'Heath Robinson' style polarizing filter - just £3.99

KevBro

KevBro

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Joined
Feb 28, 2015
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Location
Leyland, Lancs. UK
Country
United Kingdom
Dash Cam
Mini 0805
below are 3 pics of my cheap and nasty, yet efficient filter.
my second attempt will be better - especially when I get some matt black paint rather than marker pen!

it is very lightweight and simply pushes over the outer lens.
the fiber washer was simply super glued to the film. (one piece of film can make 2 filters)
later this week I will show how I have fitted my cam, with an on/off switch, plus a black surround that will hide it all on my windscreen.

cam_1.jpg


cam_2.jpg


cam_3.jpg
 
Ordered my polarising film ready for my attempt. Got to be worth a try!

Thanks for the tip!
 
KevBro said:
being a linear polarizer you have to try to try it at different angles through a 90 deg range.
mine works ok, but I'm thinking a circular polarizer might be best after all.
see this link: http://www.bobatkins.com/photography/technical/polarizers.html
Click to expand...
Actually a linear polariser is better that a circular for a dashcam as it cuts out slightly less light. The circular part (quarter wave plate) has no useful function for a dashcam.

With both linear and circular polarisers you need to set the correct angle which for cutting out dashboard reflections is always 0 degrees or vertical so if you have a rectangular piece of linear polariser sheet you will need to mount it exactly vertical or horizontal depending which way it is polarised, there is no need to make it adjustable. If you have a proper circular polariser filter then you always mount it with the white line either at the very top or at the bottom so that the polarisation is exactly vertical.
 
Last edited by a moderator:
Numone said:
Yeah, it was your DIY build that so impressed me I needed to get one on the 0805! Unfortunately, that filter is circa £55 in the UK, which is 90% of the cost of the cam itself, so I looked for a slightly cheaper option!
Click to expand...
You could try a mini 0806 CPL, much cheaper and if you can mount a magnet on the inside of your mini 0805 case then it may work just as well as it does on the mini 0806...

https://www.ebay.co.uk/itm/351321611081
 
Nigel said:
You could try a mini 0806 CPL, much cheaper and if you can mount a magnet on the inside of your mini 0805 case then it may work just as well as it does on the mini 0806...

https://www.ebay.co.uk/itm/351321611081
Click to expand...

Well, I'll be....! Thanks Nigel! I don't fancy dismantling the cam case, but I can probably mount it with some high-tack double-sided tape, so I'm going to give that a go! ;)
 
I'd glue it, glue worked fine for my mini 0803, white line goes exactly at top unless they have misassembled it, which is quite possible so check first. Ideally you take them off at night but in reality you will never get around to it.
 
Nigel said:
I'd glue it, glue worked fine for my mini 0803, white line goes exactly at top unless they have misassembled it, which is quite possible so check first. Ideally you take them off at night but in reality you will never get around to it.
Click to expand...

Thanks for the additional tips, Nigel. Ordered and on its way!:)
 
If anyone fancies a play, it looks like this 20 x 15 x 3 ring magnet would fit almost perfectly in place of the 0805 lens barrel and the 0806 CPL would clamp onto it very firmly: https://www.ebay.co.uk/itm/380833112075
The lens barrel is a separate piece of plastic that can be removed allowing a clean fit, would need a bit of glue to hold it in place.
 
Numone said:
Well, I'll be....! Thanks Nigel! I don't fancy dismantling the cam case, but I can probably mount it with some high-tack double-sided tape, so I'm going to give that a go! ;)
Click to expand...

I'm following all this with interest and have also been considering one of the 0806 filters.
as a mount I intend using a steel washer I modified that fits very snugly over the existing lens barrel, which seems to be 18mm
the washer is only 1 mm thick x 25 mm OD and it was a delicate job filing out the original 10 mm hole as it needs to fit tightly.

the ebay sellers say that the filter is 24mm diameter, but don't say if that is outside diameter, or the glass itself.
either way I doubt it would be more than 28mm and as such would possibly cover a couple of the cooling holes.

0805.jpg
 
KevBro said:
I'm following all this with interest and have also been considering one of the 0806 filters.
as a mount I intend using a steel washer I modified that fits very snugly over the existing lens barrel, which seems to be 18mm
the washer is only 1 mm thick x 25 mm OD and it was a delicate job filing out the original 10 mm hole as it needs to fit tightly.

the ebay sellers say that the filter is 24mm diameter, but don't say if that is outside diameter, or the glass itself.
either way I doubt it would be more than 28mm and as such would possibly cover a couple of the cooling holes.
Click to expand...
I suspect that you have not have realised that the mini 0806 CPL is not a magnet so will not stick to your steel washer, the magnet is inside the mini 0806 so the steel CPL sticks to the mini 0806.
 
ooops ... there is no fool like an old fool Nigel! ... I got that all ar*se about face!
no matter, I have some magnetic material, and will try 4 small bits of that when my filter arrives.
what a waste of a nice bit of filing though.
 
I have managed to glue some thin magnetic material from a fridge magnet onto my washer, and am pleased with the result.
It is surprisingly strong, and should certainly hold the CPL when I get it- it just needs trimming to suit.

to me this is far better than gluing, or sticky-taping stuff onto the camera body (may void warranty)
and has the added advantage that I can easily rotate the CPL and remove it for night driving.

my only concern is that since it protrudes slightly above the lens barrel, and the CPL does not go onto the body, that the field of view may be hampered a bit.
if it does it I think it would be quite minor.
thanks again Nigel for spotting my initial boo-boo!

0805_1.jpg

0805_2.jpg
 
KevBro said:
my only concern is that since it protrudes slightly above the lens barrel, and the CPL does not go onto the body, that the field of view may be hampered a bit.
Click to expand...
It is a little thick, but if you stick to 21:9 cinema mode then I reckon it will be fine. May be OK anyway as the 0805 has a narrower field of view than the 0806 but I suspect the corners may be darkened on 16:9 modes.

Well done, if it works then it's a nice solution, I would have guessed that a fridge magnet wouldn't be strong enough.
 
KevBro said:
I have managed to glue some thin magnetic material from a fridge magnet onto my washer, and am pleased with the result.
It is surprisingly strong, and should certainly hold the CPL when I get it- it just needs trimming to suit.

to me this is far better than gluing, or sticky-taping stuff onto the camera body (may void warranty)
and has the added advantage that I can easily rotate the CPL and remove it for night driving.

my only concern is that since it protrudes slightly above the lens barrel, and the CPL does not go onto the body, that the field of view may be hampered a bit.
if it does it I think it would be quite minor.
thanks again Nigel for spotting my initial boo-boo!

0805_1.jpg

0805_2.jpg
Click to expand...
Yeah, the CPL arrived and I think you'll have a problem with the thickness of that magnet and washer combo mate; you'll deffo see the lens in the corners of the pic as the magnet and washer combined extend the lens ring into the field of view..
 
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