Backscatter sharp wide lens (uwl-03) doesn't cover the full gopro sensor

[Robin.snapshots]

I just received my backscatter Sharp wide lens (aoi uwl-03) and noticed that the image corners are completely black when using it.  It's not some slight vignetting but the camera seeing the inside of the lens.
 

It seems the backscatter bayonet mount does not get the lens close enough to the port glass to cover the entire sensor. The backscatter bayonet system has some extra space built in it for allowing filters inbetween the port an lens.  

 

The AOI bayonet system doesn't have the filter option. Does anyone here know if that one places the lens in a better position ?

[Davide DB]

Hummmm...

I've used it several times. Just read the other thread here.

Are you checking it in water? On land there's a strong vignette which disappears underwater.

[Robin.snapshots]

6 minutes ago, Davide DB said:

Hummmm...

I've used it several times. Just read the other thread here.

Are you checking it in water? On land there's a strong vignette which disappears underwater.

I remember you using it without the underwater case from the other thread, is that correct? In that case the wet lens might be a lot closer.

 

Here is a quick underwater picture of my sink. There is some vignette but it seems I am looking at the inside of the lens here.

[Davide DB]

Hi Robin,

 

Yes I used it with a 52mm screw mount but I tested the default bayonet mount without problems.

The bayonet mount needs water inside to remove the vignette.

 

 

 

[Davide DB]

 

I used to submerge the gopro on and videos would start with vignetting that would disappear as if by magic as the water entered the wet mount.

 

 

[Robin.snapshots]

17 minutes ago, Davide DB said:

 

I used to submerge the gopro on and videos would start with vignetting that would disappear as if by magic as the water entered the wet mount.

 

 

I Attached the lens underwater so I am sure there is water inside the mount. I also don't see how the mount itself could be installed incorrectly. 

I do get a full projection if I remove the bayonet holder and manually hold the lens in front of the case. So I am wondering now if the AOI bayonet holder gets the lens closer to the case. 

[Davide DB]

Are you setting the gopro lens linear or wide (not superwide)?

 

Sorry I can't help you right now. The lens was lent to me by the official dealer and I returned it. Other people who tried it before me also had no problems.

[ChipBPhoto]

2 hours ago, Davide DB said:

Are you setting the gopro lens linear or wide (not superwide)?

@Robin.snapshots This is my question as well.  I use this wet lens with my GoPro in a GoPro housing with the Wide lens setting.  I do not have the vignette.  

Edited April 2 by ChipBPhoto

[Nikolausz]

I have only vignetting when I use superwide or full sensor readout.

[Robin.snapshots]

19 minutes ago, ChipBPhoto said:

@Robin.snapshots This is my question as well.  I use this wet lens with my GoPro in a GoPro housing with the Wide lens setting.  I do not have the vignette.  

I have the gopro set to RAW shooting so there is only the wide option available.  For video the vignetting is less apparent  but still present in the wide setting.  The circle "moves around" so to speak due to the image stabilisation. 

[Robin.snapshots]

The bayonet converter is mounted flush like this so I don’t see anything wrong with that either. 
 

[ChipBPhoto]

Sounds like a call or message to Backscatter would be the best.  It’s a head scratcher. 

Edited April 2 by ChipBPhoto

[Davide DB]

1 hour ago, Robin.snapshots said:

I have the gopro set to RAW shooting so there is only the wide option available.  For video the vignetting is less apparent  but still present in the wide setting.  The circle "moves around" so to speak due to the image stabilisation. 

 

Try to change the stabilization and see if something change. I've never used warp or whatever it's called

[Robin.snapshots]

On 4/2/2024 at 7:02 PM, Davide DB said:

 

Try to change the stabilization and see if something change. I've never used warp or whatever it's called

Just tried disabling the stabilisation. It does exactly as expected. The black corners are still there only now with the image circle nicely centered.

[Davide DB]

11 hours ago, Robin.snapshots said:

Just tried disabling the stabilisation. It does exactly as expected. The black corners are still there only now with the image circle nicely centered.

 

Really I don't know what's going on.

Last resort, as @ChipBPhoto wrote: contact Backscatter... and let us know.

[Davide DB]

Hi Robin,

 

Any update?

Did you solve the issue withe the lens?

 

Thanks

 

[Elvandar]

The vignetting is normal if you use the full sensor 8:7 format
To avoid it, you need to use a different format, the inon lens that is basically identical got the same issue, to reduce it a bit, you could bump up the stabilization setting, as the stabilization crop more the image.

I'll paste here the recommended setting from the inon website, give it a try:

[turandot]

Hi Robin, Did you solve the issue with the lens @Robin.snapshots? Does it have vignetting or not? I am interested in buying this model, but I'm worried that it has vignetting. Thanks.

[Davide DB]

It's one of the most sold wa lens for Gopro. Plenty of underwater videos with standard housing.

I was curious what was causing his problem as well.

Most probable culprit, a wrong combination of FOV, frame size and IBIS. AOI and Backscatter doesn't give any hint/instructions in the box.

 

[Robin.snapshots]

On 5/29/2024 at 6:07 PM, Elvandar said:

The vignetting is normal if you use the full sensor 8:7 format
To avoid it, you need to use a different format, the inon lens that is basically identical got the same issue, to reduce it a bit, you could bump up the stabilization setting, as the stabilization crop more the image.

I'll paste here the recommended setting from the inon website, give it a try:

Yes the vignetting is always there in 8:7 format.  Backscatters response was to crop the image to 16:9 where it works just fine. 
I find it a bit misleading for a lens to be advertised as "sharp corner to corner" and then having to crop the corners off. 

 

In the meantime, I have tried a friends AOI mount which does sit closer to the port than the backscatter mount. The vignetting with the AOI is considerably less but still present. 

[turandot]

1 hour ago, Robin.snapshots said:

In the meantime, I have tried a friends AOI mount which does sit closer to the port than the backscatter mount. The vignetting with the AOI is considerably less but still present. 

This makes sense, the Backscatter mount has more space between the front of the housing and the wide-angle lens for the color filter. The AOI mount should be closer to the front of the underwater gopro case.

 

Regarding the response of Backscatter in the 16:9 format, it makes sense, this format has the corners cropped compared to the 8:7 format (see attached image)

 

Edited June 4 by turandot

[Nikolausz]

I think the company suggest wide instead of super wide that is still cropped compared to 8:9 format, which is full sensor readout. I'm not surprised that you have vignetting. I also have vignetting at this setup. Just crop your picture

[Robin.snapshots]

When shooting RAW there is only wide mode (full sensor) available and as such I haven’t shot anything else than wide mode (photo and video) which was the recommended setting.  Cropping will yield perfectly usable pictures but is an extra editing step and throws away resolution. This is fine for most users as they will probably use 16:9 or 9:16 which both work well.
The lens is still a great product at a good price point and can be very small because of this limitation. 

 

The issue I have is with the lack of transparency and false advertising.   The lens is sold with the claim of  “Razor Sharp Focus From Corner To Corner" which is simply not true. 
 

 

The reason I started this thread is that I wanted to know wether there was a difference in mounting options. I had hoped the vignetting to go away with a better fitting mount.

[Davide DB]

Besides from the mounting (I used a DIY screw mount) I only used it in video 16:9 so I didn't notice these caveats.

 

[turandot]

@Robin.snapshots To confirm..... vignetting does not appear in the 16:9 format with the Backscatter sharp wide lens (uwl-03)? It is important to leave no doubts about this topic for future buyers... as is my case.

Edited June 6 by turandot