Due to a bad sctratch on one of my Hero4s I obtained a replacement lens from China. The lens replacement was pretty easy apart from the small connectors inside.

However, when I popped the outer lens ring off the appeared to be a small rubber gasket under it. The gasket was damaged and is therefor non-re-useable. Its the gasket in the top right corner of the attached photo. I found a replacement on ebay but wonder what the purpose of this part is. And if its really necessary to be in place.

Wow, that's interesting, would be interesting to see from GoPro. They need to up their game.

I wouldn't be surprised if DJI is going to move the actioncam marked, they have some really nice cameras with little distortion. I think the purchased of Hasselblad makes it even more likely that we can expect a lot from DJI.

Conserning my questions on GoPro downscale, does confirming with standard resolution like 1440p really outweigh benefits of the more custom size downscales like 1500p. This would be the downscale of a 4000x3000 sensor to 2000x1500, which to me makes a lot more sense.

Why do we need GoPro if the smartphone can do the same. :-p

They really need OIS as well.

This one? 1000 FPS! ;-)

http://image-sensors-world.blogspot.no/2017/02/sony-presents-3-layer-stacked-sensor.html

It makes sense since GoPro really needs to up the ante with the Hero6 to be competetive. The chinese has the same Ambarella and IMX117/337 for half the price point (or less) of GoPro.

I also wonder if GoPro can put in an OIS - Optical Image Stabilizer in the current form factor body?

Apparently Ambarella have lost GoPro as a customer for the Hero6.

"The company also disclosed that GoPro, which has been a big customer, has probably dropped it as a supplier for future products. That loss triggered a flurry of changes to analyst models, including at least one upgrade and more than one cut to price targets.

The general consensus toward GoPro in this case seems to be: “Don’t let the door hit you on the way out.” However, there’s no 100% guarantee that the company’s business is gone, as Ambarella management simply said they’re very confident that their chips aren’t in the Hero 6 camera due to a lack of design activity."

I have previously read rumors about the use of a Samsung processor in the Hero6.

I am also trying to understand how the different crop modes are created?

The IMX117 sensor i natively 4000x3000 and the 4K video is 3840x2160. 1080p is just a 2 times downscale of 4K, which makes sense.

What I do not really understand is 2.7K, which is 4K video downscaled to 2704x1520. This is 1.420118343195266 downscale, which to me seems like a horrible downscale factor, 1.5 I could understand. 2.7K 4:3 uses the whole sensor, which is a crop of 1.479289940828402 and also a mess.

Does this not make 2.7K inherently useless, worse than 1080p? 2.7K medium uses pixels one to one, which is clean.

1080p medium is just the 2.7K medium downscaled, which is a 1.408333333333333 downscale. Again not very clean. 1080p narrow is one to one, which is good.

Some digging around tonight:

The Sony IMX117 was release in 2012 and made it into the Hero3. This sensor allready accomodated full 4K at 30 fps. But this was not fully exploited until the Hero4 with Amabrella A9 soc. Previous 4K limitations because of the A7 SOC.

The upgraded sensor - the Sony IMX377 was not out until 2016. I'm not sure about the availability date for large quantities, but it did not make it to the Hero5. The IMX377 does 4K at 60 FPS, 1080p at 120 FPS and 720p at 300 FPS. Also the Ambarella A9 soc is only 4K 30 FPS capable. So new camera need both.

My guess is that there will be a Hero6 in 2017 with the IMX377 and the fastest Ambarella 4K/60FPS SOC chip A2 or A22 which also includes HEVC support.

If anyone have a pointer to the Ambarella SOC in the Hero3+ give a reply!

Thanks, super valuable information :-)

I vaguely remember something about a change from 3 to 3+. The optics have remained the same since 3+, right?

Hero3 and Hero3+ have different lenses as far as I have been able to uncover.

The sensors have been Exmor from Sony.

The SOC has been variations from Ambarella.