Opteka Fisheye Adapters question

divamum

(whoops - if a mod reads this, can you correct the subject line to "fisheyE". Typing too fast.....)

I want to play around with a fisheye for something coming up. I found these which, from the reviews, seem to be a reasonable low cost product for what I have in mind.

I'm unclear on the difference between the .20 fisheye and .35 fisheye/macro, and can't find enough images to figure out how they alter the image.

Also, I would ideally want to use something like this on my widest lens, which is the Tamron 17-50... which has a 67mm filter ring size. The lens itself comes with adapters, but the largest appears to be a 58mm. Would it actually work on a larger lens, or would an additional step-up adapter cause problems? I have a 50 1.4, but seems to me I wouldn't get enough distortion using that on a crop camera. :dunno

Can anybody enlighten me? Thanks in advance!

Toshido

Diva, today is kinda busy but if I have time tonight I will mount my set on my 50mm f/1.4 for some test shots.

I picked up a wide angle (not fisheye) and a teleconverter set really cheap from e-bay for use on my powershot s3 IS. They should fit my 50mm.

Might give you an idea.

I have not used them since I bought my Rebel XT 2 years ago and even then I thought they degraded image too much. The wide angle and macro was not too bad, the teleconverter was useless though.

craig_d

I don't recommend fisheye or macro adapters. I've yet to see one that doesn't degrade images unacceptably. (And the word "Opteka" apparently means "junk" in some foreign language.) A real fisheye is the way to go, and they aren't all that expensive because with a fisheye you don't have to correct the wide-angle lens's natural tendency toward barrel distortion. Fisheye lenses are all about barrel distortion!

Divamum, for a fisheye, you are at a disadvantage because you shoot a 1.6x camera. Most fisheye lenses are designed for full-frame and you lose the best (most distorted) part of the fisheye effect if it gets cropped off by a smaller sensor.

Your best bet, I think, is to get an 8mm circular fisheye, which on 1.6x will behave more like a diagonal fisheye (though with some vignetting in the corners). Sigma makes one for Canon EF mount, though I don't know how good it is. Tokina also has a rather unusual 10-17mm fisheye zoom lens; I'm not sure how that would behave on APS-C, or how good it is. It might be worth looking into.

Some (such as the admired-by-some-loathed-by-others Ken Rockwell) say that the best fisheye lens for any 35mm SLR is the Canon EF 15mm f/2.8 Fisheye (full-frame), which I own and love. It typically costs around $650 new. You can see a few shots I've taken with it on my 5D2 here:

http://craigd.smugmug.com/keyword/canon ef 15 f2pt8 fisheye

divamum

Thanks, both.

Toshido, that would be fabulous if you could share some images with the attachement - I'd really appreciate it

Craig, LOVE the shots you linked -thanks! While I take your point and certainly wouldn't be expecting much from one of these, the add-on is $30 which, for an effect which is going to be "just for fun", is a whole lot more affordable than a $650 lens (even used) is going to be I wish I had the $ to invest in a "real" one!

My first thought for a fish was to go with a Lensbaby, but I would want the Composer and by the time you add it all up with the extra optics it's nearly $400, so I've pretty much abandoned that idea for now. I don't want one of the manual-only Samyang/Vivitar/Etc lenses because I struggle to focus manually, especially if I have to do it fast.

Which leads me back to the adapter.... I was even thinking that if I like the effect it gives (and, again, I'm not necessarily looking for a supersharp "real" fisheye, more of an artistic effect) I could pick up a cheap 18-55 kit lens from somewhere and add it to that since it has the smaller filter size than my Tam. Instant fishy fun for under $100.

What I'm still trying to figure out is the .20x vs .35x - is it a multiplication factor, thus the 20x is wider?

pyry

divamum wrote:

My first thought for a fish was to go with a Lensbaby, but I would want the Composer and by the time you add it all up with the extra optics it's nearly $400, so I've pretty much abandoned that idea for now. I don't want one of the manual-only Samyang/Vivitar/Etc lenses because I struggle to focus manually, especially if I have to do it fast.

What I'm still trying to figure out is the .20x vs .35x - is it a multiplication factor, thus the 20x is wider?

You don't have to focus a fisheye at all. You set to infinity and everything from three feet onwards falls into focus. I'm about this >< close to getting the Samyang 8mm myself.

The .20x etc are multiplication factors indeed.

craig_d

divamum wrote:

What I'm still trying to figure out is the .20x vs .35x - is it a multiplication factor, thus the 20x is wider?

No, I think it's a magnification factor, so the .20x has a smaller image circle, not a wider field of view. Unfortunately, even Opteka's web site is not particularly helpful about the differences between the two models. I did find a comment on another forum saying that the .35x's image circle does not fit entirely within the frame even when zoomed out, while the .20x's does. I can't vouch for that, however.

As pyry noted, manual focus with a fisheye (or any ultra-wide lens) is trivial, at least, it's trivial most of the time. The exception arises when your field of view includes something very close to the lens, but even then it's not that hard to deal with. MFD on the EF 15mm fisheye is 0.2m (about 8"), so there are times when simply setting focus to infinity won't do.

I've had it in mind for a while to get a Lensbaby too (other things keep taking priority). I agree with you that the Composer is the one to get. I don't think of the Lensbaby as an alternative to a fisheye, a tilt/shift, or any other special-use lens -- it's really it's own unique thing.

If an adapter is as cheap as you say, then I suppose you can't really go too far wrong with it. Even if it's useless, you have at least benefited from learning first-hand that it's useless. And if it turns out to have worthwhile applications, more power to you!

divamum

Yes, the .35 is $30, and the .20 is $60.

Regarding the all-manual aka Samyan - how do you meter for it? Do you get any kind of ttl metering, or do you have to resort to guesswork?

craig_d

divamum wrote:

Regarding the all-manual aka Samyan - how do you meter for it? Do you get any kind of ttl metering, or do you have to resort to guesswork?

You'd have to experiment to see what works. Aperture priority mode may work. Spot or center-weighted metering may work better than evaluative. Otherwise, fall back to full manual mode and either get proficient with the Zone System or use the successive approximation method (that is, guess, take a shot, look at the histogram, adjust, take another shot, repeat until satisfied).

Toshido

Did some tests here are some of the photos.

Did these on manual with the flash set to manual as well so you can see any effect on light as well. So far just a "real world" example and 100% crops from the middle of the frame. All test shots will be uploaded but will take a while to finish.

"Real world" example had some quick post done on it including sharpening. All others ran through Lightroom to convert to jpeg with no work done on them, then PS just for the 100% crop. Camera was tripod mounted and did not move.

Overall I was surprised at the quality I got. I am thinking the quality of the 50mm with 2x is actually sharper than my 70-200 2.8L IS... Of course I stepped these down considerably and think I need to test that claim soon.
If not for my 17-40 f/4L and the 70-200 f/2.8L IS I am thinking I might actually be willing to use these adapters.
My wide angle adapter comes apart an you can use one part as a macro adapter. My test shots are miserable, but I think it is equal blame operator and adapter. Definitely something for me to play with though.

Just click on a photo to go to my gallery with all the shots in it.

Real world sample with 2x converter on it. Also my favourite, he LOVES the flash and camera


100% crop from above.


50mm f/1.4 control


50mm with 2x converter shot at 100%


50mm with 0.5x wide angle converter


50mm at MFD with no adapters (handheld, TTL flash)


50mm with macro adapter (handheld, TTL flash)

Toshido

Slightly better example pf the macro lens.... Again still on the 50mm.

pyry

divamum wrote:

Yes, the .35 is $30, and the .20 is $60.

Regarding the all-manual aka Samyan - how do you meter for it? Do you get any kind of ttl metering, or do you have to resort to guesswork?

You get stop-down metering. The camera doesn't really know the lens is there (reading f/00), but it can measure the incoming light and with that it'll give you a shutter speed.

Try it, take the lens off the camera, put it in Av and meter.

divamum

Thanks Pyry for the metering clarification, and thanks Toshi for posting those! The quality is definitely better than I was expected, and for the low investment, it seems a no-brainer to give them a try.

Next question: I want to put the 58mm lens attachment onto a lens with a 67mm filter. Do I want a step up ring, or a step down ring (I can never remember which way it goes!)

pyry

divamum wrote:

Thanks Pyry for the metering clarification, and thanks Toshi for posting those! The quality is definitely better than I was expected, and for the low investment, it seems a no-brainer to give them a try.

Next question: I want to put the 58mm lens attachment onto a lens with a 67mm filter. Do I want a step up ring, or a step down ring (I can never remember which way it goes!)

67 to 58 is step down. Original to new size.