Looking for a 50mm fisheye attachment...

[Dubsteez]

Hey guys,
I have been shooting with my grandfathers pentax 35mm a lot lately and I decided I want a wide angle for it. I have used those very inexpensive screw on attachments that you can screw on to a lens in the past, but I am having a hard time finding one to fit the pentax. It is a 50mm lens and I feel like i can only find 52 and 58mm lenses and step up rings. Is 50mm an odd size or something? Any suggestions? thanks in advance.

 

[TacotheTurtle]

Usually those 52mm screw ons will fit on a 50mm. I can fit my screw on 52mm lens hood on my 50mm.

 

[480sparky44 43]

I think your focal length is 50mm..... your filter size is something else.

 

[TacotheTurtle]

Yeah, not sure what he is really talking about. But I know the threading on my standard 15-88 52mm and 50mm f/1.8 are fairly similar and can share filters/hoods/attatchments.

 

[Dubsteez]

Woops, Sorry if i gave false info. this is the camera Honeywell Pentax H1a.
So after what i gathered from this i think i need a 46mm wide angle attachment, or a 55mm lens. Correct?

 

[Big Mike]

The camera doesn't matter....it's the lens and the size of the filter threads on the front of the lens. Look at the lens (probably the front) and look for the diameter symbol ⌀ and the number (size) next to it.

 

[480sparky44 43]

Focal length is an optical property of the lens.

Filter size is a physical measurement.... the diameter of the threads on the front edge of the lens.

Back in the old days, I had a 20mm, a 28mm, a 40mm, two 50mm and a 120mm focal length lenses. They all used 49mm filters.