Mobius Maxi 4K - Varifocal Zoom 3.6-11mm

[TonyM]

Following on from the popular threads Mobius Varifocal Zoom IR and Mobius 5MP Varifocal Zoom 6-22mm ƒ/1.6 both started by @Dashmellow, I was keen to try the new Mobius Maxi 4K paired with this 3.6-11mm 4K Varifocal lens offered by Fulekan via AliExpress.


8Megapixel M12 Mount Varifocal 4K Lens For IMX179/317/377/477 Action/Sports Cameras 1/1.8 inch 3.6-11mm Manual Focus and Zoom

Disclaimer : I received the Maxi 4K from Mobius for development and testing. I bought the lens myself from AliExpress.

I have used a pre-release version of the Maxi 4K, in the old-style case.
Note that the release version of the Maxi 4K has a built-in lens surround with an internal diameter that is just too narrow to fit the rear section of the Varifocal lens.

 

[TonyM]

The 3.6-11mm zoom range is rather versatile when using the Maxi 4K as a telephoto dashcam. This series of full-frame screenshots show the effect of using this lens at approximately the middle of its zoom range, compared to the standard Maxi 4K with its wide-angle 4K lens.

The telephoto video works well for capturing the number plates of cars that you are following, or observing the behaviour of drivers and other road users ahead of you such as using a mobile phone while driving. The metering is much less affected by dark or bright areas because the narrow FOV is concentrated on the road and cars ahead.

 

[TonyM]

Here are a few day & night compilation videos showing the Maxi 4K with the 3.6-11mm varifocal recoding alongside another Maxi 4K with the standard wide-angle lens.

Both cameras: 4K 30fps, 60Mbps, centre-weighted metering, EV+0

videos deleted

 

[Dashmellow]

These look great, especially the nighttime views compared to the Mobius 1. Let's hope we see a super-capacitor available for the Maxi 4K before too long.

Can you elaborate further on your comment about the internal diameter of the lens surround?

Note that the release version of the Maxi 4K has a built-in lens surround with an internal diameter that is just too narrow to fit the rear section of the Varifocal lens.

Are you saying the surround is "too narrow" for the threaded rear lens barrel to seat properly or some other part of the lens?

 

[TonyM]

Can you elaborate further on your comment about the internal diameter of the lens surround?

The ID of the lens surround is 18.45mm, which is a snug fit for the 17.9mm OD of the standard lens.


The OD of the zoom barrel is 19.0mm.

 

[Dashmellow]

Thanks for the more detailed explanation. Now I see what you were talking about.

It appears that you modified the housing to get the lens to fit.

This makes me wonder if the pcb and lens module from the Maxi 4K will fit into the housing from the original Maxi? That appears to be what you have in your "pre-release version" photo above.

 

[TonyM]

These look great, especially the nighttime views compared to the Mobius 1.

I was pleasantly surprised by the clarity of the night-time video. The camera's wide dynamic range and tendency towards highlight priority appear to work well on reflective number plates, without darkening the rest of the scene too much.

 

[TonyM]

Thanks for the more detailed explanation. Now I see what you were talking about.

It appears that you modified the housing to get the lens to fit.

This makes me wonder if the pcb and lens module from the Maxi 4K will fit into the housing from the original Maxi? That appears to be what you have in your "pre-release version" photo above.

The new pcb and lens module do fit, almost. You need to enlarge the opening for the mini-USB socket to accommodate the new USB-C socket. Then check the tab positions for the lens module.

My test camera is a hybrid to accommodate this lens.
The top half is a pre-release Maxi 4K. Old heatsink design. No lens surround. USB-C socket.
The lower half is an original Maxi, with the tab positions for a 'Maxi Lens B' lens module.
As before, the lens is screwed in so that the back flange is against the front of the case, rather than fixing the lens position with a set screw.

I hope the final release of the Maxi 4K capacitor version will come with the deeper, set screw type lens holder we get with the Maxi Lens B. Ideally without the lens surround too. Then we would not have to make any modifications to install a replacement lens.

 

[Dashmellow]

Again, thanks for the info.

It sounds like a bit of modification with a Dremel tool would be all that is required to get the Maxi 4K innards to fit the old Maxi case. Then again, one could simply cut the lens shroud off of the 4K housing using a Dremel tool fitted with a fine toothed circular saw blade and then clean up any rough edges that may remain. These blades look like this but with finer teeth.

 

[SawMaster]

It is utterly amazing at what details this captures at night I looked several times at several scenes and found things which the normal lens didn't even 'see', and many more where the difference was between an ill-defined shadow and a clearly identifiable object. The daytime performance is also quite nice.

Supercaps, we need supercaps. Modding the case can be done many ways by almost anyone but adding supercaps isn't exactly user-friendly and needs to be done for us.

Thanks for all the efforts @TonyM

Phil

 

[TonyM]

Supercaps, we need supercaps. Modding the case can be done many ways by almost anyone but adding supercaps isn't exactly user-friendly and needs to be done for us.

I am reliably informed that supercaps are on the way

 

[Dashmellow]

I've been wondering if the super-caps from the Maxi might fit? And if so, would they work?

What battery is in the 4K Maxi and what is its capacity?

 

[Dashmellow]

The IQ is impressive in the 4K. Curious about motion blur though, which we have not seen good examples of as yet, but If the camera is stable and reliable, Mobius may finally have something to write home about!

@TonyM, how about some footage of approaching traffic under various conditions?

 

[TonyM]

I've been wondering if the super-caps from the Maxi might fit? And if so, would they work?

What battery is in the 4K Maxi and what is its capacity?

The battery is identical to the original Maxi (950mAh), and I understand that the capacitors may also work but I have not verified this yet.

 

[TonyM]

how about some footage of approaching traffic under various conditions?

Specifically with the 3.6-11mm? Or with the standard lens?

 

[Dashmellow]

Specifically with the 3.6-11mm? Or with the standard lens?

Good question. How about a bit of both? Time permitting, how about posting something from the standard lens in the other thread and perhaps an example or two from the varifocal here in this thread?

Basically, the question arose for me when I saw that your video examples from both lenses, impressive as they appear were primarily of vehicles traveling in the same direction and so it seems that motion blur performance capturing oncoming cars would be an important criterion to demonstrate.

 

[Dashmellow]

The battery is identical to the original Maxi (950mAh), and I understand that the capacitors may also work but I have not verified this yet.

Thanks. That's good news! I'm already considering purchasing a Maxi 4K but I am reluctant to order one until there was a more definitive path to a super-cap and I just happen to have a super-cap from old my dead Maxi 1. If the battery works, the super-cap should, no? The issue appears to be that the firmware does not (as yet?) include a "power off disconnect" option.

 

[TonyM]

The issue appears to be that the firmware does not (as yet?) include a "power off disconnect" option.

If auto start on external power is selected, shutdown is effectively 'immediate' when external power is removed. There is no delay option.

I asked Mobius about the capacitor option. This was their response :

We test the super capacitor for original Mobius Maxi on 4K camera, it's working fine. But one concern is we may lose date/time if the camera is not used (ie capacitor not charged) for a few days.

 

[Dashmellow]

Thanks for the reply @TonyM.

As I remarked in the other Maxi 4K thread where you addressed the question: I'm pleased to hear that the existing super-cap will function, but of course it is disappointing that it won't power the camera for very long. This makes me wonder if there is room inside the housing for a larger, higher capacity super-cap module. Hopefully there will be a solution.

 

[TonyM]

The wide and telephoto extents of this lens cover a useful range for dashcam video.

At the wide end, the FOV is not much narrower than a typical dashcam.



At the telephoto end, the FOV is approximately 1/2 width and 1/2 height of the wide view.



My preferred view is close to the telephoto end, but pulled back far enough to include the front edge of the car, providing useful context or a reference point to the video.



These screenshots were taken from the iSmart DV2 app, connected to the Maxi 4K over WiFi.