Oddball Dashcam Lens / general Photography question.

[Submariner1]

The optional Circular Polarising Lens for my new Dashcam is circa £30. Looks like rather naff unbranded stuff.
Unfortuneately its an odd size being 30mm. And I can’t find a budget filter in 30mm with a good reputation, but there are a few great performing budget 52mm CPL filters.

So, I had the idea, of getting one of those £5 “step up filter rings”, that takes it from 30mm to 52mm.


And then buying a VFM budget filter, with a reasonably decent Reputation such as a Hoya or Pentax Polarising filter. Circa £9 - £16

And as I have one normal camera lens, that uses a 52mm filter, and the next best alternative Dashcam also uses 52mm filters. My thoughts were, if this Dashcam turns out to be a crap Dashcam; Then at least I could change it for the other Dash-cam, and still use the 52mm CPL filter.

Or
worst case it could be useful for my normal backup camera lens.

I.e. I wont be left with a redundant oddball sized 30mm CPL filter .

It also saves a few £sss.

The question is would a “step up ring” be a good thing (sort of acting as a lens hood) or a bad thing.?

Likewise if it would be good, would it be even better getting 2 rather than one, i.e 30-43mm and adding a 43- 52mm to effectively produce a cone, rather than the flatish one pictured above?
Any views Appreciated?

Other question does putting the dashcam lens near the windshield, help reduce polarisation or make it worse ?
Difficult to experiement with sticky pad brackets . So what did you find?

Peter

 

[LostKiwi]

A step up will work fine aside from potentially making the camera harder to mount.

 

[Submariner1]

A step up will work fine aside from potentially making the camera harder to mount.

Thanks LK,

Should I be trying to get the lens as close as possible to the windscreen?

Quite a few factors coming into play, as I was not planning on taking the filter off at night.
Things like the glancing flash, just as an oncoming car headlight strikes the windscreen, and then dissapears.

 

[LostKiwi]

The closer the lens to the windscreen the less reflections but if you have can polariser it makes little difference. Why not try it with or without the polariser and go from there?
I'd be more concerned about the reduced light levels (1-2 stops depending on type) using a polariser than the momentary flares as headlights reflect of the lens.

 

[Frontstep]

I have some in a draw somewhere from an old video camera I shall try one.

 

[Submariner1]

The closer the lens to the windscreen the less reflections but if you have can polariser it makes little difference. Why not try it with or without the polariser and go from there?
I'd be more concerned about the reduced light levels (1-2 stops depending on type) using a polariser than the momentary flares as headlights reflect of the lens.

Understand,
The Vico arrived today.
Memory card tomorrow.
Got to order the CPL filter and step up holder this afternoon.
Just wanted to check it really is a 30mm diam filter, not a 30mm lens.

The closer the lens to the windscreen the less reflections but if you have can polariser it makes little difference. Why not try it with or without the polariser and go from there?
I'd be more concerned about the reduced light levels (1-2 stops depending on type) using a polariser than the momentary flares as headlights reflect of the lens.