[mtmgiants]

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Im just going to give you a little background for what I am looking for and then hopefully I can get some positive feedback. So I have been wanting to get into photography for a long time but as a college student didnt really have the right funds. I played around with a k1000 for the past year to understand how everything really works and how adjusting things affects the pictures. I finally caved this year and bought a K10d. I have taken a few pictures with it but have been busy with schoolwork. The reason i bought the K10d was the price was right and most importantly, as an avid snowboarder I like that it is weather sealed. I have a manual focus 50mm and 28mm lens that I used with my K1000. I am getting a 18-55 WR lens for my birthday in November and cant wait. Ok so to the point... I dont have enough money to get a true 10-17mm fisheye lens but love the fisheye effect commonly seen in action sports pictures and videos. I fond these adapters on B&H and want to know if anyone has some input. What i have read is that you have to stop down your aperture a lot when using the attachments and my concern is that by doing so i will need to use a slower shutter speed and then my pictures will be blurry. Im basically just asking for anyone's advice or personal experience with anything like this. Looking to spend $75. Thanks for the help

Auxiliary (Add-On) Lenses

[Lowell Goudge]

The big attraction is they go on the front of an existing lens so your kit lens if you have one becomes a ultra wide or fisheye lens. In addition since this lens shortens the focal length but does not change the aperture the lens actually gets faster, but these lenses are terrible for latteral CA much of this can be fixed with the pentax photo lab but this is not as good as a true lens obviously

[Adam]

AFAIK you're not going to get very far with an attachment lens- I would try for something like the Zenitar 16mm F2.8 instead. Not the sharpest lens out there, but it gives you a lot of bang for your buck.

[SpecialK]

These are generally, how can I say this...crap as far as optics go. They make excellent paperweights, however.

I had some Canon ones for a P&S that were marginal, but Bower/Opteka was just bad.

I would go for a (manual focus) Zenitar 16 that can be found in the marketplace from time to time for under $200. It has decent performance, is a little fisheye (more so on film).

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Last edited by SpecialK; 11-11-2011 at 10:10 PM.

[bimjo]

Well, in all honesty the DA 10-17 is a CA monster as well, so that's not necessarily a knock on the add-on fisheye. Horrible image quality on the other hand is pretty much a deal killer.

I'd go with everybody else- inexpensive fisheye go for a Zenitar. Not as fishy as the DA, but the pics are good. Or at least more gooder than an add-on.

[RioRico]

This question pops up every now and then.

The short answer: They suck.

The long answer: They aren't too bad for video because moving imaged distract our eyes from how bad they are. But for still images, they suck. I have one of the best-of-breed, a big Kenko 180 Degree adapter. Stopped down to f/22 or beyond, it doesn't suck too bad, but it still sucks. The problem isn't just CA, but great loss of resolution and sharpness around the edges. If you want sucky images, like for posterizations or solarizations or other torture, that's up to you.

Oh, did I mention that they suck? It's true.

My suggestion: If you want a cheap adapter so you can play with fishiness, look for a used one on eBay. Don't go over US$20. Better yet, save your money. Get a free copy of AutoStitch. Shoot some 180-degree coverage and stitch them together into a matrix. Then use the Fisheye tool in some image editor to distort it to fisheye shape. Save your money for some good glass. The DA10-17 is the lens that drove me to Pentax. The Zenitar 16/2.8 is lots of fun and can be had for around US$200, but it's not really fishy. Real fishiness isn't cheap. Oh bother.

[crewl1]

Hey mtmgiants - I have this wide angle adapter laying around I can send you.
It looks like this http://www.ebay.com/itm/Wide-Angle-MACRO-Auxiliary-lens-Nikon-D5100-18-55mm-...item2315f24c06

When I put it on a manual 28mm lens it will go from this



To this



Save the $75 in the kitty for a real fisheye and play with this for the meantime, and when you are done with it gift it to someone else.

If you want it send me your info via PM. Out of town at the moment but can maybe get it in the post by Monday if you can wait.
Larry

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Last edited by crewl1; 11-09-2011 at 08:49 PM.

[mtmgiants]

Thanks everyone for all of the feedback, i guess i will save up some money to buy an actual fisheye lens and not just an attachment. It seems like it is worth is. And Larry thanks so much i will definitely send you a PM. Being new to photography its nice to know there are so many people out there willing to help out. thanks again

[Lowell Goudge]

mtmgiants & crewl1

take a look in the processing forum on a thread I started with respect to lens corrections and lateral CA. ALthough not high resolution I can see lateral CA in Lary's photos, and this can largely be corrected in pentax's photo lab.

What is important with respect to these adaptors and the CA correction and this is highlighted in my thread on CA processing, is that pentax photo lab, and some other programs do Lateral CA correction by rescaling the individual color layers, (i.e. slight change in magnification of each layer with respect to the others) to reallign the 3 layers at the edge of the image. This approach retains the initial sharpness present in each layer and results in a significant increase in edge sharpness, when compared to other CA removal tools that work primairly on fringe removal.

You can also use the distortion correction to de-fish the image to a large extent, although this is not always 100% successful due to the presence of mustache distortion which can result in relitively streight lines in the central 80% of the frame and then drooping / converging lines at the corners, or if you attempt to correct furhter, wavy lines (hence the name for the distortion)

I believe adobe with a properly created lens profile can remove this as well as the lateral CA

This is not to say that this front screw on adaptor is great, but given the right image processing tools, they can produce much better images, at the expense of a little PP time

[Lowell Goudge]

when I get the time, maybe this weekend, I will try to do a shot to illustrate the improvement in sharpness that can be achieved by using lateral CA correction, It will suprose some.

This type of correction has me thinking about photoshop, and adobe lens profiles/

[DaveHolmes]

They do suck... However... They are good fun...
I have one that fits onto my kit lens (18-55) and the only time I use the kit lens these days is when I want to use the fisheye adapter... If you shoot at f11 and are happy to crop the crap out of your shots you can get some quite useable images...
They do suck... So if going for IQ (in the traditional sense) forget it... If you wanna play around and get creative and bendy, they're a dirt cheap way of doing it... For a while...

A shooting buddy of mine uses a Samyang 8mm fisheye lens (nikon mount) which is much (MUCH) better... It comes in a Pentax mount too (sometimes sold as 'Falcon' rather than Samyang) and is considerably cheaper than the Zenitar 16mm (at least here in the UK) if you want another option...

Chances are, you'll get it, use it for a week or so and then realise that fisheye isn't as cool as you thought it was anyway...

[crewl1]

The Samyang 8mm is a great lens as evidenced by the photos in this thread https://www.pentaxforums.com/forums/lens-clubs/33549-fisheye-fever-club-flaun...photos-69.html

[RioRico]

They do suck... However... They are good fun...

The adapters are fun as long as you don't expect anything really *photographic* from them. Treat the output as raw material --shoop the sh!t out of those images -- make posters, matrices, animated GIFs, etc -- know their limitations.

Different types of fisheyes exist. All the cheap adapters AFAIK and the somewhat affordable lenses are frame-filling fisheyes, using various projections. Some of the exotic adapters and not-so-affordable lenses are full-circle fisheyes. The Kenko 180 Degree fisheye adapter is like that. I mount it on a medium zoom on my K20D. At 40mm and shorter, it's full-circle. From 60mm and longer, it's frame-filling. It's fun to play with fishy projections, changing the distorions.

It comes in a Pentax mount too (sometimes sold as 'Falcon' rather than Samyang) and is considerably cheaper than the Zenitar 16mm (at least here in the UK)

I see it going for US$300-400 stateside, vs about US$200 for the Zenitar. The Zen isn't nearly as fishy. They're not really in the same league, being roughly like the extremes of the DA10-17 range.

Chances are, you'll get it, use it for a week or so and then realise that fisheye isn't as cool as you thought it was anyway...

Yes, there's this problem. Extreme fisheyes have limited application. Crappy fisheyes... well, they have their own uses. Keep the image display size small and the crappiness isn't so noticeable. Just don't look too close.

[newarts]

Would it work to get a good rectilinear wide angle lens then use software to fish-ify the image?

[RioRico]

Im just going to give you a little background for what I am looking for and then hopefully I can get some positive feedback. ... I finally caved this year and bought a K10d. ... I dont have enough money to get a true 10-17mm fisheye lens but love the fisheye effect commonly seen in action sports pictures and videos.

Would it work to get a good rectilinear wide angle lens then use software to fish-ify the image?

OP seems to want to shoot action, so my suggestion of stitching together an image matrix and then fishifying it probably won't fly. Or swim. A good wide rectilinear will likely cost as much as or more than a decent fisheye, and must be wider than 12mm to match the Zenitar 16/2.8, which defishes to 12mm.

If the goal were to shoot video, a cheap adapter would suffice, but the K10D doesn't shoot video, so that's out. Or does the K10D have anything like the 1.6mpx 23fps burst mode my K20D has? Print those 1536x1024px frames small enough and the optical problems won't be real noticeable.

Another option as yet unmentioned is the (Sigma-made?) 12mm f/8 fisheye lens, variously badged as Vemar, Spiratone, Accura, many other names. It is full-circle (2-piece hood) or almost-full-circle (no hood) fishy on full-frame, very-fishy frame-filling on half-frame / APS-C. At about US$100 it's way cheaper than any other superwide lens and not much more than the best(?) 180 degree adapters. It's on T2-mount so any version can easily be put on a Pentax cam. Here is the canonical article on this lens: The Strange Case of the 12mm Fisheye. Look for a copy with the two-piece lens hood.