[Yamanobori]

If you want to get 5x magnification, you simply need to create an extension 6x the focal length. For a 105mm lens, you simply need 630mm between the lens and the image plane. For a 200mm lens, you need 1200mm between the lens and the image plane.

M = (d – ƒ) / ƒ where d is the lens to image plane distance.

This is really why microscopes are so popular for imaging.

[Josias]

Sounds good! I am getting the bellows - so I can combine with the 200 or 105 plus extension tubes - should do the job...

[desertscape]

Klaus, I'm doubtful that the formula in question works for the 35mm fisheye since this lens has unequal image magnification across the frame. Paraxial areas have higher magnification than the marginal areas. Pentax does not list the Fisheye in their Extension Tube/Close up booklet-probably for this reason.

[klaus123]

Klaus, I'm doubtful that the formula in question works for the 35mm fisheye since this lens has unequal image magnification across the frame. Paraxial areas have higher magnification than the marginal areas. Pentax does not list the Fisheye in their Extension Tube/Close up booklet-probably for this reason.

I tried it (just in the view finder): The focal distance with all 3 distance rings is exactly at the front lens - on a K7 with adaptor that means, that one of the forum smileys is a full screen picture (~ 3:1)

[Josias]

So..., I upgraded and now I am where I wanted to be with magnification, for now at least... - It's a serious pain to take a Photo (highest magnification)..., will post the outcome. Anyways, it's a felxible setup!

[Josias]

I tried it (just in the view finder): The focal distance with all 3 distance rings is exactly at the front lens - on a K7 with adaptor that means, that one of the forum smileys is a full screen picture (~ 3:1)

With full magnification I get the smiley in full frame... Is there any way to just take it times four (~12:1) - compared to small format? I am really not up for crunching numbers (formula)...

[Nass]

Good grief