Lens Closer To Windshield Better?

[ftpGuy]

Hey gang!

I may actually get around to mounting my dashcam today and was wondering if it was better to use the "thin" mounting plate when allowed vs. the "thick" plate. Another words, is it better to have the lens as close to the windshield as possible? And if so, why? Is there that much difference?

Thanks in advance for any replies.

 

[jokiin]

The thick mount is for vertical windows, use the thin mount for a regular front window install

 

[kuoh]

The closer you can get the lens to the windshield, the less reflection of the dash and surrounding areas you'll have in the recordings. This is very noticeable if you have a light colored dash & trim on a well lit day. However, if your camera is one that has a highly reflective body or trim ring, then it could also be a detriment, as you will see more reflections from it the closer you get to the windshield.

KuoH

Another words, is it better to have the lens as close to the windshield as possible? And if so, why? Is there that much difference?

 

[Dashmellow]

The notion that one should always mount a dash camera with the lens as close to the glass as possible to minimize reflections is a myth. Having the lens very close to the glass can actually make reflections of the dashboard worse, much worse. Ask anyone who purchased a SG9665GC or B40/A118 who has discovered that they now need to spend an extra forty bucks on a specialized CPL filter or buy a dash mat because reflections that previously may have simply been an annoyance with a different camera are now a major problem.

The question of whether a camera should be mounted closer to the glass or farther away to minimize reflections depends a great deal on the particular vehicle the camera is mounted in. Factors include the rake angle and curvature of the windscreen, the shape, angles, texture and color of one's dashboard and the focal length/FOV of the lens.

My personal experience going on six years of multiple dash camera ownership is that the more slope there is in the glass, the farther the camera should be from the windscreen, while the more vertical the glass, the closer it should be.

 

[BrianJ]

In my case, I had to use the thicker mount as I could not aim the lens high enough (with CPL filter on) using the thinner mount.

 

[Dashmellow]

It's nice that the SG comes with that thicker mounting plate if needed.

 

[Deleted member 46308]

The notion that one should always mount a dash camera with the lens as close to the glass as possible to minimize reflections is a myth. Having the lens very close to the glass can actually make reflections of the dashboard worse, much worse. Ask anyone who purchased a SG9665GC or B40/A118 who has discovered that they now need to spend an extra forty bucks on a specialized CPL filter or buy a dash mat because reflections that previously may have simply been an annoyance with a different camera are now a major problem.

The question of whether a camera should be mounted closer to the glass or farther away to minimize reflections depends a great deal on the particular vehicle the camera is mounted in. Factors include the rake angle and curvature of the windscreen, the shape, angles, texture and color of one's dashboard and the focal length/FOV of the lens.

My personal experience going on six years of multiple dash camera ownership is that the more slope there is in the glass, the farther the camera should be from the windscreen, while the more vertical the glass, the closer it should be.

That has been my experience, exactly. For comparison purposes, I mounted my Panorama S on the opposite side of the windshield from my SG96655GC. The comparison for reflections was not even close, as the Panorama S video showed very little, if any, reflections even in direct sunlight.

The SG9665GC on the other hand had a lot of reflections from the hood, dash, and other objects. The CPL filter solved most, but not all of those reflection problems. I opted to leave the SG9665GC mounted because of the form factor, and I just like the way the camera attaches to the windshield.

 

[DT MI]

The notion that one should always mount a dash camera with the lens as close to the glass as possible to minimize reflections is a myth. Having the lens very close to the glass can actually make reflections of the dashboard worse, much worse. Ask anyone who purchased a SG9665GC or B40/A118 who has discovered that they now need to spend an extra forty bucks on a specialized CPL filter or buy a dash mat because reflections that previously may have simply been an annoyance with a different camera are now a major problem.

The question of whether a camera should be mounted closer to the glass or farther away to minimize reflections depends a great deal on the particular vehicle the camera is mounted in. Factors include the rake angle and curvature of the windscreen, the shape, angles, texture and color of one's dashboard and the focal length/FOV of the lens.

My personal experience going on six years of multiple dash camera ownership is that the more slope there is in the glass, the farther the camera should be from the windscreen, while the more vertical the glass, the closer it should be.

That has been my experience, exactly. For comparison purposes, I mounted my Panorama S on the opposite side of the windshield from my SG96655GC. The comparison for reflections was not even close, as the Panorama S video showed very little, if any, reflections even in direct sunlight.

The SG9665GC on the other hand had a lot of reflections from the hood, dash, and other objects. The CPL filter solved most, but not all of those reflection problems. I opted to leave the SG9665GC mounted because of the form factor, and I just like the way the camera attaches to the windshield.

I have to add my concurrence here as well. I found this to be true when I went from a G1W-x to the SG9665GC - reflections increased significantly.

To confirm to myself I did some experimentation with a camcorder moving it through the passenger compartment from the driver's eye position to the G1W position to the SG9665GC position and with every change of location the reflections increased. I'll see if I can find the video and post it to demonstrate.

 

[Dashmellow]

That has been my experience, exactly. For comparison purposes, I mounted my Panorama S on the opposite side of the windshield from my SG96655GC. The comparison for reflections was not even close, as the Panorama S video showed very little, if any, reflections even in direct sunlight.

The SG9665GC on the other hand had a lot of reflections from the hood, dash, and other objects. The CPL filter solved most, but not all of those reflection problems. I opted to leave the SG9665GC mounted because of the form factor, and I just like the way the camera attaches to the windshield.

Thanks to my purchase of the SG9665GC I am now the proud owner of a dash mat and a CPL. The black suede dash mat I found (and enhanced) is extremely and surprisingly effective for ameliorating the reflection problem. In fact, alone it almost precludes the need for the CPL.

 

[Deleted member 46308]

Thanks to my purchase of the SG9665GC I am now the proud owner of a dash mat and a CPL. The black suede dash mat I found (and enhanced) is extremely and surprisingly effective for ameliorating the reflection problem. In fact, alone it almost precludes the need for the CPL.

Small things seem to irritate me, especially things I have to constantly move about. I do see the advantage of a dash mat, but that would probably push me over the edge. With the CPL I started noticing a small curtain effect on all of the corners, so I stopped using it and am now just going without the filter entirely. I have found this effect to be the same on different vehicles as well.

 

[Dashmellow]

I almost didn't buy a dash mat because I thought it would look hideous but it doesn't look bad at all and now I hardly even notice it. It was a pain to get the thing installed properly, especially in making sure the defroster vent wasn't hindered by the mat but it hasn't required any further attention since. I've had some problems with my SG9965GC and am currently testing out a replacement unit @jokiin and @Pier28 sent me without using the CPL and I'm not quite sure if I will be reinstalling it either. My preference after lots of experimentation with CPLs on dash cams is to not use them if it can be avoided but the SG is very challenging in that regard, so time will tell.

 

[Dashmellow]

I have to add my concurrence here as well. I found this to be true when I went from a G1W-x to the SG9665GC - reflections increased significantly.

I think a lot of us had the same experience, hence the introduction of the CPL option. This camera has such a problem with this issue that it almost needs to include a CPL with the purchase, although that would likely bump the price out of its class range.

 

[DT MI]

...With the CPL I started noticing a small curtain effect on all of the corners,...

Is this what you're referring to?



I've got exactly the same thing with both cameras (front and rear). At first I thought it might be due to the CPL being a bit off-center so I turned it 180 degrees but the vignetting remained in the same position so that's not it. I've noticed in some other videos posted with the CPL that it occurs on the left side corners instead of the right. Maybe @jokiin can provide a bit of insight.

It doesn't bother me and is better than reflections.

 

[Dashmellow]

My understanding is that there will be a revised version of the CPL available that will eliminate the vignetting problem as well as hold more securely over the lens.

 

[Deleted member 46308]

Is this what you're referring to?

View attachment 19725

I've got exactly the same thing with both cameras (front and rear). At first I thought it might be due to the CPL being a bit off-center so I turned it 180 degrees but the vignetting remained in the same position so that's not it. I've noticed in some other videos posted with the CPL that it occurs on the left side corners instead of the right. Maybe @jokiin can provide a bit of insight.

It doesn't bother me and is better than reflections.

Yes, that is exactly what I was referring to in my post. For some reason mine appears on all of the corners. I have an early edition of the CPL without the lens glued. And I have a later one where there is no adjustment needed. I get the same result with both. I would agree that given those choices it would be better than a reflection. However, it became a personal irritant so I just stopped using the filter.

 

[DT MI]

I think a lot of us had the same experience, hence the introduction of the CPL option. This camera has such a problem with this issue that it almost needs to include a CPL with the purchase, although that would likely bump the price out of its class range.

Not just this camera - if anything the A118-C in my wife's car is worse but that could be the car and not the camera.

I found my video(s) I mentioned earlier in this thread and did a few frame grabs. The first image below shows where I had the G1W-x and SG9665GC. The next four show the reflections from 1) Driver's eye view, 2) G1W-x view, 3) SG9665GC view and 4) With the camcorder right against the glass. (You'll notice the SG is mounted under the sensor housing so there's a couple of inches between it and the glass.)

It's pretty obvious that the closer to the glass and the higher you get the worse the reflections.




Driver's eye view:



G1W view



SG9665GC view




Camera on glass view

 

[Mikk36]

I'm guessing that it should be possible to attach some kind of black matte plastic shield to the bottom side of the lens to block any and all reflections from the inside of the car, if the camera is so close to the windshield (in the case of SG9665GC).

 

[DT MI]

I'm guessing that it should be possible to attach some kind of black matte plastic shield to the bottom side of the lens to block any and all reflections from the inside of the car, if the camera is so close to the windshield (in the case of SG9665GC).

I seem to recall someone posting about that somewhere - either here in the SG9665GC thread or maybe the B40/A118 forum.

 

[Street Guardian USA]

The vignetting is due to the 3D printer tolerances so it happens to a few. I did not have the problem on my original test sample. This is being addressed and corrected in the upcoming next CPL batch coming in January. I will replace anyone that is experiencing the issue with the new slightly adjusted design.

 

[DT MI]

The vignetting is due to the 3D printer tolerances so it happens to a few. I did not have the problem on my original test sample. This is being addressed and corrected in the upcoming next CPL batch coming in January. I will replace anyone that is experiencing the issue with the new slightly adjusted design.

Now that is customer service as it should be.

Can you share any of the specifics as to the cause?