Which fisheye for a full frame camera (6.5 - 8mm)

I purchased a Rokinon 6.5 mm fisheye and am shocked at the quality of the image considering the price that was paid.

Problem is it is only for crop sensors. It mounts on a FF camera, but has to be cropped so much the image is unusable to me.

Which fisheye (6.5 mm - 8 mm) will produce a full frame image on a FF camera?

Fully manual is desirable to save money.

I have looked on google and elsewhere such as amazon but cannot find a good solution. Tons of fisheyes are available, but all for crop sensors.

No more than 8 mm and ~180° field of view desired.

I think your 8mm max is misguided. The 180-degree fisheye lenses for full frame are 12mm & 15mm. I have the Sigma 15mm f/2.8 Fisheye, and the Rokinon 12mm f/2.8 Fisheye. Both are 180 degrees and completely cover the full frame image sensor. An 8mm lens on full frame with leave you with a circular image in the center of the frame.

Are you looking for 180 deg. covering the full frame, or 19=80 deg. with a circular image? Most FF fisheyes in the 8 mm range have been restricted to a circular image; even Canon's 8-15 zoom gives a circular image on FF.

There are two kinds of fisheye lenses, basically.

A diagonal fisheye lens shows a 180 degree AOV across the entire frame, from corner to corner diagonally across the frame. This AOV will allow the image to fill the entire sensor, but only the longest possible distance (corner to corner on the diagonal) will be 180 degrees AOV. A 15mm lens (non-rectilinear) will be a diagonal fisheye on a FF (35mm) camera.

A circular fisheye lens shows a 180 degree AOV across the short axis of the frame. The lens cannot show anything beyond the 180 degree AOV, so everything outside that will appear black. The appearance then will be a circular image surrounded by black. The circle will just touch the edges of the frame on both sides (across the short axis). A circular fisheye lens on a FF (35mm) camera will be a non-rectilinear 8mm focal length lens.

There have been a very few specialized lenses that can see beyond 180mm AOV, meaning they can look behind the camera. I think there was a Nikon lens with such a design, but the front element was this giant piece of curved glass (the lens weighs 5.2kg!). The lens is the Nikkor 6mm - f/2.8 (220 degree AOV), and they tend to sell for over $100,000 when they show up on the used market these days.

For FF i think you're limited to the 12mm Samyang/Rokinon.

I probably should have also said, looking at these two types of lenses here are the cheapest FF options I can see:

If you want a circular fisheye, there is a Rokinon 8mm f/3.5 for EOS mount that runs about $250.

If you want a diagonal fisheye, there is a Rokinon 12mm/2.8 for about $500 and a Sigma 15mm/2.8 for about $550.

JeffreyG is bang-on. I just paid $499 (At Adorama - THE GREATEST STORE IN THE UNIVERSE!) for my Rokinon 12mm f/2.8 FE. It should be here Monday. The Sigma 15mm f/2.8 FE is also 180-degree diagonal. I got mine for $425 - used.

JeffreyG wrote in post #17816473
If you want a circular fisheye, there is a Rokinon 8mm f/3.5 for EOS mount that runs about $250.
.

Just be careful when buying the Rokinon 8mm lens for a full frame. There are two different models. One has an built in lens hood and the other one comes off. The one with the removable hood is the one you want for a full frame camera. If you take a photo with the the one with the non removable lens hood with a crop sensor it shows as a rectangular image with the long edge being 180 degrees. If you take the photo with a full frame, the lens hood creates a photo with a "squeezed in on the sides" kind of look.

The $250.00 USD version is usually the one with the built in lens hood. The lens with the removable hood is about $100.00 more. The hood can be cut off if one wishes, but then you lose the functionality of the hood.

Thank you all for your replies. I was going to multi-quote, but everybody had something useful to add. I am not experienced with fisheye lenses so everything was helpful.

A little more info, as brief as possible.

First, a mistake. The lens I purchased was not a Rokinon but this Opteka. For the price I paid ($150) I am very happy (shocked) with the image quality.

I shoot primarily with three cameras: 5D2, T3i, and 5D. The Opteka on the T3i creates superb full frame images - great wide angle distortion style edge-to-all-edges. But on the 5D it creates the full sphere images, surrounded with black. Cropping these down to full frame edge-to-edge nets a very small image.

My desire is to get the same edge-to-edge wide angle, 180 degree distorted look on the 5D.

As to why, it is because the 5D is an IR conversion and I want the style when shooting IR.

So I only have two choices:

a) Buy another crop camera such as another T3i and have it converted, or
b) Buy a fisheye that can be used on the FF 5D.

I figure both will cost about the same, but (b) buying the new lens will have the added bonus of also being used on the 5D2. It would also mean I can put the Opteka on the T3i and the new lens on the 5D and shoot without lens changes.

Hope that makes sense. It is very important to me to get the distorted wide angle fisheye effect when shooting IR, but again I do not have a crop sensor IR conversion so cannot presently do so without unacceptable cropping.

Again, thanks for the info.

OP - What you want is a diagonal fisheye. Get the Sigma 15mm or Rokinon 12mm.

JeffreyG wrote in post #17816562
OP - What you want is a diagonal fisheye. Get the Sigma 15mm or Rokinon 12mm.

Jeffrey,

Thank you very much. The amazon price on the sigma is $559, and the rokinon is $379. Both in the ballpark I was expecting because the new T3i and conversion would probably be about $600+

I'm going to investigate further. If the Rokinon produces an image quality at least as good as the Opteka does on the crop, that will be the one. Again, thanks.

Picture North Carolina wrote in post #17816606
Jeffrey,

Thank you very much. The amazon price on the sigma is $559, and the rokinon is $379. Both in the ballpark I was expecting because the new T3i and conversion would probably be about $600+

I'm going to investigate further. If the Rokinon produces an image quality at least as good as the Opteka does on the crop, that will be the one. Again, thanks.

The Rokinon 12mm F2.8 fisheye for full frame at $379 new ($300ish used if you go that route) is optically very, very good. I'd go that way. It's better than the lens you were previously using.

Very best,

Excellent, excellent. Thanks to all for the help. This is what POTN is all about. I'm going to start shopping for the best Rokinon price.

... but ya' gotta love amazon.

A buyer gave the lens 1 star review with this comment:

"I just started to use this item and it doesn't have auto focus, the lens has to be set at a specific setting in order to work..."

The first reply was a simple 4-word comment:

"Are you Ken Rockwell?"

Laughed so hard I almost fell out of my chair. I guess only us photogs would understand that one. Again, thanks.

roflmao!