Here's the set-up:
I thought that Sugru might be the ideal way of fixing the filter mount to the spare back cover, although there was a question of whether it would adhere to the 808’s polycarbonate material. I figured if I didn’t stick then it would at least have been moulded to the right shape and I could superglue it to the cover afterwards.
I started by taking the cover off the 808, inserted a layer of clingfilm over the whole back including the camera hump, and then put the cover which I was modifying on over the top of the clingfilm:
Sugru doesn’t stick to clingfilm, so this allowed me to fix the filter mount to the replacement cover without sticking anything to the camera hump. I then fixed the filter mount in place and trimmed the Sugru to fit. At the moment I am waiting for the Sugru to cure, which takes 24 hours. Here are some photos of the modified back cover:
A day later, Al had the set-up finalised, resulting in:
After 24 hours the Sugru had cured, and it definitely sticks fine to the polycarbonate back cover of the 808. Here is a picture of the modified cover attached to my white 808:
And here it is with a lens cap, providing adequate mechanical protection for the lens but probably reducing the sound from the rear loudspeaker somewhat:
...Next up was the original reason I wanted a filter mount - using neutral density filters to take long exposure shots in the daytime. The 808 will extend its shutter speed up to 2.7 seconds if you force it to. I used my basic flexible arm tripod with a 4th Design tripod mount which I have also modified with Sugru to make it more suitable for the 808. See here for a picture of my modified mount. Here is the 808 with the filter mount and two ND filters attached to the tripod:
Anyway, I headed out and looked for some running water, settling on a footpath near a local weir. It was a dull cloudy day so the light wasn’t very exciting, but I carried on regardless. For those who are interested, I used the following settings in creative mode on the 808: 8MP PureView, 16:9, Superfine, Vivid, Self-timer 2s, Flash off, ISO 50, ND on, Hyperfocal. All other settings on default. On the mount I had one ND8 neutral density filter and one variable ND2-ND400 filter, set at the minimum. I have no idea what ND2 and ND8 combine to give, but I like having the variable ND filter because it allows me to make quick adjustments to the amount of light available in order to get the desired long exposure.
Here is a 640x360 version of the photo I took, slightly post-processed for contrast:
You can see the smoothness of the water caused by the long exposure in this 100% crop:
A month or two later, Al had had plenty of time to experiment further, using 'reversed' lenses mounted on his filter system:
Using a filter reversing ring I was then able to attach a Minolta MD Rokkor-X 45mm pancake lens which I picked up from eBay, giving me a fairly powerful macro setup.
Here is the setup in action, on a dolly with universal tripod arm:
Because of the way I mount the lens, the image appears inside a circle surrounded by black, even with the 808 on full zoom and the aperture fully open on the reversed lens. Usually I just crop out the detail so that you see a photo in a rectangle, but I’ve left them in for this article so you can see the effect. Here’s one to get you started:
(if you want bigger versions, they are all in this flickr set)
You’ll notice that the depth of field is very shallow. This is normal for any close-up macro shot and it does mean you need to think carefully about what you are taking photos of, as anything not in the narrow focus band will be blurred. At least you get nice bokeh on the 808!
Great experimentation and some lovely photos. All of the above can be found on Al's blog.
Of course, transforming a Nokia 808 in this way makes you wonder why a DSLR wasn't used in the first place, but don't let common sense get in the way of a great smartphone hack!