[Ilovemypentax]

Can a circular fisheye be adapted to a 645D?

I want the 180 degree circle and not a FF fisheye.

[Adam]

I'm not aware of any fisheye lenses for the 645D, there's one for the 6x7 system:
SMC Pentax 67 / Takumar 6x7 35mm F4.5 Fish Eye Reviews - 67 Wide-Angle Primes - Pentax Lens Reviews & Lens Database

It unfortunately wouldn't be that wide when adapted due to the 645D's crop factor.

[klaus123]

The shortest FishEye I know is the MC Arsat 30mm f/3.5 - but I never had one. For sure it will be far away from circular, but the price . if you find one is very afforable.

The 6x7-35mm-Fisheye is not that brilliant on my film-67(55x69) and would be cropped too much on a 44x33-Sensor.

The 35mm Fisheye and a result (The DA10-17 deals much better with flares!)

[hsteeves]

mamiya had a 24mm fisheye for their 645 but it was FF and not adaptable to the Pentax 645; l you could adapt 30mm Hasselblad fisheye but it too would be FF. I have not heard of a circular 180 fisheye for medium format.

[bull drinkwater]

my experiments have been with the bower 0.16 screw on aux lens. it has 58mm threads, so it screws into the 55 and the 75mm lenses. it needs a step up ring to fit the 45mm lens so far my results have been mixed, mostly undesirable. just for the fun of it I will keep experimenting . I also found an old unnamed 0.5 screw on lens, it widens the angle on the 45mm, but the edges are a little blurred. it's not enough to be a real wide angle and no way a fish-eye. if I ever get anything half decent, i'll i'll post some.

[FrankC]

The only solution I can think of is using a high-quality wide angle video lens converter. You'll probably need to start off with at least the 35mm lens and add on a .5x or .4x converter. But finding one with 82mm screw threads and will give good results is the tough part.

Both B&H and Adorama have a few to choose from:

Cavision 0.4x Fish-Eye Adapter for Lenses w/82mm Filter Threads LFA04X72HVXHD100

Cavision 0.5x Wide Angle Adapter Lens with 82mm Filter Thread #LWA05X86 LWA05X86

[bull drinkwater]

The only solution I can think of is using a high-quality wide angle video lens converter. You'll probably need to start off with at least the 35mm lens and add on a .5x or .4x converter. But finding one with 82mm screw threads and will give good results is the tough part.

Both B&H and Adorama have a few to choose from:

Cavision 0.4x Fish-Eye Adapter for Lenses w/82mm Filter Threads LFA04X72HVXHD100

Cavision 0.5x Wide Angle Adapter Lens with 82mm Filter Thread #LWA05X86 LWA05X86

there is one by Opteka that looks like it's twin , but my results so far have sucked. finding a step-down ring from 82mm to 58mm was not a problem. I may experiment again, but i'm not hopeful. OOPs almost forgot. mine required a adaptor with glass in it . for the results I am getting , it's a pain. if it ever works for me i'll share it.

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Last edited by bull drinkwater; 06-05-2014 at 03:10 PM. Reason: left something out

[bull drinkwater]

The only solution I can think of is using a high-quality wide angle video lens converter. You'll probably need to start off with at least the 35mm lens and add on a .5x or .4x converter. But finding one with 82mm screw threads and will give good results is the tough part.

Both B&H and Adorama have a few to choose from:

Cavision 0.4x Fish-Eye Adapter for Lenses w/82mm Filter Threads LFA04X72HVXHD100

Cavision 0.5x Wide Angle Adapter Lens with 82mm Filter Thread #LWA05X86 LWA05X86

I just spent some time experimenting, without an adaptor I couldn't even get it near to focusing.
even with the adaptor the results still sucked.

[bull drinkwater]

Can a circular fisheye be adapted to a 645D?

I want the 180 degree circle and not a FF fisheye.

I am using a 45mm lens, I have a bower .16 screw on lens and a .5 screw on that I got as a part of a kit. the .5 gives a wider angle. bower also has a .38x that might give a wider angle. the .16x gives a circular image. I shot apatures between f 13 and f 20. the lenses cost $35.00 plus the cost of a 67mm to 58mm step down ring. it works for me. number 2 was with the .03x not worth the bother. numember 1 was shot with the 45mm plus the .5x . I hope these samples give you some ideas photo number 1 is at least better than the $5000.00 alternative. at least to me.