The fantastic 2018 PF T-shirts are now available!

Aboudd · 06-14-2011, 04:43 PM

Originally posted by Digitalis

no on a 24X36mm sensor the Pentax 150-300mm f/5.6 @ 300mm it will behave like a 300mm lens, a slow 300mm lens.

In other word,it's roughly 80% of the length to equal a FF 35mm perspective on the 645 D

jwjohnson · 06-14-2011, 04:49 PM

The crop factor is around .75 - .80 relative to FF 35mm depending on if you are concerned about horizontal or vertical size since the form factor is different. The 300 would behave as a 300 on a full frame 35mm camera, but putting it on the 645D would give you the equivalent of about the 234mm on FF 35mm.

Thread Tools	Search this Thread
Show Printable Version E-mail to a Friend	Search this Thread: Advanced Search

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
Crop factor	cjbroadwell	Troubleshooting and Beginner Help	9	01-01-2011 08:52 AM
crop factor again!!	adwb	Photographic Technique	7	12-04-2010 06:56 PM
compensating for crop factor	jeans	Pentax DSLR Discussion	52	01-28-2010 03:03 PM
Aperture x Crop Factor	BBear	Photographic Technique	24	07-03-2008 08:54 PM
Crop Factor	Wheatfield	Pentax DSLR Discussion	32	06-28-2008 01:20 AM

06-14-2011, 04:43 PM	#16
Aboudd Senior Member Join Date: Jun 2011 Location: Arlington, VA Posts: 187	Originally posted by Digitalis no on a 24X36mm sensor the Pentax 150-300mm f/5.6 @ 300mm it will behave like a 300mm lens, a slow 300mm lens. In other word,it's roughly 80% of the length to equal a FF 35mm perspective on the 645 D

06-14-2011, 04:49 PM	#17
jwjohnson Junior Member Join Date: Jan 2011 Location: United States Posts: 36	The crop factor is around .75 - .80 relative to FF 35mm depending on if you are concerned about horizontal or vertical size since the form factor is different. The 300 would behave as a 300 on a full frame 35mm camera, but putting it on the 645D would give you the equivalent of about the 234mm on FF 35mm.

Crop factor of the 645d

The fantastic 2018 PF T-shirts are now available!