fisheye lenses

this may sound like a stupid question, but, what is the advantage of a fisheye lens? i have a 17-40 lens for my canon 5d. would a fisheye lens provide an advantage over this lens?

I am a newbie but as I understand.....

Fisheye will let you get MUCH closer to the subject and still let you fill the frame. This reduces the water column between you and the subject.

17-40 zoom will work as a good lens if you are unsure of what you may see on a dive (fish portraits, sharks, reef- but not too wide). Fisheyes are more for seascapes, reef pics, etc....

Fisheyes have a look thats difficult to approximate with a regular wide-angle lens. It allows you to fill the frame with a near subject while at the same time making backgrounds look distant which is what all wides do, it's just that FE's do it a lot more. When the background looks farther away it enhances the perceived visibility and when you can shoot closer to the foreground your subject will be sharper with better contrast.

AND, you'll never get a WA lens as wide as you can with a fisheye. Fisheyes go all the way out to 180 degrees, while the widest rectalinear lenses go to only about 120 degrees.

FE lenses are also much cheaper and corner sharpness is also much better. Focusing is also closer. So optically, if you can live with the distortion they are better.

so ... any recommendations for a good fisheye lens for a canon 5D?

There are two choices. The Canon 15mm, and the Sigma 15mm.

The Sigma is slightly cheaper and focuses closer.

The canon, has the letters CANON written on the side of it.

Both are excellent lenses, you really can't go wrong.

My experience with Sigma lenses has been that the focus goes very slow. I had the Sigma 105mm Macro and it took forever to focus, and usually took several tries. I recently switched to a Canon 100mm USM and it focuses like a laser beam. I'm getting shots that I never could with the Sigma, like juvenile fish darting around. I believe this is true because Sigma lenses aren't officially supported, they have to "hack into" the Canon autofocus system.

I don't have experience with either manufacturer's fisheye lens, but based on my experience with the macro I would definitely opt for the Canon lens.

My experience with Sigma lenses has been that the focus goes very slow. I had the Sigma 105mm Macro and it took forever to focus, and usually took several tries. I recently switched to a Canon 100mm USM and it focuses like a laser beam.

You're comparing apples to oranges. The Canon EF15mm FE and the Sigma EX 15mm FE pretty much have the same focus speeds. They both do not use USM/Hypersonic motors for focusing. The EF100 USM macro does use the Ring type USM whereas the Sigma, Tamron and old EF 100Macro that all extend during focusing use older motors.

I've shot both 15mm's and you can't tell the difference between the 2, except for a lighter wallet by going with Canon. The Sigma FE is the only non Canon lens I own.

s.

I use a Canon 15mm with a 5D and a smallish port - its not just about the lens, you have to make sure that your port is viable with the lens too. Also lighting for a fisheye is very different. Its not quite as simple as just getting the lens - but if you decide to I can recommend the Canon - and its likely that it will have a better resale value if you don't like it.

You're comparing apples to oranges...

It wasn't just the motor speed difference on the Sigma lens, it would hunt and hunt for focus and never find it. And this is on a 5D which has a bunch of autofocus zones. I understand that the fisheye lens has a different focus mechanism, but they share the same "hacked" connection to the focus mechanism. I think the camera body will be happier with a Canon lens.

Not much to add as much of it has already been said. The fisheye lens will definitely give a wider angle of view than a rectilinear wide angle, however, the FE there's going to be a fair bit of barrel distortion. Depending on how you frame your shot, the distortion may not be noticeable (it is certainly less pronounced underwater than it is on land if you're just playing around with it out of the water). This can, to some degree, be corrected using software (Photoshop has a lens correction feature which can reduce the barrel distortion effect). If you frame a shot that has straight lines near the periphery of your frame, you will notice this distortion quite a bit.

I can't speak about the Sigma 105mm, but as for fisheyes, focus speed is really a non-issue. These things focus fast because they hardly have to do anything. Nearly everything is in focus from 3'-infinity, only a slight change is required for close in.

I have the Sigma 15mm for Nikon and its quite fast, just as fast as the Nikon 10.5. I sincerely doubt its different on Nikon.

Long macro lenses are a completely different animal. Precise focus is hard because DOF is very thin at macro distances on a long lens. The lens has to travel a long distance to focus from close in to infinity, making the motor more important as well. You need a lot of light to get good focus. Even then, the Canon lens is universally regarded as the fastest focusing 100mm macro. I'm not suprised that the Canon focuses faster in this case. I'm sure its not because of the implementation.

I agree with acroporas, the Sigma lens is a better lens because it focuses closer for CFWA or WA Macro. RE-sale is better on things that say CANON on the side but if you care about the re-sale of a lens you are setting out to buy, I think its misguided.

Has anyone used a Sigma 8mm?

http://www.sigmaphoto.com/lenses/lenses_al...asp?navigator=4

I'm considering it for topside stuff (stitched panoramic shots).. was wondering how it'd perform underwater.

Has anyone used a Sigma 8mm?

Not that I have seen - crikey, I have had problems lighting the Nikon 10.5 so an 8mm would be interesting.

Love to know how you go about stitching pano's together from a fisheye - but that will tend to drag things way off subject I suppose.

Paul C

Not that I have seen - crikey, I have had problems lighting the Nikon 10.5 so an 8mm would be interesting.

 

Love to know how you go about stitching pano's together from a fisheye - but that will tend to drag things way off subject I suppose.

 

Paul C

Lots of examples on flickr, good stitching software (like Hugin) can deal with radial distortion

this is with an 8mm lens

http://www.flickr.com/photos/jftphotograph...in/photostream/

and here's a fun sterographic view

http://www.flickr.com/photos/jftphotography/530526068/

I'd like to try this underwater!

The 8mm produces a circular view. Most people aren't enamoured by circular shots. The 15mm is a specialist lens. The 8mm is really a unique specialist lens. If you just want good reef panoramas, eye popping CFWA, and sharp shots of big creatures you don't want an 8mm.

You might also have trouble putting it into a dome.

For certain artistic work I could see the value of circular perspective. It does strange things with round objects (inside of a spone perhaps, or a shark's mouth ) And it could be unique. But I wouldn't want it as my first WA.

Panoramas is what its for. These could be very interesting underwater. I'd love to see the results if someone wants to try it. But again, there's much more to shoot than panoramas with a normal FE lens.

Here is an article: http://www.shutterbug.com/newsletter/062607sigma/

Hi Matt,

Perhaps some examples might help you with your choice.

The first image is a fisheye focused very close, in fact you can see that the dome is pressed into the subjects chest which is conforming around the port. You can see that the interface between the above water part of the shot and the below water part cause the waterline to curve upward near the subjects chin. The fisheye also makes the subjects nose and lower lip and cheeks look very large because they are closer to the lens than his eyes and his ears are completely covered. This type of distortion is common with these non- rectilinear lenses.

In the second image I moved back to about ten inches and things look much more normal as long as the subject is centered, however the sky above is rounded and the light falls off toward the outside of the frame.

As the subject is moved off center towards any of the edges of the frame the distortion will return.

The third image is with a rectilinear lens which would be the same as a 14 mm on your 35 mm chip camera.

The foreground subject is still about 8 to 10 inches from the dome but appears much less distorted in relation to the background even at the 114 degree angle of view. This was taken with a 220 mm dome port. Smaller and less expensive ports will work better with the fisheye lenses than with the wide rectilinear lenses.

Phil Rudin

Blimbo,

I've made spherical panoramas underwater and displayed them both as VR panoramas and tried stereographic reprojections. I used a 5D and a Tokina 10-17, at the 10mm end, and found I had to cut off the lens shade (a tricky operation!). I also have the sigma 8mm and have tried housing it, but yet to put it underwater- looks like it will work though, in the right dome. The Tokina projects a larger circle (albeit a cropped one), so you end up with a higher res panorama- I can get the full 360 by 180, with plenty of overlap for stitching with four shots around. I had to custom build a panoramic tripod head. You need plenty of weight to hold the tripod steady- and good subject matter. I'm hoping to do some more next month in the Red Sea.

Fergus

I've made spherical panoramas underwater and displayed them both as VR panoramas and tried stereographic reprojections. I used a 5D and a Tokina 10-17, at the 10mm end, and found I had to cut off the lens shade (a tricky operation!).

Hi Fergus,

Do you have any shots with your Tokina 10-17 & 5d combination you can post here? I am curious if you get the same kind of results as on a cropped camera (e.g. D200). I would be very interested in learning more about your DIY project.

Cheers,

Vincent

Hi Matt,

 

Perhaps some examples might help you with your choice.

 

 

Phil Rudin

Nice shot there showing things. I am going through the same debate myself, I am leaning to the rectilinear (probably the Canon 10-22, actually have it on hold right now) as the next pick up for what I think my above and below water use in the near future will be.