Tagged Questions
6
votes
1answer
202 views
When focusing at max zoom, focus is lost after zooming out. Is that normal?
On my Canon kit lens, I could completely zoom in, focus on the object and then zoom out to take the picture with the object still in focus.
Now I have a Sigma 18-200mm (with a Canon 600D) and that ...
4
votes
1answer
167 views
Do all telephoto zoom lenses backfocus on the wide angle end?
I’ve just gone through a round of testing with two telephoto zooms, on two different cameras, and both appear to have significant back focus issues at the 70mm end.
I just had the Nikon 70-200 f/2.8 ...
7
votes
1answer
363 views
Why is the Canon MP-E 65mm F/2.8 Macro Lens not called a zoom?
The Canon MP-E 65mm works differently than my other macro lenses. Compare:
With a standard 35mm macro, I can frame first and then adjust focus which only changes framing very slightly with.
With the ...
3
votes
3answers
2k views
What is the technical difference between focus and zooming?
This may look like a silly question but I don't know what the difference between zooming and focusing is. Zooming in will usually let me have fewer subjects in the scene while zooming out will allow ...
4
votes
2answers
687 views
Is it normal for focal length to change while focusing?
When I change the focus distance on my Pentax 55-300mm lens, the focal length appears to change. More specifically, the lens appears to zoom in as I focus towards the minimum focusing distance. This ...
6
votes
5answers
1k views
Why is my Nikon 18-200 lens not focusing at higher focal lengths?
My Nikon 18-200 lens on a D300 camera will not focus when it is zoomed between 135mm and 200mm. Is there any tips on how to solve this besides handing it in to a photo store?
11
votes
3answers
2k views
How does changing focal length affect depth of field?
I'm curious about how my "area of acceptable focus" changes when the focal length of the lens I'm using changes as I zoom (or switch lenses). In particular, I'd like to know how the front & back ...
