Correct focal length when asked by K3

bscott · 06-22-2017, 07:27 AM

I have a Pentax K3 and I put a non Pentax teleconverter on the camera with a non Pentax lens the camera asked for the lens focal length. Do I select the lens actual focal length of the lens or the focal length resulting from using the teleconverter? Thanks

**Odinz** · 06-22-2017, 07:36 AM

I usually try to input a focal length that's close to the resulting lens+teleconverter

**jatrax** · 06-22-2017, 07:38 AM

The camera is asking in order to determine the focal length for shake reduction. It also has the side benefit of putting the focal length in the file EXIF of any pictures taken. You should use the actual focal length of the combination of TC and lens. So a 50mm lens + a 2x TC = 100mm on the camera.

Jens Lyn IV · 06-22-2017, 07:39 AM

You'll want the combined focal length of the two. That is, physical focal length of lens times teleconverter magnification. This mainly impacts shake reduction performance. If the focal length you need isn't listed, input the nearest shorter one.

Edit: congratulations to the two ninjas above me.

bscott · 06-22-2017, 07:59 AM

Thanks for your quick replies.

06-22-2017, 07:27 AM	#1
bscott Veteran Member Join Date: Oct 2013 Posts: 482	Correct focal length when asked by K3 I have a Pentax K3 and I put a non Pentax teleconverter on the camera with a non Pentax lens the camera asked for the lens focal length. Do I select the lens actual focal length of the lens or the focal length resulting from using the teleconverter? Thanks

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06-22-2017, 07:36 AM	#2
Odinz Loyal Site Supporter Join Date: Jan 2008 Location: Virginia, USA Photos: Albums Posts: 259	I usually try to input a focal length that's close to the resulting lens+teleconverter

06-22-2017, 07:38 AM	#3
jatrax Site Supporter Join Date: May 2010 Location: Washington Cascades Photos: Gallery \| Albums Posts: 12,991	The camera is asking in order to determine the focal length for shake reduction. It also has the side benefit of putting the focal length in the file EXIF of any pictures taken. You should use the actual focal length of the combination of TC and lens. So a 50mm lens + a 2x TC = 100mm on the camera.

06-22-2017, 07:39 AM	#4
Jens Lyn IV Senior Member Join Date: Jan 2014 Location: Ringsted, Denmark Photos: Albums Posts: 260	You'll want the combined focal length of the two. That is, physical focal length of lens times teleconverter magnification. This mainly impacts shake reduction performance. If the focal length you need isn't listed, input the nearest shorter one. Edit: congratulations to the two ninjas above me.

06-22-2017, 07:59 AM	#5
bscott Veteran Member Join Date: Oct 2013 Posts: 482 Original Poster	Thanks for your quick replies.