Blurfix vignetting with alternate filters?

[spoolin01]

I just got a reply from Snake River Prototyping (the Blurfix makers) that using filters that haven't been ground down - I was thinking about the possibility of stacking a red filter over a clear one for U/W swapability - will increase vignetting. Apparently their system is right at the limit of vignetting (in the wider angle modes), and just the extra millimeter or two of rim extension, if the outside threads aren't ground down, is enough to increase vignetting. I'm wondering if anyone recording at 720p and using other than OEM filters has seen this?

 

[Marty Cerven]

Unfortunatly with the gopro being as wide angled as it is and with the power button's location fixes like the blurfix are limited to a maximum size as they are now, otherwise they would block the power button.

This is why they are so close to the limit and you wont get away with any filters that arent very low profile in the wide angled modes. This also means stacking wont work unless you just had another filter without frame you could put inside the frame of the clear filter or a larger frame that didnt get in the way.

I only use the filters provided by SRP but I did get a very low profile cheap cp filter which worked ok just had a hint of vignette in 720p but it wasnt a great filter as it made it much darker then the marumi cp filter i use now.

It would be good if people could post any filters theyve found that work well with the blurfix.

 

[AquaProHd]

Hey Spoolin1 - Just a quick thought... Remember to consider pressure testing when looking for an alternate filter solution. Have a great day!

 

[spoolin01]

Hey Spoolin1 - Just a quick thought... Remember to consider pressure testing when looking for an alternate filter solution. Have a great day!

That's a good point. I saw the pics in the other thread. I have a pressure pot I can use if I go this route.

 

[joecwazy]

So filters not ground down by SRP will experience vignetting in 170 wide modes?

 

[ronscuba]

Why use a clear filter UW and not just the red filter ?

What is the pressure test for filters ? Why do you need to pressure test ?

 

[Dauntless]

Why use a clear filter UW and not just the red filter ?

What is the pressure test for filters ? Why do you need to pressure test ?

Because pressure presses the glass against the "O"ring, making a tight seal but some glass filters did break in SNP research. Also avoid the bigger desiccant balls in the lollipop grove for the same reason, the glass will press against them and create trash within the area behind the front filter. SNP has a list of filters that passed the pressure test but I would take my case with filters assembled down to my local dive shop(without camera inside) and have them pressure test it to ~ 130' or deeper if you are planning a deeper dive.

 

[ronscuba]

Because pressure presses the glass against the "O"ring, making a tight seal but some glass filters did break in SNP research. Also avoid the bigger desiccant balls in the lollipop grove for the same reason, the glass will press against them and create trash within the area behind the front filter. SNP has a list of filters that passed the pressure test but I would take my case with filters assembled down to my local dive shop(without camera inside) and have them pressure test it to ~ 130' or deeper if you are planning a deeper dive.

Your filter seals against the external port ? Sorry if this sounds like a stupid question. I am just used to internal filters and external filters that allow a layer of water in between the filter and port.

 

[spoolin01]

Your filter seals against the external port ? Sorry if this sounds like a stupid question. I am just used to internal filters and external filters that allow a layer of water in between the filter and port.

In this case, for optical reasons as I understand, the external filter on the add-on port seals as well, creating a void between the intrinsic case dome port and the external filter. This is how the UW blur of the original GoPro case is fixed (BlurFix, tada!), without replacing the original dome port with a flat one - another solution to the problem, but one which suffers from vignetting in the wide angle recording modes. Apparently the BlurFix approach is able to reduce vignetting to nearly nothing if low-profile external filters are used, ones which have no external threads for stacking of additional filters. The ability to add and remove color correction filters UW, has frustrated users of the various UW fixes, so far.

 

[ronscuba]

In this case, for optical reasons as I understand, the external filter on the add-on port seals as well, creating a void between the intrinsic case dome port and the external filter. This is how the UW blur of the original GoPro case is fixed (BlurFix, tada!), without replacing the original dome port with a flat one - another solution to the problem, but one which suffers from vignetting in the wide angle recording modes. Apparently the BlurFix approach is able to reduce vignetting to nearly nothing if low-profile external filters are used, ones which have no external threads for stacking of additional filters. The ability to add and remove color correction filters UW, has frustrated users of the various UW fixes, so far.

I wonder if anyone has investigated using/modifying/creating something like what Ikelite does. A URpro filter with a rubber outer ring which slips over the external port. Then again this vignette issue can easily be eliminated in editing. But I understand many GoPro users don't edit their videos.