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How to make a fish eye lens for a Nikon D-90 Digital SLR for $16

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Picture of How to make a fish eye lens for a Nikon D-90 Digital SLR for $16
I got the inspiration to do this Instructable while reading another Instructable that accomplished the same "fish-eye" effect using a PVC reduction pipe and an entry door viewer.

There was concern in the prior Instructable about around scratching the lens so I wanted to solve that problem in my easy to build fish eye lens as well as make a version which is easy to use, remove, etc.

I decided to modify the design by using an existing camera attachment which would easily mount to the camera and comes with most Nikon lenses.

The secret to my design is to use the lens shield as the attachment platform which allows the fish eye lens to be easily attached and removed from standard lenses while enabling a hands free experience.

The lens that I am using in the shot below is a Nikon 18-105mm VR lens. It came with the kit when I bought my camera.

Step 1: Prepare the materials

Picture of Prepare the materials
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The only thing that I had to buy was the door entry viewer which was $15 and some change so I rounded to $16.

In addition to that you will need:

- 1 Entry Door Viewer - The one shown below is a 160 degree large diameter version.
- 1 scrap particle board. 3" X 3" square
- 1 scrap particle board 1.5" X 1.5" square
- The old handy duct tape approx 10" in length
- Spare Lens shield - I never use one on this lens anyway so I'm using the one that came with it.
 
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shantr0n5 years ago
Love the front door photo :D
Fantastic job! This makes me almost wish I hadn't spend $100+ on my fisheye =x
Where do you get a real fisheye for only $100 ?????????????
you dont with camera lenses you get what you pay for
my_key shantr0n5 years ago
Where can you buy a fisheye for a dslr for only 100+? Where I live it's more like 600+...
for me its 800+... hence my fascination with this 16 dollar instructable.
 Damn, just looking at this instructable makes me shiver. I mean why get a proper camera and then rape it with a crap quality lens? Just save some money, get a job.
I'm curious as to why you are here at all, as your comment can apply to 99% of the instructables here.

the point is it works, and works well. a better question is why spend $600+ when it can be done for $16
'Fraggotmode' has a point. While it's a nifty little trick, it has no control over aperture, no way to focus it, and aberrations ruin the photo...being the owner of both real fisheyes and those inexpensive fisheye converters, I do happen to know what I'm talking about. His comment doesn't apply to 99% of instructables, that's a gross miscalculation.

Why spend $600? Because stopped down to f/4 on my Tokina, I can do 100% crops and still have tons of sharp detail. Try that with this, and tell me how it goes. It CANNOT be done for $16 on the same level as a real fisheye. Don't compare a $300 junker to a Bugatti.
J@50n gwildor4 years ago
 agree!  This can also be done to point and shoots, (my section).
altomic5 years ago
rather than buying a peep hole thing, use a the lenses in the view finder thing from a disposable camera. just turn one of the lenses around and it turns it into a fish eye.
great idea dude ,, tell me exctly how do u turn a l\nikon lens into a fisheye simply by inverting one lens in it
aerika altomic4 years ago
wow! i never knew that! i just tore one apart now, gonna make the cheapest fisheye cam ever! thx! :D
andystorrie4 years ago
 how close does the door view finder have to be to the lens and i seem to have alot of camera glare is their anyway of getting rid of this?? thanks, andy.
Will this work on any other Nikons?
 it will work on ANY camera, just shrink the size of the tube to fit the diameter of your camera barrel! 
Tuqit4 years ago
Agreed that this was more work than was needed. I made one many years ago, long before Instructables was even an idea on the net, using the same peep-hole optics for my very first digital camera. Using just a cap from a butane-refill can as the holder to slide it over the lens barrel. It was just the right diameter to fit the camera's lens housing lightly but snuggly enough to hold it in place. As others have said, it can also be mounted in an inexpensive lens-cap. These work exceptionally well on smaller P&S cameras with a 3X or greater zoom lens on it. As the exit pupil of the peep-hole matches the entrance pupil of the smaller diameter lens on most smaller P&S cameras. You need about at least a 3X zoom to be able to zoom into the smaller circular image in the center of your field of view, getting the full circle to fill the camera's frame from edge to edge--making use of as many pixels as possible for the greatest detail and resolution.

Now here's for the important bit., and why I logged in to leave this comment: The strongly negative lenses in these peep-hole devices, as well as being so inexpensive, are not blackened properly on the edges so you get that light grayish framing around the outside of your images as well as producing much lower contrast and lens flares from bright lights. (This lightness also makes it difficult to mask out later when you want a completely black circular mask for prints or displaying the image.)

Take the front of the peep-hole apart (the front ring unscrews from the main barrel) where the flat lens faces toward your subject. You will find two identical strongly negative lenses there, touching inside-face to inside-face. Use a good black magic-marker or sharpie to completely blacken the sides of the two negative-lens elements (they are both identical so there's no need to keep track of which goes in front or back). Being careful, of course, to not get any magic-marker on the polished faces of the lenses. Try to not get any dust or fingerprints (or magic-marker) on the polished lens areas. If you do, carefully clean those surfaces without destroying your intended blackening job. You might want to take the time to use some flat-black paint or marker to blacken any other internal surfaces in the barrel of the lens-housing. Reassemble. Your images will improve greatly.

If you have a "chromatic aberration" filter in your photo-editing software, you can then use it to remove the small amount of CA that these inexpensive lenses impart in your images. PTLens being a good plugin for this, but there's also some good freeware plugins for freeware editors like Irfanview and FastStone, a free plugin called CAFree by Tom Fiddaman works very well, Google for it.  With these inexpensive lenses and a little editing you can get faux fish-eye images that rival some of the $2500 fish-eye Nikkor lenses for SLRs. I was amazed what kind of image quality could come from such an inexpensive lens design, especially when the lens elements aren't even achromats. This shouldn't be possible, but it is. (For the naysayers, don't knock it till you've tried it and compared the two.)

But be sure to blacken the unpolished areas of those optics inside. You'll be surprised how much the images improve.


 Talk about the hard and expensive way (lens hoods are expensive) to do something simple! Just glue one to the front of a cheap lens cap that can be found on eBay. Us geezers were doing that over 40 years ago. 
quepez4 years ago
la neta que listo e ingenioso carnal
Etitan4 years ago
Quick, he lives at 20711, it's the gray house, let's get him! :)

Anyways, nice instructable, might just have a cheap xmas gift for my friend with photography skills (and as tight a budget as mine)
 Awesome idea!
The crop is pretty bad though...
Maybe if I can find some nice "detective lens" to replace it...
Nice gadget. I'm going to make one for my grand daughter's entry level digital camera. It's not a true fisheye lens because the image doesn't fill the frame, corner-to-corner, but it'll give her a feel for what a fisheye lens can do. On the other hand, I wouldn't use one with my Nikon because it would be like putting dollar store oil in a high performance sports car.:-).
Dollar store oil will destroy a sports car..... this will do absolutely no damage. Give it a whirl ! I've just stuck one on the front of a D700, great fun and no harm done :-0 (and a hell of a lot cheaper than the alternatives)
The dollar store oil in a sports car is a poor analogy. This fisheye on a budget will not damage the camera and this instructable could make for a pretty cool, cheap toy to experiment with.
MjPadfoot5 years ago
wow, awesome instructable! and its an easy DIY too!
kirnex5 years ago
This is conceptually great, but its purpose is a bit antiquated, isn't it? After all, there are a dozen or more programs graphics programs out there that can do this with an ordinary picture via filter. Also, I know I certainly would not duct-tape anything to my D-SLR lenses. However, I think this idea would be very cool to use on a disposable 35mm (of course, you'd need to make some mods). How cool it would be as a project for kids--to teach them about light refraction, distortion, ways to manipulate photos, etc.! I definitely give it tops stars for that purpose. Love your example photos, too.
nothin is taped to the lens it is taped to the lens shield
duh. thanks, captain obvious. don't you wonder why you were the only one caught up on the semantics of my statement?
Kirnex, I see where you're coming from and while this is true with some effects a real fisheye can't be truly mimicked in software. The reason I say this is because the fisheye is intended to get you a very wide field of view, something that has to be done when the picture is being taken. If you're just after the distortion part then yes, the sphererize filter in photoshop can imitate that. Another aspect is how this effect changes the way you shoot, for example the effect produced by a Lensbaby can be mimicked in software however if you've ever shot one you'll know having the effect through the lens will change they way you take the photo and which photos you take. Just my 2¢ For $16 I'm going to give it a whack, probably won't be taping it to any L series lenses though ;)
Very true, I agree that it would definitely effect the way you choose to shoot your picture. I guess my feeling, after having spent 10 years with an antiquated (yet quite expensive) digital camera (and only recently spluring on my newest D-SLR) is that I'm so used to having to make post-processing adjustments via CS4 anyhow, that this clever adaptation would not be practical for me, personally. As I told Banjomaster, though--and I'm sure since we all apparently enjoy photography, I'm probably in good company here--I think this is absolutely fabulous for teaching new photography buffs (and kids, in general) all about lens manipulation, light refraction and it is even more brilliant yet in demonstrating how we can make our own adjustments and contraptions to assist our creativity. I think back to the pioneers of the art and am utterly blown away by some of the inventiveness that got us to this point. I think it must have been minds much like Banjomaster that led us to where we are now in terms of technical ability. I really am grateful for that. Left to my own devices, I'd probably still be using a 110mm disposable. ;-)
Banjomaster (author)  kirnex5 years ago
Thanks Kirnex, I had fun with it and others will too I suspect. :) Reading some of the comments alone was worth the post. :)
Oh, yeah... that's one of the things I love about this site and all the participants. There really is a variety in personalities and lifestyles. You know, I am going to do this for my son this weekend. He is 12 and just getting into photography. He loves to make things, too. This is a project he can really enjoy and be proud of. I think it's great that you shared it with us. Thanks for that!
Banjomaster (author)  kirnex5 years ago
If you flip the smaller square box and put it on the inside, I have found that you get just 1/2" closer to the actual lens thus increasing the size of the image which reduces the amount necessary to crop and you use me of your sensor. Just be careful that the door viewer isn't too long so that it touches your lens. Have fun!
beshur5 years ago
Great idea! )) +1) Optical quality worstens, though
joedude5 years ago
Great idea! Love the fish eye effect! Here's a little idea for those worried about all the cropping required... perhaps you should try shooting in RAW image format. Giving yourself more overall image quality in the final cropped picture! I may give this a shot on my D5000!
Brumzzz5 years ago
It's a good idea, but isn't there a way to get rid of the black circle around your photo? 4/5 =)
noahh Brumzzz5 years ago
you could crop it out in Gimp or pretty easily.
ReCreate noahh5 years ago
Or MSPaint, Much, much Easier, No need to download anything.
Brumzzz noahh5 years ago
Gimp?
GNU Image Manipulation Program ...GIMP!
Banjomaster (author)  matroska5 years ago
Cropping is my method for now. My camera shoots with high enough resolution that a cropped photo is still usable. I may try to see if I can improve the lens coverage some but for me and only $16, it feels sufficient. I used Windows Live Photo Gallery and select the fix menu and use a square crop. Resize the crop and move to the next pic. Automatically it is saved and I'm working on something else.
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