BlackVue X Plus Series Rear Camera - Dark Rear Video

[rcg530]

The rain has disappeared yet again during what should be our rainy season here in northern California. I wanted to see if the replacement DR750X-3CH Plus rear camera would still produce underexposed video on a sunny day as well the the cloudy days. It does.

Here is one DR750X-3CH Plus front/rear camera video showing the rear is once again underexposed. The overall video brightness is darker in the rear video. You can see color differences in the building in the middle of the field of view as well.


The DR750X-2CH Plus rear video is darker than its front camera, but it appears to be a bit brighter than the DR750X-3CH Plus rear camera video.


I also want to point out there are select times when the exposure level of the rear camera is much better, but still not the same as the front camera. Pittasoft marketing and support has agreed with the idea that the front camera video should be just a tiny bit darker than the rear video (reverse of what's happening) because the front camera is recording at 60 fps while the rear camera is recording at 30 fps.

I first noticed the darker rear camera video with a DR900X-2CH Plus dashcam a couple of months after my review of that dashcam. There were more clouds in the sky in late fall which made it more likely to have the lighting conditions the best provoke the underexposure issue. The reason Pittasoft wanted me to switch to the DR750X Plus dashcams to test this issue was that both the front and rear cameras have the same image sensor and thus should generate similar brightness video in the same lighting conditions (noting the FPS difference I just mentioned).

In this front/rear screenshot, you can see the rear video is brighter than in the previous examples, but it is still about 15 percent darker than the front camera video.



I really would like a resolution to this issue soon from Pittasoft. It has consumed multiple weeks of my time gathering video, analyzing it and making reports to Pittasoft about this problem.

 

[rcg530]

I went on my weekly shopping trip today. The DR750X-3CH Plus rear camera continues to produce the underexposed (dark) rear video. I have both the front and rear cameras on the front windshield for a side-by-side comparison.

I used Dashcam Viewer Plus v3.8.3 to walk through the day's footage more easily.

Left = DR750X-3CH Plus Front / 1080p @ 60 fps
Right = DR750X-3CH Plus Rear / 1080p @ 30 fps

I'll include the thumbnails in this post. Click on each one to expand them to their full size. Even from the thumbnail view of each picture you can see the right side (rear camera) is darker than the left side (front camera).

 

[StrayCam]

I just had a thought... have you tried different firmware to see if they produce the same results? I realize this problem exists in several of Blackvue's models, and it may be hard to isolate different firmware.

I just realized today thanks to @Eskater that I have FW 1.000 still on my 750x 2Ch LTE Plus. I will update you 1.002 to see if I get the same results.

 

[rcg530]

I just had a thought... have you tried different firmware to see if they produce the same results? I realize this problem exists in several of Blackvue's models, and it may be hard to isolate different firmware.

I have tried multiple firmware versions with each of the three models of dashcams that have had this problem - that I've had in my possession.

DR900X-2CH Plus - 1.000, 1.001 & 1.002 (non-public releases - not tested), 1.003, 1.004 and the most recent 1.005.

DR750X-2CH Plus - 1.003 (arrived with this version if I recall correctly), 1.004 & 1.005 (non-public releases - not tested), 1.006 and the most recent 1.007

DR750X-3CH Plus - 1.000 (first unit arrived with this version), 1.001 (second unit arrived with this version) and the most recent version 1.002. I didn't try 1.000 with second unit - I didn't download the firmware zip file from BlackVue site when the dashcam was first released.

Every firmware that I've tested with these three models of dashcams have produced the underexposed rear video.

Pittasoft support has had me reinstall the firmware files via the manual method each time I question anything about the dashcams. It's almost like they don't fully trust the app or cloud installation method of their firmware.

 

[StrayCam]

I have tried multiple firmware versions with each of the three models of dashcams that have had this problem - that I've had in my possession.

DR900X-2CH Plus - 1.000, 1.001 & 1.002 (non-public releases - not tested), 1.003, 1.004 and the most recent 1.005.

DR750X-2CH Plus - 1.003 (arrived with this version if I recall correctly), 1.004 & 1.005 (non-public releases - not tested), 1.006 and the most recent 1.007

DR750X-3CH Plus - 1.000 (first unit arrived with this version), 1.001 (second unit arrived with this version) and the most recent version 1.002. I didn't try 1.000 with second unit - I didn't download the firmware zip file from BlackVue site when the dashcam was first released.

Every firmware that I've tested with these three models of dashcams have produced the underexposed rear video.

Pittasoft support has had me reinstall the firmware files via the manual method each time I question anything about the dashcams. It's almost like they don't fully trust the app or cloud installation method of their firmware.

It's clear you have been very meticulous in doing all your testing!

Is there any reason Pittasoft/Blackvue hasn't introduced a setting in a new firmware that would allow one to simply adjust the exposure of the rear video like they used to have in prior Blackvue dashcam models? Or is this impossible to do?

 

[rcg530]

Is there any reason Pittasoft/Blackvue hasn't introduced a setting in a new firmware that would allow one to simply adjust the exposure of the rear video like they used to have in prior Blackvue dashcam models? Or is this impossible to do?

The story is they took the EV / HDR settings out because it was difficult for their developers to allow the end user to modify the EV values / HDR setting and for them to account for those changes in the various places in the firmware where it would need to be accounted for or compensated for in the firmware logic and still yield a good image quality.

IMO, their developers didn't get the EV logic right for the image sensor in the RC110F rear camera. The same image sensor is used in the DR750X Plus front camera and that looks good.

 

[Eskat8r]

The below are screen shots of video I wanted to upload, but couldn't. Clarity is obvious between the front and back. But, in my car I have tint on the back window. I think its pretty good for a rear camera having to burn thru tint. At that time, I was on Firmware 1.002.

I have noticed on 1.002 that disconnects are more frequent than 1.000 and 1.001. But, that also could've been a faulty dashcam. I have a new cam and upgraded to 1.002 last night manually. I put notifications on, so will see what happens during my day at work. I'll post results.

I was wondering why they took away the options for the rear camera in the 750 LTE plus. But, you answered that above.

 

[StrayCam]

The below are screen shots of video I wanted to upload, but couldn't. Clarity is obvious between the front and back. But, in my car I have tint on the back window. I think its pretty good for a rear camera having to burn thru tint. At that time, I was on Firmware 1.002.

I have noticed on 1.002 that disconnects are more frequent than 1.000 and 1.001. But, that also could've been a faulty dashcam. I have a new cam and upgraded to 1.002 last night manually. I put notifications on, so will see what happens during my day at work. I'll post results.

I was wondering why they took away the options for the rear camera in the 750 LTE plus. But, you answered that above.

If you upload your videos to Google Drive, One Drive, etc... you can then right click the file(s) in the cloud service and click on share with link (choose option to let anyone with link open file). - - That will enable you to get files uploaded here in DashCamTalk.

How dark is your rear tint? Because the rear cam is running twice as slow as the front camera (30 fps vs 60 fps), video should be brighter on the rear cam. Your tint may just even things out... same brightness for both.

 

[Eskat8r]

Let me know if these work. Sorry, I don't remember how dark, but pretty low. Maybe 20%

https://drive.google.com/file/d/1LSWfhuEcRJ_WJGhfEL91A5rIR4NcKPc6/view?usp=drivesdk

https://drive.google.com/file/d/1LYyHs4dxnhPv3g9_B7gpNWiOtr6LkCEa/view?usp=drivesdk

 

[StrayCam]

I can't view those files on my phone... probably because Google Drive isn't on my phone...?

If you click on the add link button when creating/editing your post, it will let you name your file as well as share your link. - You might give that a try.

 

[Eskat8r]

I can't view those files on my phone... probably because Google Drive isn't on my phone...?

If you click on the add link button when creating/editing your post, it will let you name your file as well as share your link. - You might give that a try.

So this will change the name, will it help you see the content!! Or you'll have to use something with google drive

 

[StrayCam]

So this will change the name, will it help you see the content!! Or you'll have to use something with google drive

Your file name in Google Drive won't change at all. You can for example name a video: Front Video and another Rear Video. That's just for DashcamTalk.

And as long as when you get the shared link from Google Drive, you select anyone with link can open, then all users here in DashcamTalk will be able to play your videos, whether they use Google Drive or not. - Hope this helps.

 

[Eskat8r]

Good to know. Main reason I wanted to upload the video is to better see the video quality of the rear camera. I think screen shot might not show as well. When you finally view it, go thru the whole video... You'll see something cool.

 

[rcg530]

Hello @Eskater / @StrayCam

I'd like to keep the posts in this thread focused on the underexposed (dark) rear camera video topic. I would encourage you to continue your discussion about the DR750X-2CH LTE Plus dashcam specific issues in another thread. Thanks for understanding!

 

[Eskat8r]

No problem

 

[Eskat8r]

Did the link work for the videos?

 

[StrayCam]

Hello @Eskater / @StrayCam

I'd like to keep the posts in this thread focused on the underexposed (dark) rear camera video topic. I would encourage you to continue your discussion about the DR750X-2CH LTE Plus dashcam specific issues in another thread. Thanks for understanding!

Totally understand rcg530! We went way off-track with @Eskater's issue.

I plan on doing more testing today on my rear dashcam. I don't believe overcast conditions are in today's Nor Cal forecast, so the darker rear video may not show up as much.

 

[rcg530]

I plan on doing more testing today on my rear dashcam. I don't believe overcast conditions are in today's Nor Cal forecast, so the darker rear video may not show up as much.

Actually, overcast skies can produce some of the more dramatic examples of this issue. The front camera will allow the sky/clouds to be overexposed (which is okay by me) while the ground level is exposed decently. The rear camera will adjust its exposure level so the bottom side of the clouds are exposed well enough to see details of the clouds, but the ground level exposure is too dark.



More examples in this post https://dashcamtalk.com/forum/threa...rear-camera-dark-rear-video.46470/post-571776

 

[rcg530]

Another week of driving with the replacement DR750X-3CH Plus dash cam has been completed. While I will agree that there are select moments with clear and sunny skies the front and rear video brightness level differences are not as noticeable, the rear camera video is still just a bit darker. It's when there is less direct light or overcast skies the biggest front/rear brightness level differences can be be observed.

The important thing to keep in mind is that the DR750X Plus 2-channel and 3-channel dash cams with the RC110F rear camera have the same Sony STARVIS IMX327 image sensor in the front and rear cameras. The rear camera records 1080p @ 30 fps video and the front camera records 1080p @ 60 fps video. Due to the higher frames per second (fps) used with the front camera, the video brightness level should be slightly darker than the rear video, but it's not darker.

This example is with clear/sunny skies on 06-Apr-2022.


Here's an example with clear/sunny skies but the sun is behind the vehicle. You can start to see a more noticeable difference between the front and rear exposure levels.


Another overcast sky example showing how the firmware exposure level logic is not selecting the best/correct exposure level resulting in underexposed rear video.

 

[Eskat8r]

Very noticeable in the last pic. Do the firmwares play any part in exposure?