Oh my God! Lens comparison question

[evilenglishman]

:shock: sorry :shock:
I want to create images with a bit of barrel distortion. I'm not sure if a fisheye would be too much distortion though - are there any crappy lenses that do it by accident?

I've looked at FM reviews on the Canon 15mm F2.8 and the Sigma AF EX 14mm f/2.8 Aspherical. Both have similar results as far as reviewers go and the lenses are closely matched.

The only differences are:
Diaphram Blades:
Canon = 5
Sigma = 7
Lens Construction (Groups/Elements):
Canon = 8/7
Sigma = 10/14
Minimum Focusing Distance:
Canon = 20cm
Sigma = 18cm
Magnification:
Canon = 0.14
Sigma = 1:5

There are a few physical differences too. The Sigma costs slightly more. Overall it 'looks' like the sigma is worth the extra money.

Can anyone point me to other reviews or has anyone got any experience with either lens?

I'm not really interested in buying a russian one.

[ron chappel]

Just to be exact,do you mean the distortion you get from being real close to something (perspective distortion)?In which case any close focusing wide angle will probably do nicely

[Scottes]

I want to create images with a bit of barrel distortion. I'm not sure if a fisheye would be too much distortion though - are there any crappy lenses that do it by accident?

I'm sure there are but do you really want to put up with the crappy contrast and chromatic aberrations?

And are you really looking for barrel distortion or do you want the look of an almost-fisheye? I guess I equate "barrel distortion" as being a poor design and a mistake. Fisheyes are supposed to have their look, and generally they must do it well or it looks like a mistake.

Can't you simulate in PS? Or do you plan on making a lot of shots like this?

[iwatkins]

Have you considered the Sigma 12-24mm ? I have a lot of fun with it.

Cheers

Ian

[evilenglishman]

i would like straight lines to be curved but not a complete fisheye type distortion.
Its difficult to explain without an example :?

I'm pretty much set on one of those lenses but cant make up my mind as there seem to be little between them :shock:

[Andy_T]

Have you taken a look at the Zenitar 16 mm 2.8 mf rectilinear fisheye?

From the example photos I've seen so far, the fisheye effect is not very pronounced with this lens (see thread http://photography-on-the.net/forum/showthread.php?t=23790&highlight=zenitar.

Best regards,
Andy

[roanjohn]

Just to be exact,do you mean the distortion you get from being real close to something (perspective distortion)?In which case any close focusing wide angle will probably do nicely

Your "L" Dog is sooo funny!!!

Ro1

[justme_dc]

The Canon 15mm fisheye has a diagonal viewing angle of 180 deg. same as the Sigma 15mm fisheye. The simga 14mm has a viewing angle of 114.2 deg. It is also corrected for distortion on the horizontal plane just like the canon 14mm by use of aspherical lens elements. That is not to say that it will not barrel distort, because it will, but it is far less obvious than the effect of a fish eye. In fact, the barrel distortion is very hard to detect unless you force perspective by shooting really close at a hard angle. Keep in mind that the FOV crop of 1.6 will remove some distortion via cropping. As the 14mm only distorts on the outer edge of the frame (it's really well corrected) you'll end up with an effect much like a 20mm lens on a fullframe camera. I have a 15mm fisheye and a fair amount of it's trademark distortion is lost on my 10D.

If you have the ability to rent one of each and compare them, I'd suggest doing so.

[EXA1a]

:shock: sorry :shock:
I want to create images with a bit of barrel distortion. I'm not sure if a fisheye would be too much distortion though - are there any crappy lenses that do it by accident?

I've looked at FM reviews on the Canon 15mm F2.8 and the Sigma AF EX 14mm f/2.8 Aspherical. Both have similar results as far as reviewers go and the lenses are closely matched.

The only differences are:
Diaphram Blades:
Canon = 5
Sigma = 7
Lens Construction (Groups/Elements):
Canon = 8/7
Sigma = 10/14
Minimum Focusing Distance:
Canon = 20cm
Sigma = 18cm
Magnification:
Canon = 0.14
Sigma = 1:5

There are a few physical differences too. The Sigma costs slightly more. Overall it 'looks' like the sigma is worth the extra money.

Can anyone point me to other reviews or has anyone got any experience with either lens?

I'm not really interested in buying a russian one.

As justme_dc made clear, these two lenses are TOTALLY different beasts. A fisheye looks very different from a rectilinearly corrected lens at the same focal length.
If you need "just a bit" of distortion, I'd recommend to do it on the computer. Either way - you can shoot semifisheye and correct it to a certain amount (that's waht I do with a Sigma 15/2.8 FE) or you can shoot corrected and distort a bit in postprocessing.

--Jens--

[evilenglishman]

thanks for the info guys.
I understand the difference but with the crop factor there doesn't appear to be that much difference between them.

From looking at examples it seems the canon doesn't have much distortion at all on a 10D, D60 etc

http://www.pbase.com/image/20660772
http://www.pbase.com/image/23798646
http://www.pbase.com/image/22071877

On a 1D its a diiferent story though (obviously):
http://www.pbase.com/image/25622779
http://www.pbase.com/image/16940769

The sigma has very similar results:
http://www.pbase.com/image/277845
http://www.pbase.com/image/27719220

The sigma 15mm has a more pronounced effect:
this is nice!! http://www.pbase.com/image/27171348
http://www.pbase.com/image/26956055
http://www.pbase.com/image/21852334

I would like to see what the 8mm sigma looks like on a 10D/D60 etc

[EXA1a]

thanks for the info guys.
I understand the difference but with the crop factor there doesn't appear to be that much difference between them.

When you look at a real life picture, sometimes you cannot tell if a fisheye has been used. The reason for this is the general misconception that a fisheye "distorts" and a rectilinear lens does not distort. See this thread for more on this topic:
http://forums.dpreview.com/forums/read.asp?forum=1029&message=7283552

--Jens--

[justme_dc]

The sigma 15mm has a more pronounced effect:
I would like to see what the 8mm sigma looks like on a 10D/D60 etc

Actually the reason that I have the Sigma 15mm fisheye as opposed to the canon version is that the Canon seems to be corrected to a certian extent. The Sigma is VERY fishy.

The 8mm will work really well with a 1.6 FOV crop. It has a 22.08mm image circle the Canon 1.6 FOV crop cameras have a 22.7 x 15.1 mm CMOS sensor. That means that the image circle covers the vertical aspect of the sensor completely and the horizontal is only short by 0.62mm at the widest point. Granted it is a circle so it will be shorter in the corners. By my quick and dirty calculations you should have image coverage measuring 16.381x15.1mm. Just slightly over square. Of course you colud crop it differently and get a more rectangular image.

[Jussuff]

NO retouch, just resized for web.

http://www.jot-gallery.com/gallery/photos/big/133_3354.JPG

You will find further details of this capture at
http://www.jot-gallery.com/gallery/photo.php?photo=60