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05-29-2012, 08:20 PM   #31
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+1 for stitching if you want wide perspective and don't care about fisheye distortion. For me, the distortion is part of the fun of using a fisheye.

I have tried stitching recently and it's pretty nice. Here is an example of stitching 6 images:



It may not look impressive at this size, but the resulting size was 40MP - plenty of detail in there. Cooled off my interest for wider angle lenses than I already have.

05-31-2012, 04:21 PM - 3 Likes   #32
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There are several old threads on the Samyang 8mm and fisheyes.

IMHO fisheye lenses can get a bit boring after a while. You get one, take the usual shots of a flying skateboarder, up the nose of a donkey/dog/child or of a building and you'll find that they all begin to look the same - fisheyed.




Although if you line up the horizon and are careful about the composition you can sometimes hide the distortion.




You might discover 360 degree panoramas - a whole new word. The Samyang 8mm excels at this since because of the unusual projection most of the time you only need six shots. With a decent software (e.g. Autopano) stitching is largely automatic and easy. And with a bit of care you can easily shoot 360 panos handheld.

- there are 360 degree viewer links on the Flickr page or try 360cities.

The lack of AF on the Samyang is largely irrelevant since at 8mm and stopped down a bit just about anything from a few inches away to infinity will be in focus.




De-fishing the Samyang is not that hard with PTLens and a bit of twiddling. You could probably also go the other way and 'fish' a rectilinear shot but it won't be easy.



Otherwise get the Pentax 10-17mm. At 17mm it is not at all fishy. And you get AF.




But since you already have an ultra-wide rectilinear you don't need that. If you do get the Samyang 8mm, you'll find that the extra 2mm plus the Samyang projection does make a great difference - https://www.pentaxforums.com/forums/pentax-slr-lens-discussion/172414-fisheye...ml#post1826650

Last edited by kh1234567890; 03-06-2013 at 02:06 PM.
05-31-2012, 05:28 PM   #33
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@kh1234567890 Good read, it's like reading a story book with pictures (:
05-31-2012, 07:14 PM   #34
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QuoteOriginally posted by kh1234567890 Quote
There are several old threads on the Samyang 8mm and fisheyes.
Thank you very much for these images !
It looks like the defishing went quite OK in your example.
The panorama possibilities are definitely interesting and I would have to explore them.
If they can be done without tripod as you imply, then I'm definitely up for that.

QuoteQuote:
But since you already have an ultra-wide rectilinear you don't need that. If you do get the Samyang 8mm, you'll find that the extra 2mm plus the Samyang projection does make a great difference - https://www.pentaxforums.com/forums/pentax-slr-lens-discussion/172414-fisheye...ml#post1826650
Indeed!

Thank you very much for the link to that discussion. In it, I found another link at Samyang Fisheye Lens short review .

This says that the Samyang lens is marketed as Opteka 6.5mm, and Vivitar 7mm !

I found a seller on Amazon that will sell the later new for $259.99 + shipping. Actually one Amazon seller has the Rokinon 8 for $260 also.

I couldn't find the Opteka 6.5mm in Pentax mount. It seems to be available for Olympus mount only on ebay, at $249.95.

Not sure which one is the better brand to get, but these prices are awfully tempting.

06-01-2012, 01:05 AM   #35
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I think that they are all the same lens. With this fisheye the exact focal length is probably not easy to measure

360 panos without a tripod - - easy ! Check out 360 cities.

Get one - it is a fun lens. The biggest problem is keeping your feet out of the shot ! And whether to tweak or not to tweak the focus calibration - google "samyang 8mm focus calibration".
06-01-2012, 01:19 AM   #36
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QuoteOriginally posted by kh1234567890 Quote
I think that they are all the same lens. With this fisheye the exact focal length is probably not easy to measure
Indeed. And we should consider specification tolerance. I've read that the FA50/1.4 is actually 53/1.5, which is within 10% tolerance. If a lens sold as 6.5|7|8mm is actually 7.2mm, it's within 10% of all those. And measuring decimillimeters is tricky.

I'll suggest that the geometric projection has a greater impact on the AOV than does the specified focal length. Watch out for lenses with AOV greater than 180 degrees -- when they see behind themselves, the togger can never escape (except by using a remote).
06-01-2012, 01:44 AM   #37
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QuoteOriginally posted by RioRico Quote
Indeed. And we should consider specification tolerance. I've read that the FA50/1.4 is actually 53/1.5, which is within 10% tolerance. If a lens sold as 6.5|7|8mm is actually 7.2mm, it's within 10% of all those. And measuring decimillimeters is tricky.
It is not so much the tolerance as the type of projection with the Samyang - on axis it is probably over 8mm, off axis it might measure less than 8mm. If you were the marketing person, which one would you choose ?
06-01-2012, 02:42 PM   #38
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The Samyang fisheye is a great lens if you want a fisheye. I reviewed it here. I am thinking of selling mine to replace it with the MFT version.

06-01-2012, 03:55 PM   #39
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Well, I pulled the trigger on the Samyang 8, Rokinon brand. It was shipped today, and I'm expecting it some time next week
06-11-2012, 04:19 PM   #40
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Got my Samyang 8mm fisheye last friday. I played with it over the weekend. It's very nice !

However, I am not able to use it with my Canon body. I also received a cheap PK-EOS adapter from China.
For one thing, it doesn't hold the lens securely. When removing the lens, the adapter stays on the camera sometimes.

But more importantly, there is very severe vignetting with the 8mm fisheye on the Canon body. It's not uniform. There are some very large black bands on the top left and bottom right of the image. That makes it completely useless. I don't understand why.

The PK-EOS adapter does work fine without vignetting with the Pentax-F 50mm 1.7, my only other lens with an aperture ring . Though it still doesn't hold it well.
06-11-2012, 07:21 PM   #41
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QuoteOriginally posted by madbrain Quote
Got my Samyang 8mm fisheye last friday. I played with it over the weekend. It's very nice !

However, I am not able to use it with my Canon body. I also received a cheap PK-EOS adapter from China.
For one thing, it doesn't hold the lens securely. When removing the lens, the adapter stays on the camera sometimes.
This may be common to all versions of the lens when used with adapters, and is covered in section 3.3 of this review:

"However, when the lens is used with third party adapters or accessories, the lens may fit so loosely that it wobbles on the mount. This is the case when the lens is used on a third party Nikon to Olympus 4/3 lens mount adapter."

QuoteOriginally posted by madbrain Quote
But more importantly, there is very severe vignetting with the 8mm fisheye on the Canon body. It's not uniform. There are some very large black bands on the top left and bottom right of the image. That makes it completely useless. I don't understand why.
That's because it is designed to be an APS-C lens, and they built the hood with that in mind. This is covered in all the reviews I have read, for instance Photozone's review:

"You can also mount it to a full format (35mm) DSLR but the build-in lens hood will be visible in the image field in this case."

(Section 3.3 of Jeffry R. Charles' review above covers what's involved in cutting off the hood permanently if you want to sort-of convert it for full frame use.)

QuoteOriginally posted by madbrain Quote
The PK-EOS adapter does work fine without vignetting with the Pentax-F 50mm 1.7, my only other lens with an aperture ring . Though it still doesn't hold it well.
Sounds like adapter you're using could also be a factor in how well it mounts, but you may need more experiential data points to know for sure.
06-11-2012, 07:37 PM   #42
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naster,

QuoteOriginally posted by nater Quote
This may be common to all versions of the lens when used with adapters, and is covered in section 3.3 of this review:

"However, when the lens is used with third party adapters or accessories, the lens may fit so loosely that it wobbles on the mount. This is the case when the lens is used on a third party Nikon to Olympus 4/3 lens mount adapter."
It's not wobbling, there is just a little notch on the PK-EOS adapter that is slightly too long. It's supposed to snap on one part of the mount, but is too long, so it doesn't snap. The same problem happens with both lenses I tried with that adapter. It's not specific to the 8mm Samyang. I think it's just a cheaply made adapter.

QuoteQuote:
That's because it is designed to be an APS-C lens, and they built the hood with that in mind. This is covered in all the reviews I have read, for instance Photozone's review:

"You can also mount it to a full format (35mm) DSLR but the build-in lens hood will be visible in the image field in this case."

(Section 3.3 of Jeffry R. Charles' review above covers what's involved in cutting off the hood permanently if you want to sort-of convert it for full frame use.)
I know about that problem, but my Canon Rebel T3i is also APS-C . It is not full-frame. So I don't see why I am getting the vignetting.

Julien
06-12-2012, 09:29 AM   #43
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QuoteOriginally posted by madbrain Quote
I know about that problem, but my Canon Rebel T3i is also APS-C . It is not full-frame. So I don't see why I am getting the vignetting.
I would assume the lens doesn't mount straight (because you seem to have a pretty crappy adapter). If so, you should also get a tilted plane of focus, but that might be a bit hard to see on an 8mm lens. Or possibly it doesn't mount in the center, but that seems less likely.
06-12-2012, 01:53 PM   #44
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QuoteOriginally posted by drougge Quote
I would assume the lens doesn't mount straight (because you seem to have a pretty crappy adapter). If so, you should also get a tilted plane of focus, but that might be a bit hard to see on an 8mm lens. Or possibly it doesn't mount in the center, but that seems less likely.
Don't know. But FYI, this is what the vignetting looks like. Pretty awful !

Last edited by madbrain; 08-30-2013 at 06:10 PM.
06-12-2012, 02:23 PM   #45
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Well, that is certainly a form of "not straight", though not the one I meant. The lens is rotated compared to how it's supposed to be mounted, leaving what should be the upper and lower part of the hood on the sides like that. You can cut it off, but I think using the lens on a camera where it mounts properly would be a better solution.
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