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DPChallenge Forums >> Hardware and Software >> Canon Fisheye Vs Sigma Fisheye
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09/10/2006 07:40:16 AM · #1
I'm thinking about lashing out and getting a Canon EF 15mm f2.8 Fisheye lens. Being a Canon boy from the start of my digital awakening, I'm tempted to remain faithful. However the Sigma EX f2.8 fisheye equivalent is significantly cheaper, has anyone out there used one or both of these and what are your thoughts/reccomendations. Thanks
09/10/2006 07:50:12 AM · #2
I'd get a Sigma 10-20...just in case my opinion counts for anything at all.
09/10/2006 08:00:49 AM · #3
Have you seen a 15mm fisheye on a 1.6 crop camera? The results arent really much of a fisheye more of a wide angle with some distortion on the edges. When I was looking for a fisheye I looked at the 15mm and the 8mm Peleng, the difference was significant. I bought an 8mm Peleng, but I struggled with manual focus. My recommendation would be that if you want a fisheye effect that you get something wider then the 15mm. If you just want a wide angle then get one of the zoom wides like the Tokina, Tamron, or Canon.

MattO
09/10/2006 08:03:05 AM · #4
Originally posted by deapee:

I'd get a Sigma 10-20...just in case my opinion counts for anything at all.


what he said! the Sigma 10-20 is all the wide angle you could ever want for a real bargain price!
09/10/2006 08:12:49 AM · #5
Thanks for your thoughts everyone
09/10/2006 08:16:29 AM · #6
Originally posted by LoveSpuds:

Originally posted by deapee:

I'd get a Sigma 10-20...just in case my opinion counts for anything at all.


what he said! the Sigma 10-20 is all the wide angle you could ever want for a real bargain price!


agreed...I have the 10-20 and I think it is perfect and sharp...I tried the 15mm (or so) Nikon and I really couldn't see a benefit over my 10-20mm
09/10/2006 08:23:11 AM · #7
8mm Fisheye Effect
09/10/2006 10:29:47 AM · #8
I've used a friends 15mm canon fisheye on my 30D (he has a 1D mk2 n). He gets fisheye, I get, umm, not fisheye. Like Matt says, you get wide angle with some distortion.

Sorry.
09/10/2006 10:34:28 AM · #9
I'm not sure but if you're looking for the widest of the wide without going to something like Peleng 8mm, the Sigma 15mm fisheye on a 1.6x crop DSLR gives you an even wider view than the Sigma 10-20mm or the Canon 10-22mm. However, you do have the de-fish the image somewhat.
09/10/2006 10:42:27 AM · #10
You can't get a wider picture from a 15mm than you can from a 10mm lens. If you do, then the 10mm lenses are not really 10mm or you are getting part of the image vignetted by the lens shade or end of the lens barrel. Unless Sigma has found a way to twist the physics of light through a lens somehow. 5mm is a big difference in view area and would be very noticable. I know 4mm was very noticable when I went from 28mm to 24mm on a 10D camera.

Mike

Message edited by author 2006-09-10 10:43:51.
09/10/2006 10:47:19 AM · #11
Originally posted by MikeJ:

You can't get a wider picture from a 15mm than you can from a 10mm lens...

Mike


Yep, you can. it's because the "mapping" of the fisheye lens is different than a rectilinear lens. It's the optical design. That's why straight lines appear curved in a fisheye lens. FWIW, the usual mapping for a fisheye lens is "equiangular", meaning that for ever millimeter you move away from the center of the image, the change in angle is the same. It's not the same for WA rectilinear lenses, where 1mm at sensor center is a greater angle than 1mm at sensor edge. You can see this when you look at objets near the RH and LH edges of the frame with a rect. WA lens, they are stretched horizontally.

Edit: on a 1.6-crop cam, the 15mm fisheye lenses give about the same AoV as an 11mm rectilinear lens.

Message edited by author 2006-09-10 10:48:06.
09/10/2006 01:35:43 PM · #12
sigma has an 8mm

reviews here
whoops - the fr reviews are for an old version. they have new digital version (see top link)

Message edited by author 2006-09-10 13:39:26.
09/10/2006 02:16:28 PM · #13
Originally posted by dahkota:

sigma has an 8mm ...

Sweet. But (gulp) $900! I need to win the lottery... ;^)
09/10/2006 05:50:56 PM · #14
It may map different, but when you start talking about degrees of view, it's either 15mm or 10mm or what ever it's said it's suppose to be. But if it can see more than what it's rated at, then it's rated view is not correct. It's like saying you went 60 miles in an hour while only doing 55 mph or putting 7 gallons of water in a 5 gallon bucket. Not to be confused with spending more money than we make... we all know that that is possible. ;D

Mike

09/10/2006 06:19:19 PM · #15
A picture comparing the 10mm, 12mm, 15mm fisheye and a couple of other focal lenghts is at //forums.dpreview.com/forums/read.asp?forum=1029&message=11982207

The 15mm fisheye may have a greater diagonal angle of view than a 12mm rectilinear lens, but it doesn't cover the same area.

Message edited by author 2006-09-10 18:21:48.
09/10/2006 06:35:22 PM · #16
Originally posted by glad2badad:

Originally posted by dahkota:

sigma has an 8mm ...

Sweet. But (gulp) $900! I need to win the lottery... ;^)

Nah...that's MSRP. B&H has the 8mm for Canon in stock here. They didn't carry the KM mount, only Sigma4Less did (out of stock). Sunshine Electronics (never heard of them) has it for $580 + shipping.
09/10/2006 08:15:05 PM · #17
Originally posted by MikeJ:

It may map different, but when you start talking about degrees of view, it's either 15mm or 10mm or what ever it's said it's suppose to be. But if it can see more than what it's rated at, then it's rated view is not correct. It's like saying you went 60 miles in an hour while only doing 55 mph or putting 7 gallons of water in a 5 gallon bucket. Not to be confused with spending more money than we make... we all know that that is possible. ;D

Mike


I think you missed the point. Because the mapping is different (a result of a different optical design), an equiangular fisheye with the same focal length as a rectilinear lens will have a greater angle of view.
Let's consider a specific example. A 15mm equiangular fisheye and 15mm rectilinear lens are each used on a full-frame 35mm camera (36mmx24mm sensor size). What are the respective angles of view. Answer:

Rectilinear:
Diag. AOV = 111°
Horz. AOV = 100°
Vert. AOV = 78°

Fisheye:
Diag. AOV = 185°
Horz. AOV = 147°
Vert. AOV = 94°

As an aside, a fisheye lens can have an AOV greater than 180 degrees. For a rectilinear lens, it's mathematically impossible.
09/11/2006 03:57:39 AM · #18
if you want wide views on a cropped sensor, I'd recommend an ultrawide.
If you are looking for a fisheye look, then a Peleng 8mm fisheye may be an acceptable option.
09/16/2006 04:38:25 AM · #19
Searching the forums here for an answer to my fisheye vs. 1.6 crop issue.

I am very close to buying an EOS 400D, and I when I look after fish eye lenses that might fit it, they say 180 degrees for 35 mm. With the crop factor of 1.6, how much is that? Will there be a difference between 8 mm fish eye and 15 mm fish eye? Would be stupid to fork out money for a fish eye when it does not give even close to 180 degrees.

What I am considering is either

Canon 10-22 (non fish eye)

or

One of the Sigma fisheye lenses, either 8 or 15 mm.

I wish that //forums.dpreview.com/forums/read.asp?forum=1029&message=11982207 had included an 8 mm fish eye ...

Just for wide shots - not that concerned that it either HAS to be fishy or not!

Message edited by author 2006-09-16 04:41:02.
09/16/2006 08:48:16 AM · #20
The 15mm fisheye lenses on a 1.6-crop camera will give about 108° diagonal FoV, and 89° horozontal FoV. An 8mm will give 180° diagonally but leave dark corners (image circle does not cover all of the sensor) and about 170° horizontally. These figures assume the lenses are precisely 8 and15mm focal lengths (actual lenses might be slightly different) and is based on a 22.7x5.1mm sensor size. Your sensor might be a little different, but the difference in FoV will be small.
For comparison, a 10mm rectilinear lens on a 1.6-crop gives about 107° diagonally (97° horizontal)
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