Fisheye Image Quality: Improves with Price?

Question

Using a little Opteka fish attachment, I've gotten some very cool shots. The problem is that all shots get, of course, progressively less sharp as you move out from the center. I know that this is to be expected, especially with fisheye lenses and wide apertures. However, the blur is so bad that any photo taken with the attachment is completely unsuitable for printing.

So, here's the question: If I go buy a Canon/Sigma dedicated fisheye lens, how much better will the quality be? Worth the (steepish) price?

Thanks!

Answer 1

Adding an additional piece of glass to an already complex arrangement of elements is, at the very basic level, something that can degrade the performance of the lens. Adding one that is designed to optically alter the lens raises even greater risk, this is, after all, not explicitly designed to work with the lens. On that basis, you're already in the optical "hole" here as it were.

A dedicated fisheye lens is specifically designed to be such a lens and the combination of optical elements are there to handle the result of that. So, even the cheaper end of the fisheye lens options is very likely to perform better than your current combination. A better grade of lens is just going to be better in result. The same holds true for macro attachments and other forms of front or rear element items designed to change the essential optical properties of the lens.

Answer 2

Um... yes. You're comparing a cheap (a quick Google search shows around $35) aftermarket attachment to a dedicated lens from a major manufacturer. Lenses are very often "you get what you pay for" but you're not even talking about the same category of glass here.

Any fisheye lens from Canon/Sigma is going to give you vastly better results.