Model Train-related Notes (a.k.a. “blog”) -- these are personal notes and musings on the subject of model train control, automation, electronics, or whatever I find interesting.
2018-12-09 - SQ23 Mini Camera for Cab RidesCategory Video
After trying the SQ12 camera, I moved on to its newer sibling, the SQ23. The goal is to use it to record cab rides. As this one has wifi, a secondary goal is to see if it’s suitable as a “live camera” e.g. to broadcast a ride view to a screen.
Cab ride filmed using SQ23 Camera
From left to right: SQ12, SQ23, Mobius compared to an HO-size engine + gondola
From left to right: SQ12, SQ23, Mobius, top view.
Although the SQ23 is larger, at 30x28 mm it still fits neatly inside the HO-size gondola and fits within the HO gauge clearance (although you may want to double check the height if using the “old era” NRMA gauge for tunnels):
I’m going to do my review in reverse by starting with what was terrible, and then what worked well.
The negative points:
- Similar to the SQ12, this is not a 30 fps camera, it’s a 25 fps with a 2:3 pulldown!
- Although the image really records at 1080p this time (i.e. it does not seem upscaled like the SQ12), it’s still fairly soft and lacking sharpness. Either the lens isn’t great, or it is not in focus, and there’s no way to adjust it.
- Extremely poor automatic exposition & white balance handling from the camera. The video is mostly neutral most of the time and will wildly shift to over saturated under some type of lighting. There’s unfortunately no control over this.
- White balance was often off, with a clear green tint under fluorescent lighting and an extremely pronounced yellow tint under LED lighting, then it would suddenly fix itself to something neutral. Filming the same scene twice would not given consistent white-balance results. This is a headache from a video editing perspective.
- The video shows extreme “beat effect”, as typically seen with 60 Hz light flickering not matching the recording frame rate of 25 Hz.
- When initiating a video recording via wifi (see below), there’s a “beat effect” on the recording sound too.
I’ve added a cab ride video of the layout at the beginning of the article. It shows the fairly wild and inconsistent white-balance issue, and the flickering. One issue I found is that although the camera did the layout tour twice, it did not get the lighting the same way every time. This makes it harder to mix & match video clips in edit/post and is fairly obvious in the video.
Let’s move on with the review.
Specs for the SQ23 generated files in 1080p:
Input #0, avi, from 'MOVI0025.avi':
ISRC : Generplus
artist : Generplus
copyright : Generplus
date : 2010-06-29
Duration: 00:10:00.07, start: 0.000000, bitrate: 24533 kb/s
Stream #0:0: Video: mjpeg (MJPG / 0x47504A4D), yuvj420p(pc, bt470bg/unknown/unknown), 1920x1080, 24343 kb/s, 30 fps, 30 tbr, 30 tbn, 30 tbc
Stream #0:1: Audio: pcm_s16le ( / 0x0001), 32000 Hz, 1 channels, s16, 512 kb/s
Despite the size similarity, this camera and its sibling the SQ13 differ from the previous models in that it has wifi. This is something I desire, not necessarily for streaming, but for ease of setting up. My goal on these cab rides is to enable wifi while I setup the camera on the train or scenery to adjust the view, then I can turn it off and record without wifi during the cab ride to save on battery.
That goal is easily accomplished with this specific camera. When wifi mode is enabled, the wifi generates a local wifi network, which has a password by default. The documentation even encourages users to change it first hand, which is a nice touch. There’s a QR code in the skinny documentation that leads to an Android app, with terrible reviews. Sure it’s not the greatest app ever, but once one understands how to use it, it’s quite usable. Many of the negative reviews complain that some parts of the app are poorly translated and there are still Chinese strings on screen -- OMG, can you believe it, the whole world doesn’t speak solely English! That didn’t bother me as it always showed up in parts of the app that were logical and easy to understand due to other iconography.
Since the wifi process was similar to the RunCam2, I had no problem understanding what to do, but I can see how others might struggle with it, so let’s me give an example:
- Turn the SQ23 camera by pressing the power button 3 seconds. Red led turns on.
- Turn the wifi mode by pressing the M button 3 seconds. Green led turns on.
- Wait a few seconds and connect the phone to the “SQ13_something” wifi network that appears (yes I totally see the irony in the model number). Note that range should probably be in the 2-6 feet to work.
- The first time, wait for Android to realize this network has no internet access. Android will pop up a notification asking whether to stay connected → check the remember box and say yes at this point, otherwise Android will automatically disconnect from the network, making the whole process a big pain.
- Once the phone is connected to the camera’s wifi, the green led blinks. The app will not work if the green led is steady.
- Install and launch the app, or if already launched, click the big “play” text. App tries to connect. Sometimes this takes a few tries but overall it was fairly reliable when I tried.
- At that point you can use the settings button, e.g. to turn the timestamp off.
- Once the connection is established, the screen change to a page that has the video in the middle and 2 rows of similar vertical icons: the left ones are to record on the phone, and the right ones are the record on the camera sdcard. There’s an icon to take a picture, one to record a video, and a media manager access to see recorded files (play, download).
Anecdote: The Android app’s name is “Sports DV” and the internal package name is “com.libo.GPCamDemoa”. GP here obviously stands for General Plus, which makes the GPCV4247 chipset. “Cam Demo” is kind of cute in the package name.
Here’s a screenshot of the app once connected, same engine as seen in the pictures above:
Obvious issues here:
- Pronounced yellow tint under my 3000K LED lighting (which nowhere looks like that in real life, as can be seen with the pictures above of the same engine & location, taken with the cell phone).
- Lack of clarity, camera was about 4 inch away from the engine.
- Barrel distortion to be expected from the wide angle.
What you do not see is the “beat” effect even on the LED lighting. This is however visible in the first few seconds of the youtube clip above.
When recording sound, the volume is consistently 6~9 dB below was I got from the SQ12 -- I actually had to tone down the SQ12 volume by 6 dB when editing the cab ride video. That wasn’t much a problem here and the level was acceptable. The video posted above has the volume level unchanged.
Sound Issue when Recording from the App:
The right middle button on the app initiates a recording to the sdcard. One would think it would give the same results as when recording on the camera without using wifi. However that’s not the case. Although the video is of the same quality, the audio is different and contains a pronounced “flutter / beat effect”. Here is a video sample with the raw sound & video as recorded:
So far I’ve established that the camera can be used for cab rides, with the caveat that the beat effect on the video and the sound and an overall vastly unimpressive video quality make it basically unusable for that purpose.
Is it a good camera to provide an onboard live view on the layout? Well “somewhat maybe not really”:
- Using the wifi mode quality drains the battery, more than just straight recording. A quick estimate is that we’d be lucky to get half an hour out of it and I think I’m being extremely generous here. Probably a lot less actually.
- Since the device is the one generating the wifi hotspot, the range becomes an issue very quickly. A quick test worked fine with a 3-4 yard range in direct line of sight, with some noticeably choppiness in the video stream when I was getting farther. However since all the tunnels on this layout are wire mesh, I don’t think it will work very well for a full layout tour due to the combination of distance and obstacles to the signal.
The battery aspect could be solved with e.g. extra batteries and maybe trying to recharge them from the track’s power supply. The signal obstacle is not really easy to solve though.
All in all it’s not a bad little camera. I can easily be found for ~$20, which is quite a lot less than a Mobius or RunCam 2 (around $70-90). However on this camera, the video recorded was really not suitable for recording cab rides and is a step down. All these cameras struggle with the kind of uneven lighting used on layouts yet this one managed to fare even worse.
Like the RunCam 2, it’s a bit of a death by thousand cuts -- every feature is nice yet every feature also has just enough of an issue to ruin it. It can be used to record cab rides, but not good ones. It can record from the phone app, but that gives bad sound. It can be used to do live view, but not very long or with lots of drop outs. It can do 1080p, but it lacks sharpness.