Fisheye adapter - who's used one?

Michael Piziak · 02-05-2023, 10:15 PM

Staff note: This post may contain affiliate links, which means Pentax Forums may earn a small commission if a visitor clicks through and makes a purchase. If you would like to support the forum directly, you may also make a donation here.

As they say, you learn something every day.
I was simply window shopping on the auction site at Fish Eye lens for Pentax & came across a Fish Eye adapter.

Anyone ever used one? Which focal length lens would be optimum to try one with - maybe a nifty fifty ?

Addendum: Here's one on this site: https://www.pentaxforums.com/userreviews/opteka-02x-fisheye-adapter.html

As expensive as fish eye lens are & as little as people use them, one of these adapters may be worth it, eh?

Addendum: How do these adapters attach. Do any attach simply by k mount to the lens? I see some say 55mm and so forth (wouldn't a lens have to be reversed?)....

Addendum 2: Here's another one on the auction site - does this one attach via reversing a lens to attach to it??? https://www.ebay.com/itm/193175975392?hash=item2cfa2f75e0:g:ssAAAOSwD21jas-5...Bk9SR8jG79LEYQ

Last edited by Michael Piziak; 02-05-2023 at 11:07 PM.

MarkJerling · 02-05-2023, 11:50 PM

They screw into the filter thread. Usually, the quality is marginal.

**yucatanPentax** · 02-05-2023, 11:55 PM

Fisheye adapters, usually, attach by screwing into the filter threads of the lens. So, if one says 55mm, it will screw into a lens with a 55mm filter thread or any lens with a smaller thread, using step-up rings.

Using step-down rings from a larger filter thread size will often result in reducing the size of the image, like vignetting but possibly more severe, depending on the differential.

They're generally lower image quality as not a lot of investment went into them. "Tele" and "wide" adapters were also made, aiming at keeping the regular lens on the camera and just adding an "adapter" in front. As the optics weren't well matched and were inexpensively created, they were only moderately successful. It was just as easy to change the lens out completely and have an intentionally created "wide-angle" from scratch. The advantage of all these adapters was that they could be put on the front of any lens of any brand, only needing the right size or step-up rings, to be successful, not different lens mounts.

If you find one very inexpensively, it may be worth experimenting to see what you think. You might need a step-up ring or two to fit your chosen lens. They were originally intended to be used on roughly "normal" lenses, like around 50mm focal length or thereabouts.

**ramseybuckeye** · 02-06-2023, 06:23 AM

Might be an ok fun thing to experiment with if it’s cheap enough. I’m sure it will reduce image quality, but a good way to decide if you want a fisheye lens. I had a fish eye once and tired of it pretty quickly, though some people love them.

35mmfilmfan · 02-06-2023, 07:30 AM

I've used one on a Pentax-M 28mm lens - as others say, fun to play with. if you actually want to obtain consistent results, a tripod and spirit level are worth considering, to avoid unintentionally wonky horizons. I think you might run into major focusing difficulties trying to mount it on a reversed lens, though I have no doubt an adapter could be constructed to make this possible - which would probably cost more than the fish-eye adapter !

**MJL** · 02-06-2023, 08:21 AM

These lens front gizmos work best with 50mm lenses, although Lens Baby even made one for GoPro. Attached is the one on GoPro.

I tried different one on different lenses throughout the years and as ramseybuckeye pointed out - they are fun but the novelty vaporized within days even with a real fisheye lens.

Thagomizer · 02-06-2023, 10:43 AM

I picked up a "Semi Fish Eye" to play with. I'm not where it is right now, and I don't recall the brand. On APSC I'm just losing the corners with a 35mm lens. Here's the original shot:

...and the cropped version:

Ready to Explode

I haven't used it much since my initial test drive, but It's pretty fun. You want to be careful that you don't overuse it, but with careful handling and the right subjects, it can provide striking results for not a lot ogf outlay. As I'm not ready to get an actual dedicated fish-eye lens, this will do for now.

02-05-2023, 10:15 PM	#1
Michael Piziak Closed Account Join Date: Dec 2013 Location: West Virginia Posts: 2,815	Fisheye adapter - who's used one? Staff note: This post may contain affiliate links, which means Pentax Forums may earn a small commission if a visitor clicks through and makes a purchase. If you would like to support the forum directly, you may also make a donation here. As they say, you learn something every day. I was simply window shopping on the auction site at Fish Eye lens for Pentax & came across a Fish Eye adapter. Anyone ever used one? Which focal length lens would be optimum to try one with - maybe a nifty fifty ? Addendum: Here's one on this site: https://www.pentaxforums.com/userreviews/opteka-02x-fisheye-adapter.html As expensive as fish eye lens are & as little as people use them, one of these adapters may be worth it, eh? Addendum: How do these adapters attach. Do any attach simply by k mount to the lens? I see some say 55mm and so forth (wouldn't a lens have to be reversed?).... Addendum 2: Here's another one on the auction site - does this one attach via reversing a lens to attach to it??? https://www.ebay.com/itm/193175975392?hash=item2cfa2f75e0:g:ssAAAOSwD21jas-5...Bk9SR8jG79LEYQ Last edited by Michael Piziak; 02-05-2023 at 11:07 PM.

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
SMC Takumar 17mm fisheye VS Minolta Rokkor 16mm fisheye lens	kmcsmart	Pentax SLR Lens Discussion	18	10-28-2021 04:58 PM
Pentax Ua-1 adapter: is any one familiar with one, can it be used with the K 01 ?	aslyfox	Pentax Camera and Field Accessories	6	09-08-2019 11:41 AM
Pentax hot shoe adapter + off shoe adapter - any limits on the flashes used?	MSL	Flashes, Lighting, and Studio	4	10-25-2014 06:13 AM
Opteka Fisheye Adapter vs. Opteka 6.5mm fisheye	goldenarrow	Ask B&H Photo!	2	08-11-2010 04:04 PM

02-05-2023, 11:50 PM	#2
MarkJerling Moderator Site Supporter Join Date: May 2012 Location: Wairarapa, New Zealand Photos: Gallery \| Albums Posts: 20,421	They screw into the filter thread. Usually, the quality is marginal.

02-05-2023, 11:55 PM	#3
yucatanPentax Loyal Site Supporter Join Date: Dec 2009 Location: Dallas / Yucatan Posts: 1,841	Fisheye adapters, usually, attach by screwing into the filter threads of the lens. So, if one says 55mm, it will screw into a lens with a 55mm filter thread or any lens with a smaller thread, using step-up rings. Using step-down rings from a larger filter thread size will often result in reducing the size of the image, like vignetting but possibly more severe, depending on the differential. They're generally lower image quality as not a lot of investment went into them. "Tele" and "wide" adapters were also made, aiming at keeping the regular lens on the camera and just adding an "adapter" in front. As the optics weren't well matched and were inexpensively created, they were only moderately successful. It was just as easy to change the lens out completely and have an intentionally created "wide-angle" from scratch. The advantage of all these adapters was that they could be put on the front of any lens of any brand, only needing the right size or step-up rings, to be successful, not different lens mounts. If you find one very inexpensively, it may be worth experimenting to see what you think. You might need a step-up ring or two to fit your chosen lens. They were originally intended to be used on roughly "normal" lenses, like around 50mm focal length or thereabouts.

02-06-2023, 06:23 AM	#4
ramseybuckeye Site Supporter Join Date: Apr 2009 Location: Hampstead, NC Photos: Gallery Posts: 17,295	Might be an ok fun thing to experiment with if it’s cheap enough. I’m sure it will reduce image quality, but a good way to decide if you want a fisheye lens. I had a fish eye once and tired of it pretty quickly, though some people love them.

02-06-2023, 07:30 AM	#5
35mmfilmfan Pentaxian Join Date: Oct 2016 Location: Norfolk, UK Posts: 4,338	I've used one on a Pentax-M 28mm lens - as others say, fun to play with. if you actually want to obtain consistent results, a tripod and spirit level are worth considering, to avoid unintentionally wonky horizons. I think you might run into major focusing difficulties trying to mount it on a reversed lens, though I have no doubt an adapter could be constructed to make this possible - which would probably cost more than the fish-eye adapter !

02-06-2023, 10:43 AM	#7
Thagomizer Pentaxian Join Date: Jun 2014 Location: London Ontario Posts: 2,068	I picked up a "Semi Fish Eye" to play with. I'm not where it is right now, and I don't recall the brand. On APSC I'm just losing the corners with a 35mm lens. Here's the original shot: ...and the cropped version: Ready to Explode I haven't used it much since my initial test drive, but It's pretty fun. You want to be careful that you don't overuse it, but with careful handling and the right subjects, it can provide striking results for not a lot ogf outlay. As I'm not ready to get an actual dedicated fish-eye lens, this will do for now.