Medium Format Family

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Extension tubes

bob_crane

New Member
Hi all,
I was wondering if anyone could give me advice on which extension tubes to purchase to give me the most amount of flexibility with an 80mm Planar. I will be photographing some religious artifacts of various sizes and unfortunately I can't afford a 120mm Makro Planar. I've used one before on rental and I loved it, but the local store doesn't carry rentals anymore. I figured tubes are the most cost effective way to go especially since I'm not getting paid for this project.

I have the Close Up Photography PDF from Hasselblad, but I'm looking more for personal experiences and advice.
Thanks in advance,
Ara
 

qnu

Banned
Ara,

The most flexible you are with as many tubes as possible.
The 80 mm lens has a built in extension of about 10 mm.
To get a seamless coverage, the first tube should be the 8 mm. Then you step up a ring, in multiples of 8 (16, 32, 56, then the bellows).

But the size of the field you need to cover dictates what extension you need:

extension = (56.5 mm / field of view) * focal length.

So if you, for instance, need to fill the frame with something 30 cm in size, the extension you need is:

(56.5 / 300) * 80 = 15 mm

That's more than the lens itself can provide, so you need the 8 mm tube, plus a bit from the lens.

The 80 mm lens performs very good in the close-up range. No problem there.
 
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