Jeff,
Looks very nice. Have you been able to test whether the derlin ring will show up in the corners? Also, did you use AR (Abrasion Resistant) Polycarbonate?
I took my modified version to 82' and it works great. On the R4 setting I still get the oring in the photo, but that beats being blurry.
Here is my latest video from a line freedive:
http://www.youtube.com/watch?v=r6IP2gwqISw
Jeff,
The lense extends about 2mm past the outer edge of the ring where the screw holes are.
Dave
I got mine direct from Gopro since nobody had it in stock. It arrived a few days after I placed the order
Parts list
6x Mach Screw, Stainless, Pan, 0-80 x 3/8 L (5/16L might work better if you find them) I got mine at Ace Hardware for about $1.50. Here is a Grainger link
http://www.grainger.com/Grainger/items/1ZB13?Pid=search
.093 In. x 11 In. X 14 In.Acrylic Sheet 11x14 sheet is $3.50 at home depot
http://www.homedepot.com/h_d1/N-5yc1vZ1xh8/R-100282591/h_d2/ProductDisplay?langId=-1&storeId=10051&catalogId=10053
1- O-ring 4.5x20mm. Mine is Nitrile (N70). I got this at a local shop here that gave me a sample.
6x 2mm thickness washers for the screws since they are a little long. Again 5/16L may work without a spacer washer on the outside of the port.
Cut a disk from the acrylic sheet and drill the 6 holes for the screws. You can use the black ring from the original housing as a guide.
Take off the original lens and gasket. Replace the gasket with the 4.5mm oring and lay the flat port on top and screw down to where the lens of the camera is not compressed by the flat port.
There are variations of this that could probably remove the o-ring from getting in the picture, but this is a robust seal. The only thing you will have to be cautious of is at depth the o-ring may compress and press against the lens. I plan to put some spacers between the port and the housing to keep if from compressing more.
Here are some photos of the latest prototype.
Dave
The o-ring works great at sealing the flat port. Tested it today off the dock to about 30'. This is the r2 setting. With the new o-ring seal there is some minor black corners in the photos and with r4 (960) on the top corners. r2 (720) works great and I think I like this format best for underwater. Here is some video I took off the dock, r2 mode. http://www.youtube.com/watch?v=mbZZuPfMTLk
It is difficult to assess the focus but I will be doing more tests soon.
Yes, the Vignette should go away when I find the right o-ring.
I think this shows that the flat port works great. I am going to go with it. This is the best I have seen in terms of sharpness around the edges. This is more than acceptable when you consider the field of view.
Next I will find the right o-ring and the dunk it to 100' or so.
Dave
I replaced the existing dome port with a flat port and did not have to use any glue. I still need the right O-ring which the guys at www.oringswest.com will have for me when I stop by their office this week. The black corners are from the jury rig seal so I could test it in the water. The lens is just about touching the inside of the port. Here are some photos.
Notice the ruler at the bottom edge of the frames in the last two photos.
Dave
Seattle
Well I don't think a diopter will work. I tried a +4 and it helped but by the looks it may need a +10 to get it in focus.
So now I am trying the flat port. I have taken off the current dome port and have a plexi flat port that I will seal using a thick o-ring that will mate directly to the housing. I will use the same diameter screws in a longer length to secure the port and seal it to the oring. I will let you know how it goes.
The other guys who have flat port mods need to take photos so we can see if there is vignetting. Preferably with a photo subject that will allow us to view the sharpness of the edges of the photo.
Thanks
Dave
I swear by my Elios suits. I use my 6mm, medium density Heiwa, open cell inside, smooth skin outside all year round. When your diving in 45 degree water you need to learn the details of suits fast. I use high waist pants for a couple of reasons.
I also swear by my Marc Valentin 75cm. It is super accurate for me. And not too big to lug around on a kayak or boat. 70cm is the optimal size gun for this area.
Adrian,
I want to spear a halibut, that is why I am training with line diving to 120'. We are going to try this summer hopefully off freshwater bay bouncing to 80' or so. We have a gun guru who will put together a halibut gun when we are ready.
Get a suit and your welcome to join us anytime. We have a yahoo group.
http://groups.yahoo.com/group/Bottomsounders/
Dave
I spent almost 10 years in the Keys. I miss the warm water but I love diving in Puget sound. You gotta have a good wetsuit though. Thanks for the welcome.
Dave
PS the spearing at Neah Bay was great. Lots of fish.... It is pretty remote.
I was thinking of removing the current housing lens which is actually glass. Using a spacer ring to mount a flat lens just in front of the cameral lens. So it would go like this. Seal-spacer-seal-flat port. All screwed onto the housing using longer screws.
I also have another potential fix which does not require housing mods. We'll see...
I live near Seattle and freedive all around Puget Sound. I have a boat and I also do photography. My most recent trip was out to the Cape Flattery area for some great spearfishing. I just purchased a Gopro video and would like to use it freediving once there is a solution to the underwater distortion.
Dave
www.underseaimages.com/blog
