Mobius Zoom Lens

[joe384]

Hi,

A while ago I sold one of my mobius cams (totally regret it now I know how useful they are)
However I still have one which I'd like to turn into zoom dashcam to work alongside my main front dashcam

I know there are a couple of threads on here that I have started to dig into, but what is generally considered the best option for the mobius at the moment? I see Treeye still sell the 5mp varifocal lens that Dashmellow and TonyM tried.

I will try and read through some of the threads here but there's quite a lot to read through!

 

[Dashmellow]

Hi,

A while ago I sold one of my mobius cams (totally regret it now I know how useful they are)
However I still have one which I'd like to turn into zoom dashcam to work alongside my main front dashcam

I know there are a couple of threads on here that I have started to dig into, but what is generally considered the best option for the mobius at the moment? I see Treeye still sell the 5mp varifocal lens that Dashmellow and TonyM tried.

I will try and read through some of the threads here but there's quite a lot to read through!

In my opinion, the 5MP varifocal zoom lens fitted to a Mobius camera is the hands down winner. What started out for me as an interesting experiment with the 3MP ƒ1.4 - 2.8mm to 12mm varifocal zoom IR in September of 2017 and later the 5MP Varifocal Zoom 6-22mm ƒ/1.6 became a "must have" addition to my dash cam arsenal. These lenses capture things is detail that a traditional dash camera would never even see! Often, it is the telephoto cam that really tells the story and provides the definitive evidence. I wouldn't be without a telephoto lens camera at this point.

Another more discreet and compact option would be a fixed focal length telephoto lens of either 8mm or 12mm. So, as if the varifocal threads were not enough to wade through already Joe, I highly recommend perusing the Mobius Telephoto Dashcam thread as well. Both @TonyM and @Harsh offer some great examples and there is much good discussion. I found Harsh's many videos and screen shots to be especially enlightening due to the comparisons between focal lengths and the day/night comparisons.

I'm actually considering adding a rear Mobius telephoto to my truck and the varifocals would not work there because of mounting limitations so it is a good time to revisit this topic.

 

[TonyM]

I am still using a Mobius with a fixed 6mm lens in my rear window where it is quite discreet.

My other two M1 cameras are now on long-term loan to my partner for her hobby, with my 2.8-12mm and 6-22mm lenses attached.

I have one more 6-22mm lens which I now use on a GitUp F1 in the same way it was used on a Mobius. Similar to @Dashmellow my personal favourite is the 6-22mm lens for its additional reach, and the image quality does appear to be better IMO. Compared to a fixed telephoto I do like the ability to adjust both zoom and focus without opening up the camera, making fine-tuning a much simpler task.

The larger barrel of the varifocal lenses also offers greater flexibility for attaching a CPL filter which can be a useful addition to a telephoto dashcam.

 

[SawMaster]

As luck would have it, my moving of house revealed my long-lost varifocal lens but not the RCA output cable I need for focusing Since I had a G1W-HC with a LCD screen on hand to play with I fitted it there, hoping that since they both use the AR0330 sensor it might work. Which it does after a fashion, bit only fully zoomed out which makes the fitting pointless. It seems to need the lens mount to be shorter- I haven't opened the Mobius to compare. Not sure of what I'll do next but at least I'm now back in the game somewhat so I'll take that for a win A second 'win' was that I discovered the reliability problem I'd been having with that G1W-HC was a loose USB socket which I've fixed so now I've got another cam with no place for it. A second loss is that I have no clue where my N2 Pro went, but it will turn up somewhere I'm sure.

Phil

 

[jokiin]

As luck would have it, my moving of house revealed my long-lost varifocal lens but not the RCA output cable I need for focusing

Phil

maybe use the webcam mode instead, only need the USB cable for that

 

[SawMaster]

Forgot about that- Thanks Jokiin

Phil

 

[joe384]

Ordered the varifocal lens from treeye, bargain at just under £10, got a months wait or so before it arrives though.

 

[Dashmellow]

Ordered the varifocal lens from treeye, bargain at just under £10, got a months wait or so before it arrives though.

I don't know about now but every order I've ever placed with Treeye arrived at my door in northeastern USA sooner than they said it would. I think they give themselves a bit of wiggle room as delays can often be expected and they'd rather have customers be pleasantly surprised especially now with all the online ordering due to COVID overwhelming carriers. Then again some items I've ordered from China really have taken a month or more to show up even before COVID, but so far never from Treeye.

 

[joe384]

It arrived today, just over a week Now time to read through the threads and learn how to set it all up

Ok, I must admit this lens stuff is a bit above me, the lens is retracted into the body about 5mm at the moment, how does it come out and what does each screw do?

Nevermind, just figured it out!

 

[Dashmellow]

It arrived today, just over a week Now time to read through the threads and learn how to set it all up

Ok, I must admit this lens stuff is a bit above me, the lens is retracted into the body about 5mm at the moment, how does it come out and what does each screw do?

Glad my prediction that it might show up sooner than later proved accurate!

Happy to try and answer any questions you may have and no doubt others will be happy to do the same. Might be an idea to post questions in the thread dedicated to this lens which might prove useful to the next person looking to purchase one of these since everything including your questions would be in one place. I wouldn't be too surprised if many of the questions you may have are already answered there anyway.

In any event, those two silver stalks on the lens unscrew. Loosening them allows you to adjust the zoom factor and the focus. Be sure to tighten securely once you are happy with your adjustments.

Edit: I see you edited your post to say you figured it out.

 

[joe384]

I am having an issue removing the mobius lens (C2) from the assembly. I have loosened the screw (I even took it out completely at one point) but the lens won't unscrew. I saw one video the guy mentioned about warming up with a hair dryer, not sure if I should try that though.

Do I need to remove the sensor board from the housing?

 

[Dashmellow]

I am having an issue removing the mobius lens (C2) from the assembly. I have loosened the screw (I even took it out completely at one point) but the lens won't unscrew. I saw one video the guy mentioned about warming up with a hair dryer, not sure if I should try that though.

Do I need to remove the sensor board from the housing?

This is an old issue. It came about when Mobius switched from a metal lens holder to a FRP (fiber reinforced plastic) lens holder which can cause a lot of friction with the threads of the lens once it gets screwed in and focused at the factory.
You don't want to remove the sensor board but you will need to remove the entire lens module from the camera so you can work with it in your hand and avoid damaging the sensor ribbon cable.

Gently heating the module with a hair dryer might help, just don't overdo it. Then again, the whole lens module gets fairly hot when operating so it can indeed handle some heat.

When I experienced this same problem the solution that finally worked for me was a pair of pliers that I modified with rubber padding to protect the lens. The padding I used was the rubber insert from a bicycle handlebar camera mount.

See THIS post and THIS thread for more info and some instructions.

 

[joe384]

Thanks, I just managed to do it. I heated it with a hairdryer (not too much though), put the lens cap on to protect the lens and then tried with some pliers.

One issue is I couldn't get my hex screw back in well due to slightly shaky hands and how small it is, I did get it in but it was stripping some threads slightly. However the lens is very tightly secured now so if I don't mess with it now I think it should be ok?

Next question is do I leave the copper style retaining ring on the lens? Also I am struggling to get the lens unit seated in the case, will I need to strip some of the end of the case with a knife?

 

[Dashmellow]

Next question is do I leave the copper style retaining ring on the lens? Also I am struggling to get the lens unit seated in the case, will I need to strip some of the end of the case with a knife?

If you mean the brass retaining ring at the back of the varifocal zoom lens, don't remove it; it holds the rear lens elements and focusing ring together. As for mounting the varifocal zoom lens I just screw it into the existing thread mount until it is tight against the camera housing and that is all that is required.

You can see how it should look here:

 

[Dashmellow]

One issue is I couldn't get my hex screw back in well due to slightly shaky hands and how small it is, I did get it in but it was stripping some threads slightly. However the lens is very tightly secured now so if I don't mess with it now I think it should be ok?

BTW, the grub screw tends to strip out easily on these FRP lens modules. A good fix-it to properly secure the lens in place is to apply a small dab of UV curing cement to the lens threads where it meets the lens barrel. It will hold strongly in place but can be easily undone with a gentle twist if you ever need to remove the lens in the future.

You can purchase UV curing cement for a modest price on Amazon. It usually comes with a small UV flashlight for curing. Great stuff! I always keep some around.

https://www.amazon.co.uk/gp/B08K863MSM

 

[joe384]

I am finding I can't get the sensor housing to sit in the "slot" in the case. It seems like I'd have to either unscrew the lens so the wide lens section sits further out, or take a knife to some of the plastic case around the lens housing.

 

[Dashmellow]

View attachment 54972

I am finding I can't get the sensor housing to sit in the "slot" in the case. It seems like I'd have to either unscrew the lens so the wide lens section sits further out, or take a knife to some of the plastic case around the lens housing.

It is hard to really see what you are trying to demonstrate in your photo.

As I said in a previous post here, "screw it into the existing thread mount until it is tight against the camera housing and that is all that is required"

What you want to do here is to re-install the lens module in its slot without any lens installed in it. Then screw the camera housing back together. THEN screw the new varifocal lens into the camera from outside the camera housing until fits tightly against the bezel.

Here is one of @TonyM's photos from the first page of the Mobius 5MP Varifocal Zoom 6-22mm ƒ/1.6 thread that much like the photo I posted above shows what it should look like when you've got it all together. Screwing the lens in tightly against the housing is all you need to do. You don't need any grub screw or glue for this although if you really wanted to you could apply a small dab of UV cement between the brass lens retaining ring and the camera housing once you've screwed the lens in.

 

[joe384]

Excellent, thanks for all your help

What I did was I screwed the varifocal lens into the sensor housing straight after taking the old lens out as I was just thinking about trying to prevent dust.

I am waiting on a new mobius case to be delivered (current one is a bit tatty) so when it arrives I will unscrew the lens and put the new case back first before screwing the lens on

 

[SawMaster]

I just got mine assembled and I had to start threading the lens with the case apart holdng the lens holder, mine wanted to cross-thread otherwise. Next to get it focused once I dig through the cables and find one that works

Phil

 

[Dashmellow]

Excellent, thanks for all your help

What I did was I screwed the varifocal lens into the sensor housing straight after taking the old lens out as I was just thinking about trying to prevent dust.

I am waiting on a new mobius case to be delivered (current one is a bit tatty) so when it arrives I will unscrew the lens and put the new case back first before screwing the lens on

I don't know how old your original Mobius camera is but keep in mind that there was change to the housing at some point along the way such that certain vintage lens modules no longer fit the new slot. It's been so long I don't remember the exact point where the charge took place. In any event, if the new case slot doesn't fit your current lens module, now you'll know why.

Anyway, I realize I should have explained something that might have helped you better understand how to mount the new lens but better late than never as they say. You may find the explanation useful anyway.

Traditional M12 lens that are used in dash cams and actions cams are simple threaded barrels that screw into the module housing and are adjusted for focus by screwing them in or out until you achieve the proper focus.

Traditional camera lenses like on a DSLR or other standard still or cinema cameras have a fixed lens mount. Some are bayonet mounts and some are threaded. All these lenses attach to the mount in a very precise manor so that they achieve the proper distance to the film surface or senor plate and so that they are secure and stable. They can do this because they are designed with a "flange". The precise distance from the rear element of the lens to the sensor is called the "flange focal distance".

These varifocal zoom lenses are designed for traditional larger CCTV cameras and so they have the flange. As such they were never really designed to attach to a tiny M12 lens pocket camera like the Mobius but they can.

By using the variable focus capability you can adjust the position of the rear element to compensate for what would otherwise be a fixed distance on a traditional camera, although you might lose (or gain) some of the focal range of the lens. Thus you just screw it into the housing as far as it will go instead of having to screw it in and out to achieve focus. For this reason you want the case closed when you attach the varifocal lens to a Mobius.

No flange






Technically the mount on the camera is the actual "flange" and the flange focal distance (FFD) is measured from there but the lens itself also has one that matches this same surface. Since the Mobius camera doesn't have an actual flange, for our purposes the back of the lens itself as shown above is considered the flange.