VS1 vs RTC300

[cozzykim]

I've been thinking about asking Viofo for a telephoto version of the VS1 that I use as a rear view camera in my Boxster, mounted on the clear wind deflector.

Though the RTC300 looks good, it's no use to me, as I already 'invested' in two VS1s, one front, one rear.

Maybe a daft question? Can we have a narrower angle VS1 please?

 

[Search&Rescue]

telephoto version of the VS1

Does this physically exist?

 

[cozzykim]

Nope, that's why I'm asking whether it's possible.

 

[Nigel]

Nope, that's why I'm asking whether it's possible.

I think it is quite a good idea, although different people are going to want different amounts of "zoom" to match their car?

What field of view would you want?

I suspect the RTC300 would be rather narrow for your rear use, the field of view must be approximately 1/2.6 of a normal VS1, it is meant as a telephoto, not just a narrow field of view camera.

Having looked at your rear image,

It appears that you want most of that width, it is the height you don't need, so a 21:9 or maybe wider aspect ratio resolution mode would be good, and that can be done via firmware update...

 

[cozzykim]

That's actually an excellent point Nigel, thanks.

It's only slightly inconvenient to have the VS1 mounted on the wind deflector, but I was also considering having the narrower field of view for having the camera mounted on the windscreen facing rearwards.

 

[Nigel]

That's actually an excellent point Nigel, thanks.

It's only slightly inconvenient to have the VS1 mounted on the wind deflector, but I was also considering having the narrower field of view for having the camera mounted on the windscreen facing rearwards.

Given that it is a 2K camera, it is probably already usable mounted on the windscreen facing rearwards, I guess you don't have good visibility out the rear sides, so the image wont look great unless you zoom in, but there is enough resolution to work as a rear camera like that.

I think for that setup, instead of a telephoto version, I would go for a 4K wide angle version, which would hopefully give a reasonable view of the interior, including the driver+passenger, and a reasonable view out the rear. The view out the rear won't be quite as wide as with the rear mounted camera due to the viewing angles, and the headrests may get in the way, especially if you mount it low so that you get the driver+passenger in the image? But it should function well enough as a rear dashcam, probably with slightly more resolution than you have at the moment, but with narrower view out the rear.

Of course there isn't a 4K version of the VS1 available at the moment, but a little encouragement to Viofo may give results

 

[cozzykim]

The very last thing I want is footage of me + passenger, so I think I'll leave it as it is for now.

 

[Dashmellow]

I've been thinking about asking Viofo for a telephoto version of the VS1 that I use as a rear view camera in my Boxster, mounted on the clear wind deflector.

Though the RTC300 looks good, it's no use to me, as I already 'invested' in two VS1s, one front, one rear.

Maybe a daft question? Can we have a narrower angle VS1 please?

If you have some DIY skills you can likely install your own telephoto lens in a VS1 in place of the one it shipped with at the factory. Quite a few DCT members have doing mods like this for years and I'm sure some will be happy to advise you if you wanted to take a project like this on. It can be a bit challenging but all in all it is not that hard to do. The M12 type lenses that come in dash cams screw into a holder and the project involves opening up the camera, unscrewing the existing lens, screwing the new lens in, focusing it and then putting the camera back together.

Sounds like the best option would be the 12 Megapixel 8mm. ƒ1.7 4K lens from Jetsun on AliExpress. I has a wider angle of view than the RTC300 if you wanted to try this. There is a 6mm lens available that might also work for you with this sensor.

These kind of modifications are not everyone's cup of tea but it may be something to consider.

https://www.aliexpress.us/item/2251832607836348.html?spm=a2g0o.productlist.main.5.328b7a5bQTpIxf&algo_pvid=0d3138ce-76b2-4a12-9ea3-6ae6896e9f7b&algo_exp_id=0d3138ce-76b2-4a12-9ea3-6ae6896e9f7b-2&pdp_npi=4@dis!USD!19.00!19.00!!!19.00!19.00!@2103246417192644970478236ea2df!63864844774!sea!US!0!AB&curPageLogUid=VjlLmTCS9aDc&utparam-url=scene:search|query_from:#nav-specification

 

[DCS Australia]

If you have some DIY skills you can likely install your own telephoto lens in a VS1 in place of the one it shipped with at the factory. Quite a few DCT members have doing mods like this for years and I'm sure some will be happy to advise you if you wanted to take a project like this on. It can be a bit challenging but all in all it is not that hard to do. The M12 type lenses that come in dash cams screw into a holder and the project involves opening up the camera, unscrewing the existing lens, screwing the new lens in, focusing it and then putting the camera back together.

Sounds like the best option would be the 12 Megapixel 8mm. ƒ1.7 4K lens from Jetsun on AliExpress. I has a wider angle of view than the RTC300 if you wanted to try this. There is a 6mm lens available that might also work for you with this sensor.

These kind of modifications are not everyone's cup of tea but it may be something to consider.

https://www.aliexpress.us/item/2251832607836348.html?spm=a2g0o.productlist.main.5.328b7a5bQTpIxf&algo_pvid=0d3138ce-76b2-4a12-9ea3-6ae6896e9f7b&algo_exp_id=0d3138ce-76b2-4a12-9ea3-6ae6896e9f7b-2&pdp_npi=4@dis!USD!19.00!19.00!!!19.00!19.00!@2103246417192644970478236ea2df!63864844774!sea!US!0!AB&curPageLogUid=VjlLmTCS9aDc&utparam-url=scene:search|query_from:#nav-specification

Hi, thanks for sharing.

So would this part fit by replacing the existing one on the VS1? Description says 8mm, but I'd be happy know the exact part that would be an easy swap.

Cheers, Albert

 

[Dashmellow]

Hi, thanks for sharing.

So would this part fit by replacing the existing one on the VS1? Description says 8mm, but I'd be happy know the exact part that would be an easy swap.

Cheers, Albert

I've done quite a few lens swaps on a variety of dash cams but to be honest I don't own a VS1 and have never handled one in person, so I can't speak to this camera with authority. Generally speaking though, all dash cams are similar enough that the technique is more or less the same with all of them.

The primary concern is to chose a lens that is compatible with the camera's sensor in terms of coverage. Each lens projects a cone of light of a particular size onto the sensor and this needs to be large enough to exceed the size of the sensor or you will end up with vignetting. The lens also needs to have a BFL (back focal length) that will work with the depth of the screw-in lens holder so that you can focus the lens properly. BFL is the distance between the rear lens element and the sensor when the lens is in focus. If the holder is too long you won't be able to screw the lens in far enough to focus and if it is too short (or the lens barrel too long) you could end up screwing the lens in too far and damage the sensor.

Much of this is often trial and error but I believe this lens should work fine with the VS1 and it happens to be an excellent 8mm lens that some of have used in other 2K and 4K cameras with good results.

Pretty much all dash cams use M12 lenses. M12 means "metric 12 mm". An M12 lens has male metric threads with 0.5 mm pitch and is 12 mm in diameter. It will screw into virtually any dash cam on the market. As mentioned above the question is whether the barrel is long enough to fit the existing female threaded holder and this is partly determined by the optical specifications of the lens. (again, the BFL thing is how far the rear element of the lens needs to be for the lens to be in focus).
M12 lenses are also called S-Mount lenses as well as board lenses and they were originally designed for CCTV cameras.

Anyway, there is almost always a certain amount of wiggle room when you install and focus an aftermarket M12 lens on an already existing camera and an aftermarket like the 8mm lens (the focal length is 8mm). A similar 6mm has been used with good success on cameras such as the Viofo A139 Pro which @TonyM used HERE when he converted his A139 Pro.

So the answer is I don't know for sure if it would work but like I said, I believe it will. The thing to know is there is no such thing as an "exact part" when doing a mod like this because the camera was never designed with a DIY lens swap in mind. Experimentation is really part of the fun and excitement of doing dash camera modifications like this but it is not a perfect, exact science because some things are just knowable until you actually take the camera apart and do the swap.

You'll find various threads here on DCT and videos on YouTube that can be very instructive.

 

[DCS Australia]

Thanks Dashmellow for your in detail explanation. I think it's a great idea to consider a mod. So many dashcams in this world have good CMOS but often come with poor and cheap lenses.

I will definitely give it a shot! Will keep in touch.

 

[Dashmellow]

Thanks Dashmellow for your in detail explanation. I think it's a great idea to consider a mod. So many dashcams in this world have good CMOS but often come with poor and cheap lenses.

I will definitely give it a shot! Will keep in touch.

You're welcome!

Not every camera comes with a poor and cheap lens. The VS1 certainly doesn't but sometimes you want to change what the camera can do.

I'm excited to hear you are willing to give this a go. Let us know how it goes !

 

[DCS Australia]

I am not sure I will do it on the VS1. Maybe I will try with another first and then move up? from there. But yeah! I think it's cheaper to do a mod than buying something new (especially when Blackvue 970X Plus has NO HDR) at a significantly higher price.

 

[Dashmellow]

I am not sure I will do it on the VS1. Maybe I will try with another first and then move up? from there. But yeah! I think it's cheaper to do a mod than buying something new (especially when Blackvue 970X Plus has NO HDR) at a significantly higher price.

Trying it first on a different camera to get your feet wet with the basics sounds like a really smart and good idea.

 

[DCS Australia]

Thanks Dashmellow.

I am choosing between one of my IMX675s.

Tough decision!!

 

[DCS Australia]

Trying it first on a different camera to get your feet wet with the basics sounds like a really smart and good idea.

Hey Dashmellow,

I've decided to try out something else, but I thought I'd ask for your advice.

My current lens is F1.8 and I am thinking of getting a Starlight lens with F1.0 and a slightly narrower FOV. I am hoping that this will improve light sensitivity and clarity.

The fitting spec is not exactly 1:1 fit. It should be OK, or?

 

[Dashmellow]

Hey Dashmellow,

I've decided to try out something else, but I thought I'd ask for your advice.

My current lens is F1.8 and I am thinking of getting a Starlight lens with F1.0 and a slightly narrower FOV. I am hoping that this will improve light sensitivity and clarity.

The fitting spec is not exactly 1:1 fit. It should be OK, or?

I think it would be ok but I don't know that the Starlight lens would be the best lens for your first project. Every one of us who has experimented with these lenses has found them to a real bear to focus. It can be challenging because these lenses have a very short depth of field and there is very little margin for error. And most of us who worked with these Starlight lenses used ones with an ƒ/1.2 aperture so an ƒ/1.0 aperture would be even more tricky to focus accurately, plus you have to decide carefully about what point (hyperfocal distance) you want to set the initial optimal point of sharp focus at out in front of your vehicle. Typical lenses used in dash cams have a deep depth of field so more or less everything from directly in front of your car out to almost infinity is in focus.

You could try it but just know what you are getting into. Even when you get it in focus the short depth of field can be a trade off in a dash cam. Some Starlight lenses are better than others on this score but the ƒ/1.0 is probably not going to be one of them.

 

[cozzykim]

I think it is quite a good idea, although different people are going to want different amounts of "zoom" to match their car?

What field of view would you want?

I suspect the RTC300 would be rather narrow for your rear use, the field of view must be approximately 1/2.6 of a normal VS1, it is meant as a telephoto, not just a narrow field of view camera.

Having looked at your rear image,

It appears that you want most of that width, it is the height you don't need, so a 21:9 or maybe wider aspect ratio resolution mode would be good, and that can be done via firmware update...

Looks like 21:9 is a new option in the latest firmware, so I'll be trying that.

 

[DCS Australia]

I think it would be ok but I don't know that the Starlight lens would be the best lens for your first project. Every one of us who has experimented with these lenses has found them to a real bear to focus. It can be challenging because these lenses have a very short depth of field and there is very little margin for error. And most of us who worked with these Starlight lenses used ones with an ƒ/1.2 aperture so an ƒ/1.0 aperture would be even more tricky to focus accurately, plus you have to decide carefully about what point (hyperfocal distance) you want to set the initial optimal point of sharp focus at out in front of your vehicle. Typical lenses used in dash cams have a deep depth of field so more or less everything from directly in front of your car out to almost infinity is in focus.

You could try it but just know what you are getting into. Even when you get it in focus the short depth of field can be a trade off in a dash cam. Some Starlight lenses are better than others on this score but the ƒ/1.0 is probably not going to be one of them.

Wow! Your explanation is just second to none. The hyperfocal distance is question I had not taken in mind, but yeah, the current lens merely is focused only on the car directly in front and only optimal when its within 5m.

As you pointed out, the narrow FOV will certainly be an improvement to start off with. Perhaps the 16:9 ratio is also at question. 4:3 seems enough and maybe better.

Overall, I think most dashcams are a marketing gadget. YouTubers influencing Blackvue 970X Plus and Thinkware U3000 without HDR triggered me to think of this idea. I think IMX335 and IMX675s are quite ideal for dashcam recording.

Finding the right lens that can replace the current one seems to be quite a homework too. I'll keep you updated in due course. Thanks mate!

 

[viofo]

It is very hard to find a telephoto lens can fit the VS1, we will check.