Mobius Zoom Lens

[joe384]

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.

I actually found a few posts by you and tony where tony had to modify the case and also you mentioned you had swapped in a longer lens holder in your mobius. But like you say, I don't need to worry about any of that, just screw it on with case together.

I will check out the link for the uv bonding, that may come in handy at some point.

 

[Dashmellow]

I actually found a few posts by you and tony where tony had to modify the case and also you mentioned you had swapped in a longer lens holder in your mobius. But like you say, I don't need to worry about any of that, just screw it on with case together.

I will check out the link for the uv bonding, that may come in handy at some point.

This varifocal lens is designed for a full size standard CCTV camera but it will function just fine when fitted to a Mobius. On the other hand the original specifications for the lens such as near and far rated focal length, circle of coverage of the lens and BFL (back focal length) requirement will be different than on a standard camera.

In certain circumstances depending on the length of the sensor module lens barrel threads in the camera one might need to be able to get the back of the lens closer to the sensor to achieve the proper BFL thus requiring the need to trim the case. Another issue is that the varifocal lens is designed for a 1/2.5" image sensor but the Mobius has a 1/3" sensor which is smaller and so the apparent focal length will be different than the actual varifocal lens specs so the distance of the rear lens element to the sensor can alter the results.

I forget now which camera @TonyM modified and why he did that but I believe it was a Maxi. I'm sure Tony can explain his reasoning.

 

[TonyM]

There are two types of Mobius case which allow for the two types of lens module available. The D and C2 modules have a thin base, whereas the original A has a thicker base. The different cases have different spaced out tabs that hold the sensor module in place. It is quite easy to remove these with a craft knife so that the module is free to move front-to-back. As @Dashmellow says, the easiest and most secure way to install the varifocal lens is with the back flange tight against the front of the plastic Mobius case.

I had one case where I did these modifications, then tried going back to using a D lens for a while. The lens module was then slightly loose within the case since there were no tabs to hold it in place. At least replacement cases are cheap, and thankfully they're still available to buy even after all this time.

 

[Dashmellow]

There are two types of Mobius case which allow for the two types of lens module available. The D and C2 modules have a thin base, whereas the original A has a thicker base. The different cases have different spaced out tabs that hold the sensor module in place. It is quite easy to remove these with a craft knife so that the module is free to move front-to-back. As @Dashmellow says, the easiest and most secure way to install the varifocal lens is with the back flange tight against the front of the plastic Mobius case.

I had one case where I did these modifications, then tried going back to using a D lens for a while. The lens module was then slightly loose within the case since there were no tabs to hold it in place. At least replacement cases are cheap, and thankfully they're still available to buy even after all this time.

Thanks, I remember that now.

 

[joe384]

My original case came with a C2 lens, I have however just received my new mobius case so I will just screw the lens in as DashMellow suggests.
I think the tabs look the same on this case