Pentax 67 lenses on Pentax 645?

Has anyone tried using the P67 lenses on the Pentax 645 via the adapter? What are the upsides and downsides to this (aside from the weight of the larger format lenses and not being able to utilize some of the autometering functions on the 645)? I have a full range of 6x7 lenses and was thinking about a smaller, more portable format to maybe replace 35mm.

Thanks in advance,

Charles

One advantage in using the 67 lenses on the 645 is that you will not

be using the entire image circle available with these lenses. This

fact will benefit sharpness. You could probably shoot the lenses wide

open without the image degradation when these same lenses were used on

a 67.

I have been using a 300/4 SMC Takumar on my Pentax 645 for a couple of years and have been very satisfied. However, I also just bought the 300/4 ED-IF for the 645. I will try to do a test before selling the Takumar. As far as dimensions and weight, there is very little difference between the 6X7 and 645 300mm lens.

P645 93mm x 208mm at 1360 g.

P6X7 92.5mm x 186mm at 1430 g.

Also, I just noticed this after having a the P6X7 to P645 adapter for a couple of years, the adapter has an outer bayonet thread so I guess any of the long telephotos can be used on the P645.

I have for several years been using two 645's (old type) with adapters

mounted on the following 67 lenses: 400mm IFED, 135mm, 105mm, 55mm -

and found that the combination works fine - I have the impression

that it works optically better or same level, than corrosponding

native 645 lenses (especialy the 135 and the 400 combination is fine -

the 67/400mm ifed seems even sharper than my 645/600 mm ifed).

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The combination 645/67lensadapter allow you to work fast with

motorwinder, but without adding a new set of lenses in your bag

I use the Pentax 6x7 120mm Soft lens on my 645 via the Pentax

adapter. Great for bride and groom portraits- variable soft focus,

nice focal length, close focusing lens.

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Now if I could only use this lens on my Nikons.....

Greg: Using and adapter (http://www.zoerk.com/pages/p_mounta.htm) you

can use your Pentax 67 lenses on your Nikon.

Question:

The idea of using 67 lenses on the 634 Pentax is intriguing.

Can anyone tell me how the focal length of 67 lenses convert to the

645 system? How long would the 67 400 be on the 645 camera? or would

it just be the same focal length on a smaller format? Also, what

metering would be lost on the 645 system with a 67 converter?

thanks mark smith

Mark,

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Have a look at my article which answers all of these questions at...

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http://www.luminous-landscape.com/645nii.htm

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Michael