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rdeloe · 07-12-2020, 11:12 AM

Do you own a Pentax 645 Helicoid Extension Tube? If so, can you quickly measure something for me?

From the front, what is the diameter of the inner "throat"?

Thanks,
Rob

kayakfari · 07-12-2020, 07:06 PM

Quick check with a tape measure yields 45mm ID.

rdeloe · 07-13-2020, 05:36 AM

Originally posted by kayakfari

Quick check with a tape measure yields 45mm ID.

Thanks so much for checking.

So close! A few more mm and I would have been in business. Ah well, good to know.

kayakfari · 07-14-2020, 03:37 PM

Sure thing! What are you adapting?

07-12-2020, 11:12 AM	#1
rdeloe Forum Member Join Date: Aug 2015 Posts: 62	Pentax 645 Helicoid Extension Tube inner diameter Do you own a Pentax 645 Helicoid Extension Tube? If so, can you quickly measure something for me? From the front, what is the diameter of the inner "throat"? Thanks, Rob

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07-12-2020, 07:06 PM	#2
kayakfari Senior Member Join Date: Oct 2016 Location: South Florida Posts: 173	Quick check with a tape measure yields 45mm ID.

07-13-2020, 05:36 AM	#3
rdeloe Forum Member Join Date: Aug 2015 Posts: 62 Original Poster	Originally posted by kayakfari Quick check with a tape measure yields 45mm ID. Thanks so much for checking. So close! A few more mm and I would have been in business. Ah well, good to know.

07-14-2020, 03:37 PM	#4
kayakfari Senior Member Join Date: Oct 2016 Location: South Florida Posts: 173	Sure thing! What are you adapting?

Pentax 645 Helicoid Extension Tube inner diameter

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