Bower 85mm f1.4 doesn't report focal length

ChopperCharles · 06-13-2013, 12:44 PM

It has electrical contacts, and it works in the A setting... but why doesn't it report the focal length? Did I get a dud, or is this how it's supposed to be?

Charles.

Adam · 06-13-2013, 12:59 PM

Originally posted by ChopperCharles

It has electrical contacts, and it works in the A setting... but why doesn't it report the focal length? Did I get a dud, or is this how it's supposed to be?

Charles.

Since the lens has no built-in electronics, it can't transmit this data to the camera. You have to set the FL manually.

**kiwi_jono** · 06-13-2013, 01:37 PM

The good news is that the camera will remember the last manually set FL - so you only have to set it once (until you fit another manual lens).

Its a wonderful lens BTW - enjoy!

**THoog** · 06-13-2013, 05:09 PM

The electrical contacts on A-series lenses only tell the body the range of apertures that the lens supports - three bits for widest aperture, three for narrowest aperture, and a retractable pin to tell the body that the aperture ring is the 'A' position. It's early-1980s technology (when an 8-bit microprocessor was the size of your thumb), but it was fairly bulletproof.

The F-series lenses added a "digital info" pin, which allowed electronics in the lens to transmit a lot more information to the body - focal length, lens identifier, etc.

06-13-2013, 12:44 PM	#1
ChopperCharles Veteran Member Join Date: Jan 2010 Location: Durham, nc Photos: Albums Posts: 953	Bower 85mm f1.4 doesn't report focal length It has electrical contacts, and it works in the A setting... but why doesn't it report the focal length? Did I get a dud, or is this how it's supposed to be? Charles.

06-13-2013, 12:59 PM	#2
Adam Administrator Site Webmaster Join Date: Sep 2006 Location: Arizona Photos: Gallery \| Albums Posts: 51,594	Originally posted by ChopperCharles It has electrical contacts, and it works in the A setting... but why doesn't it report the focal length? Did I get a dud, or is this how it's supposed to be? Charles. Since the lens has no built-in electronics, it can't transmit this data to the camera. You have to set the FL manually. Adam PentaxForums.com Webmaster (Site Usage Guide \| Site Help \| My Photography) PentaxForums.com server and development costs are user-supported. You can help cover these costs by donating or purchasing one of our Pentax eBooks. Or, buy your photo gear from our affiliates, Adorama, B&H Photo, KEH, or Topaz Labs, and get FREE Marketplace access - click here to see how! Trusted Pentax retailers:

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06-13-2013, 01:37 PM	#3
kiwi_jono Loyal Site Supporter Join Date: Dec 2009 Location: Christchurch, New Zealand Photos: Gallery \| Albums Posts: 2,437	The good news is that the camera will remember the last manually set FL - so you only have to set it once (until you fit another manual lens). Its a wonderful lens BTW - enjoy!

06-13-2013, 05:09 PM	#4
THoog Loyal Site Supporter Join Date: Aug 2012 Location: North Carolina Photos: Gallery \| Albums Posts: 3,685	The electrical contacts on A-series lenses only tell the body the range of apertures that the lens supports - three bits for widest aperture, three for narrowest aperture, and a retractable pin to tell the body that the aperture ring is the 'A' position. It's early-1980s technology (when an 8-bit microprocessor was the size of your thumb), but it was fairly bulletproof. The F-series lenses added a "digital info" pin, which allowed electronics in the lens to transmit a lot more information to the body - focal length, lens identifier, etc.

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