CPL Status

I thought the CPL was going to be fixed in the perfect position? It looks to be rotatable?

The DDPai M6+ CPL is fixed, so why does one manufacturer work out the best orientation and another leave it up to the user?
I'm fairly sure there must be just one optimum position for all users rather than us all constantly worrying if we've got it "just so" and endlessly fiddling?
 
DavidUK said:
I thought the CPL was going to be fixed in the perfect position? It looks to be rotatable?

The DDPai M6+ CPL is fixed, so why does one manufacturer work out the best orientation and another leave it up to the user?
I'm fairly sure there must be just one optimum position for all users rather than us all constantly worrying if we've got it "just so" and endlessly fiddling?
Click to expand...
I hate if I have to fiddle with it. I will never think I got it right and will be obsessed with trying to get it just right. Not good for my nerves.
 
So, is this yet another pre-production version on the Viofo site? Or are the slots the glass sits in purely to make the housing as small as possible, height-wise?

Screen Shot 2016-11-25 at 23.37.08.png
 
It can not to be rotatable since it covers whole lens.:(
 
estore009 said:
It can not to be rotatable since it covers whole lens.:(
Click to expand...
It's not suppose to rotate .

I looks there first slide the lens into positions you see. Then there can turn it with finger, until the filter give the best result (less glare/reflection). Then there seal it, so it can't rotate.
So there is no more need to make more adjustment.

Street Guardian USA said:
Final production CPL will be fixed in place.
Click to expand...
 
Well can we please see it for sale in the UK soon so as to stop me buying more and more DIY polarising bits!

So far, 1 mobile phone filter set, 1 sheet polarising film, 25 shim washers, 18 neodymium magnets, 2 PL camera filters!! I'm almost up to £15 in expenditure so far and still not entirely happy with my work! :confused:

Still, it's been interesting. o_O
 
DavidUK said:
Well can we please see it for sale in the UK soon so as to stop me buying more and more DIY polarising bits!

So far, 1 mobile phone filter set, 1 sheet polarising film, 25 shim washers, 18 neodymium magnets, 2 PL camera filters!! I'm almost up to £15 in expenditure so far and still not entirely happy with my work! :confused:

Still, it's been interesting. o_O
Click to expand...

Well, if you pm me with an address I will send you one of my diy builds. I love my latest version.

After grinding an edge flat on my washer, I blued the steel and then painted flat black. Very good result. I leave mine on 24/7.
 
@Bob Smith42 - Very kind offer, but first, let's see your design? Are you using your 2x2 film? Is it PL or CPL? I'm using shim washers 21mm x 15mm in a variety of thicknesses 0.1mm; 0.3mm; 0.5mm; 1mm and various magnets. From left to right below...

21mm watch crystal with Samsung S6 CPL film on front and 21x15x0.1 shim washer rear; 16mm dia glass element of cheap mobile phone (with surplus glue around it) with S6 CPL film front and washer rear; 16mm PL film from cheap mobile phone sandwiched between two washers. All held on my two glued 5x5 neo magnets each side of lens...

Screen Shot 2016-11-26 at 18.11.50.png Screen Shot 2016-11-26 at 18.22.30.png

Night time clip below with the right hand PL filter in place (but not sure about ideal rotation yet, not that it matters at night so much). Check out around 30 seconds in when "Paradise" is playing in the car and coincidentally I'm driving through Paradise! Hold it! No sound on first clip!? Why is that? Ah... "This video previously contained a copyrighted audio track. Due to a claim by a copyright holder, the audio track has been muted." That was quick!! :rolleyes:


This one was without any filter in place for comparison...



By the way, looking through CPL and PL at the windscreen in my car in daylight, the PL, to my naked eye, is more effective at reducing reflections than the CPL.
 
Last edited:
DavidUK said:
@Bob Smith42 - Very kind offer, but first, let's see your design? Are you using your 2x2 film? Is it PL or CPL? I'm using shim washers 21mm x 15mm in a variety of thicknesses 0.1mm; 0.3mm; 0.5mm; 1mm and various magnets. From left to right below...

21mm watch crystal with Samsung S6 PL film on front and 21x15x0.1 shim washer rear; 16mm dia glass element of cheap mobile phone (with surplus glue around it) with S6 PL film front and washer rear; 16mm CPL film from cheap mobile phone sandwiched between two washers. All held on my two glued 5x5 neo magnets each side of lens...

View attachment 27603 View attachment 27604

Night time clip below with the right hand CPL filter in place (but not sure about ideal rotation yet, not that it matters at night so much). Check out around 30 seconds in when "Paradise" is playing in the car and coincidentally I'm driving through Paradise! Hold it! No sound on first clip!? Why is that? Ah... "This video previously contained a copyrighted audio track. Due to a claim by a copyright holder, the audio track has been muted." That was quick!! :rolleyes:


This one was without any filter in place for comparison...



By the way, looking through PL and CPL at the windscreen in my car in daylight, the CPL, to my naked eye, is more effective at reducing reflections than the linear PL.
Click to expand...

I don't know about filters. but my guess was the circular was just a physical dimension, not a filter attribute. in any case, mine are cut from those 2 inch films and taped on back the washer.I set the orientation in sunlight, and its fixed.

Your design looks good, better if you sprayed black matte paint. my washers are thick, so when I cut an edge flat it sticks to the magnet at the top.I use round magnets overhanging the top edge. you need a gps module to make room for the magnet.

I'm not planning on posting a picture, but if someone wants one I will send it any they can post pictures.I made five extras.
 
broadbean said:
https://en.wikipedia.org/wiki/Polarizer#Circular_polarizers
Click to expand...

Thanks. I checked my polarizing film. Mine is linear only.

According to the website, an CPL is first linear (requiring orientation) and adds a circular layer. I do not know if the Viofo camera requires circular polarized light for any feature, nor what is the benefit of a circular layer in our dash cam application.

I am happy with my linear polarized filter because it eliminates most dash and glass reflection. A more detailed/costly design does not concern me because I was always planning to use the official Viofo filter when available.
 
I see that StreetGuardian has an almost identical unit listed on Amazon that can ship on December 1st. It claims to be 3D printed and require no adjustment but has a rather scary price of $39.95

If the dashcam manufacturer had spent just a little more on the lens to have it anti-reflective coated, this entire discussion and need for an add-on filter could have been avoided. As higher resolution devices are more common the quality of ALL optical components becomes more important. I hope that inappropriate cost cutting does not continue with this or other dashcam manufacturers.

If my link doesn't work search Amazon for item B01800HH0M
 
DavidUK said:
@Bob Smith42 - Very kind offer, but first, let's see your design? Are you using your 2x2 film? Is it PL or CPL? I'm using shim washers 21mm x 15mm in a variety of thicknesses 0.1mm; 0.3mm; 0.5mm; 1mm and various magnets. From left to right below...

21mm watch crystal with Samsung S6 CPL film on front and 21x15x0.1 shim washer rear; 16mm dia glass element of cheap mobile phone (with surplus glue around it) with S6 CPL film front and washer rear; 16mm PL film from cheap mobile phone sandwiched between two washers. All held on my two glued 5x5 neo magnets each side of lens...

View attachment 27603 View attachment 27604

Night time clip below with the right hand PL filter in place (but not sure about ideal rotation yet, not that it matters at night so much). Check out around 30 seconds in when "Paradise" is playing in the car and coincidentally I'm driving through Paradise! Hold it! No sound on first clip!? Why is that? Ah... "This video previously contained a copyrighted audio track. Due to a claim by a copyright holder, the audio track has been muted." That was quick!! :rolleyes:


This one was without any filter in place for comparison...



By the way, looking through CPL and PL at the windscreen in my car in daylight, the PL, to my naked eye, is more effective at reducing reflections than the CPL.
Click to expand...
 
Last edited:
N4OZ said:
I see that StreetGuardian has an almost identical unit listed on Amazon that can ship on December 1st. It claims to be 3D printed and require no adjustment but has a rather scary price of $39.95

If the dashcam manufacturer had spent just a little more on the lens to have it anti-reflective coated, this entire discussion and need for an add-on filter could have been avoided. As higher resolution devices are more common the quality of ALL optical components becomes more important. I hope that inappropriate cost cutting does not continue with this or other dashcam manufacturers.

If my link doesn't work search Amazon for item B01800HH0M
Click to expand...

The SG9665GC does have thin film anti-reflective multi-coatings which do in fact reduce "some" reflections but such lens coatings have more to do with the optical transfer function of an optic than for reducing or eliminating severe glare and reflection off a surface plane. There is no lens coating available that will perform the same function as an optical polarizer so equating the two is basically an apples and oranges kind of thing.
 
Last edited:
N4OZ said:
I see that StreetGuardian has an almost identical unit listed on Amazon that can ship on December 1st. It claims to be 3D printed and require no adjustment but has a rather scary price of $39.95

If the dashcam manufacturer had spent just a little more on the lens to have it anti-reflective coated, this entire discussion and need for an add-on filter could have been avoided. As higher resolution devices are more common the quality of ALL optical components becomes more important. I hope that inappropriate cost cutting does not continue with this or other dashcam manufacturers.
Click to expand...

the scary price is due to the scary cost, we pay far too much for those which is one of the drivers behind a mass produced filter becoming available (the filter Viofo will be using is actually ours, we've shared it with them to increase the quantity so that we can further lower the cost)

as mentioned by @Dashmellow above the anti reflective coatings on the lens are already there but they won't eliminate windscreen reflections, that is a result of physics, not cost cutting
 
You must log in or register to reply here.
Back
Top