Pentax-A 645 55mm

pavpen · 07-04-2014, 09:36 PM

Hi guys. My question is for those who familiar with smc Pentax-A 645 55mm f2.8. I noticed that if I set f-ring to "A" position and then start to close diaphragm by moving the lever at the rear end of lens with my hand, approximately 1 mm before the lever stops the diaphragm leafs will stop moving. Is this normal? This functionality has surprised me because my smc Pentax-A 50mm f1.4 for 35mm camera does not behave like 645 A lens.
Cheers.

dugrant153 · 07-05-2014, 07:37 AM

Mine does the same but seems to be normal? When I try to push the lever through F2.8 to F22 (not on A), it closes slowly and doesn't stop until F22.

pavpen · 07-08-2014, 09:04 PM

Originally posted by dugrant153

Mine does the same but seems to be normal? When I try to push the lever through F2.8 to F22 (not on A), it closes slowly and doesn't stop until F22.

Thank you dugrant153. You gave me peace of mind. I thought I got defective copy.
Cheers.

07-04-2014, 09:36 PM	#1
pavpen Veteran Member Join Date: Sep 2012 Location: US Photos: Albums Posts: 381	Pentax-A 645 55mm Hi guys. My question is for those who familiar with smc Pentax-A 645 55mm f2.8. I noticed that if I set f-ring to "A" position and then start to close diaphragm by moving the lever at the rear end of lens with my hand, approximately 1 mm before the lever stops the diaphragm leafs will stop moving. Is this normal? This functionality has surprised me because my smc Pentax-A 50mm f1.4 for 35mm camera does not behave like 645 A lens. Cheers.

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07-05-2014, 07:37 AM	#2
dugrant153 Veteran Member Join Date: Oct 2007 Location: Vancouver, BC Photos: Gallery Posts: 1,059	Mine does the same but seems to be normal? When I try to push the lever through F2.8 to F22 (not on A), it closes slowly and doesn't stop until F22.

07-08-2014, 09:04 PM	#3
pavpen Veteran Member Join Date: Sep 2012 Location: US Photos: Albums Posts: 381 Original Poster	Originally posted by dugrant153 Mine does the same but seems to be normal? When I try to push the lever through F2.8 to F22 (not on A), it closes slowly and doesn't stop until F22. Thank you dugrant153. You gave me peace of mind. I thought I got defective copy. Cheers.

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