[Nokia Lumia 1020] motoi_bogdan:
ok so i found a pair of used glasses. They have heliomate lenses, ie. they darken by themselves when exposed to sunlight but, i got them for free and figured out it's worth a try.

Also in Romania, you can go to a store specialized in manufacturing seeing glasses and buy lens separately. For example a single -2.5 glass lens will cost about 3 euro here and the polycarbonate ones (needed for this project) about 8-10 euros.

But since i have this glasses i used one of their lenses.

First of all, the lenses are too thick to simply place inside the phone. Therefore some DIY action is required.

Here's what i did:

1. First - removing the original lens over the black cap on the back of the phone. I used hot air, that thing is really stuck in there with some nasty glue stuff. Here's how it looks when removed:

2. I then made a drawing of what i must do with my lens to fit inside the casing.

Click on the image to see the full drawing. The first picture shows the new diy lens as viewed from the top, while the second one shows the profile of the lens. This thing is made using a single lens.

3. I removed one of the glasses lens and started cutting a triangle shape on the center of it. You must use the center portion because the thickness of the lens varies and if it's not constant in the center of your lens you will get a lot of barrel lens distorsion when taking photos. Also, you should use plastic lens, since cutting glass lens is impossible with DIY tools.

I cut the lens using a fine saw using a blade made for cutting metals, or you can use a bread knife, the ones that have jagged blades. It's a slow process, it toked 30 minutes to cut that triangle.

4. Now, I've begun grinding the edges of the triangle with a file, in order to begin forming the upper circle that must be inserted to the back of the phone's camera ring. Here's how it looks after the first try.

5. The hexagon shaped part now must have it's corners grinded. Some care must be taken not to scratch the upper and lower part of the lens. Using a spare casing (silver color one in the photos) i checked to see how much to grind in order to fit the part inside. After all of this is done, here's the end result.

6. I've then inserted the new lens inside my phone casing. A little more grinding is needed to align the lens with the case and the sensor. In order to adjust that - we have those 3 blunt triangle edges. I grinded those to make them sit flush inside the casing with the lens being parallel to the sensor itself.

Once the lens was inside, i temporarely placed the sensor over it and tested how some sample photos look. I took some pictures of far away objects looking for edge to edge sharpness or barrel distorsions. Once I found the optimum position i place a little bit of glue on the edges of the triangle to secure the lens inside.

7. Once that is done, i reassembled the phone. Here how the new lens look, as seen from the back.

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It's a bit yellowish because of that heliomate coating but it doesn't seem to affect the pictures taken.

How this works? Well, i can now focus at things further apart then 2 meters from the camera. I can do landscape photos (that was totally impossible before). Also the new lens doesn't prevent macro focus.

After all of this I've also learned that a -2 lens would have been ideal, because before of this modification i was able to macro focus at about 15-16cm and now i can only focus at about 18-20cm minimum. The lower you go with these lens (-3, -4 etc) the further you increase the minimum focus distance. I don't care much of the lost 2-3cm but if anyone should try this --- try testing with -2 lens first.

Also, some optics stores (in my country at least) can grind the lens for you (i found this ...of course... after i finished all of this) . You give them the old lens you removed and they will measure it and make one from the new lens.

All in all, it took me about 2 hours since the plastic lens are really easy to grind, it's a pretty soft material.

I didn't post photos taken, just imagine a good working sensor, it simply works. They are not that valuable for other people. It's better to make your own tests, at first by just placing a -2 pair of glasses 1cm in front of your camera and try to focus. If it improves your focus, you may want to read this "tutorial" again and maybe give it a go.