Do we still need a TC?

Started 10 months ago | Discussions thread
Anastigmat
Forum ProPosts: 12,593
Like?
Re: Do we still need a TC?
In reply to Mark Ransom, 10 months ago

Mark Ransom wrote:

A teleconverter works by magnifying the image that it gets from the primary lens. You could get the same effect by simply cropping, but the assumption is that the magnified image will be higher in quality than the cropped image. For a high-quality primary lens coupled with a decent teleconverter this has been the case until now. But with the introduction of the K-3 at 24MP with no anti-alias, have we reached the point where cropping can do just as good a job?

I'd love to hear from someone with both the K-3 and a decent TC to do a direct comparison.

Packing more pixels onto the same sized sensor does not actually give you higher resolution. It just gives you larger files. How much resolution you get depend on how good your lens is, and also on diffraction. If you stop down your lens to f/11 or smaller, your resolution is limited to a few megapixels even if you have a super duper lens that can resolve over 100 line pairs per mm. Resolution aside, the greatest obstacle to sharp images when using teleconverters and long lenses is focusing accuracy. If your lens is f/5.6, a 2x teleconverter requires manual focusing, Unless you focus correctly, you won't get a sharp image.

Reply   Reply with quote   Complain
Post (hide subjects)Posted by
Keyboard shortcuts:
FForum PPrevious NNext WNext unread UUpvote SSubscribe RReply QQuote BBookmark post MMy threads
Color scheme? Blue / Yellow