a nickel that is 42 times further away?

You say zoom "should be right at 2X for the 42X" and that statement seems problematic to me. I would think, and I'm sure I've fallen victim to advertising speak, that it should be right at 42X for the 42X.

 

[Noober]

Here is an image from the 42x camera's panoramic camera. It's not the full quality the camera is capable of, but gives an idea of what it does.



And here is the "detail camera" of the 42x full zoomed in on the glacier (that is mostly covered in cloud at the moment) in the distance. Impressive, but not much more impressive than what the 25X is capable of although the quality of the 25x camera image isn't as good.



0:35 in this video shows the glacier from the 25x camera for reference although it was taken at a different time.

 

[bigredfish]

It’s a 120 mm lens vs 231mm lens

Zoom is marketing speak and relative to the starting point

 

[Noober]

It’s a 120 mm lens vs 231mm lens

Zoom is marketing speak and relative to the starting point

I don't understand how that works. I would think the starting point would be the image shown when fully unzoomed.

 

[bigredfish]

Correct and they’re different

4.8 mm–120 mm (25x 4.8)
5.5 mm–231 mm (42x 5.5)

At great distances it’s much harder to perceive the difference in zoom.

Look at the size of trees in the immediate foreground of the cabin for example and compare them

Also that extremely low resolution is making it seem worse.
Adjust bitrate on both to at least 10240

 

[wittaj]

I don't understand how that works. I would think the starting point would be the image shown when fully unzoomed.

As bigredfish points out, the starting points are different.

Let's look at two hypothetical cameras, both with 42x zoom.

One starts at 1mm and the other starts at 6mm focal length.

The one at 1mm zooms to (1*42) 42mm.

The 2nd camera at 6mm zooms to (6*42) 252mm

So both are 42x zoom, but one maxes out at 42mm and the other at 252mm, which is a big difference.

So in the instance of your two cameras, one at 25x and the other at 42x, due to different starting points, the actual difference between the two cameras is the 42x is double the 25x at full zoom.

That is why we say zoom Xtimes is marketing.

Cameras like Reolink claim a higher Xtimes zoom by starting with a much smaller focal length.

 

[steve1225]

Correct and they’re different

4.8 mm–120 mm (25x 4.8)
5.5 mm–231 mm (42x 5.5)

At great distances it’s much harder to perceive the difference in zoom.

Focal lengths are bullshit data in CCTV cameras.. camera manufacturers cheat here all the time...

You should look at horizontal Field of View:

PTZ1A2M:


SDT8:


PTZ1A have horizontal FoV 58.5 to 2.8 degree horizontal - it's only 21x (58.5 / 2.8) zoom ratio.. not 25x

SDT8 have horizontal FoV 61.8 to 2.2 degree horizontal - it's only 28x (61.8 / 2.2) zoom ratio.. not 42x

Both cameras starts at very similar wide FoV around 60 +/- 2 degree horizontal.. but ends are different - 2.8 vs 2.2 as number don't look different but it's almost 30% (2.8 / 2.2) more zoom level

 

[steve1225]

The new POE injector got the new camera up and running. It will take me a bit to figure out all the settings and such to generate something useful, but my plan is to share photos and video of these two cameras for comparison. If there is something anyone would like to me to share I'm all ears, although it might take me a bit to learn how to use the Dahua web interface to make it happen.

The comparison will be between the camera we have been using for over a year now:

EmpireTech PTZ1A2M-25X 2MP 25× Starlight IR 4.8mm–120mm Vari-Focal Pos

2MP, 1/2.8" CMOS 25x optical zoom Starlight technology IR distance up to 150 m Auto Tracking 3.0 Perimeter protection Face detection Video Metadata IP67

empiretech01.com

and the much more expensive camera we just got up and running:

EmpireTech SDT8C842-8P-FA-APV-0280 2×1/1.8" CMOS 8MP 42x Starlight Dua

Panorama: 2 × 4 MP 1/1.8" CMOS image sensor Detail: 8MP 1/1.8" CMOS image sensor 42 x optical zoom IR distance up to 300 m Auto tracking Perimeter protection Face detection Wiper IP67 Sound and light alarm PoE++(802.3bt)

empiretech01.com

For the test, the cameras are about 25 feet from each other. Here is the 25x camera taking a photo of the elevated 42x camera.

View attachment 228556



These photos aren't indicative of the full quality of the camera as I have them streaming and set to just a 1MP HD quality at the moment. But this shows both cameras at full zoom looking at the same distant snow spot that is the same distance away to each spot.

Here is the 25x zoom:

View attachment 228557

And here is the 42X zoom:

View attachment 228555

A different vantage of a distant cabin at full zoom (the cabin is about 25 feet or so closer to the 42x camera but I'm sure that's imperceptible). 25X camera:

View attachment 228558

And the 42x camera at full zoom:

View attachment 228559

That's all I got for now. I was expecting 42x optical zoom to be MUCH better than the 25x optical zoom than this so I'm pretty disappointed in this expensive camera at this point. The image is better, but I expected the zoom to get an image much further out than this.

that's last picture is very soft / out-of-focus...

This is probably because the shot captures the top of a nearby tree (bottom left corner of the photo). Next time, try capturing a shot where no close-up objects are visible... and the image in the distance is sharp...

The color processing is also completely different...

 

[Noober]

that's last picture is very soft / out-of-focus...

This is probably because the shot captures the top of a nearby tree (bottom left corner of the photo). Next time, try capturing a shot where no close-up objects are visible... and the image in the distance is sharp...

The color processing is also completely different...

I'll put an SD card in the 25x camera here before long and then try to share the highest quality photos and video I can. I'm assuming saving to the SD cards on the cameras will get the best quality instead of capturing from a stream over the network. It saves in a .DAV format though, so I need to find a way to convert .DAV on a Mac.

 

[bigredfish]

And increase the bitrate to something reasonable

 

[Noober]

Full zoom with the 42x.