nikonians

Even though we ARE Nikon lovers,we are NOT affiliated with Nikon Corp. in any way.

| |
Go to a  "printer friendly" view of this message which allow an easy print Printer-friendly copy Go to the page which allows you to send this topic link and a message to a friend Email this topic to a friend
Forums Lobby GET TO KNOW YOUR CAMERA & MASTER IT Nikon D5300/D5200/D5100/D5000/D3300/D3200/D3100/D3000 (Public) topic #6560
View in linear mode

Subject: "RE: Where is the focus?" Previous topic | Next topic
gkaiseril Gold Member Nikonian since 28th Oct 2005Fri 24-Aug-12 04:00 PM
6739 posts Share on Facebook Share on Twitter Share on Linkedin    Click to send email to this author Click to send private message to this authorClick to view this author's profile
#9. "RE: Where is the focus?"
In response to In response to 5


Chicago, US
          

Maybe we need to step back to some very basic concepts.

A Prime lens is a fixed focal length lens and is optimized for sharp focus, corona aberration, and other lens properties.

A Zoom lens tries to cover a number of various focal lengths and has a sweet focal length for which the majority of lens properties are optimized and only acceptable at other focal lengths.

If you want to shoot Macro, it is best to use a prime lens designed for macro work. If you must use a zoom lens, then find the best focal length for that lens and use that length. So setting the focal length to the largest or smallest value may put your lens at the end of the reasonable results.

Focusing in a Macro mode is different than in the macro mode. In the Macro mode the lens focal length determines the magnification and the camera to object adjust the focus. That is why there are focus rails for serious macro shooters. You might want to switch to manual focus.

Another point to consider is that Macro images are magnified from the Macro image and camera shake, mirror slap, or any camera movement is magnified. So you either need a very good tripod and remove all sources of movement or have a very good VR lens and very good hand holding technique along with breath control.

If you look at the meta data for images shot with a prime lens you will see a tag for the "Effective focal length" as well as the "focal length". If you put a 50nn focal length lens on a D4 the values for these tags will be the same. If you put that same 50mm lens on your D5100, the focal length will be 50mm but the effective focal length will be 75mm. If you were to look through the viewfinder, you would see that the D5100 showed less of the scene than the D4 would show. And the amount less would be more than the 5% difference in the viewfinder. See "Field of View Values for Common Focal Lengths" And if you printed the captured images you would see that the D5100 only captured the 50% center section of the D4 image. The effective focal length is a means of comparing a 35mm size sensor to a different sized sensor for the users of 35mm film cameras. And since the original digital cameras had a sensor smaller than the 35mm cameras, it was referred to as the "crop factior".

George
My Nikonian Galleries

  

Alert Printer-friendly copy | Reply | Reply with quote

A general, generic topicWhere is the focus? [View all] , grnzbra Silver Member, Tue 21-Aug-12 01:22 PM
 
Subject Author Message Date ID
Reply message RE: Where is the focus?
JosephK Silver Member Fellow Ribbon awarded for his excellent and frequent contributions and sharing his in-depth knowledge and experience with the community in the Nikonians spirit.
21st Aug 2012
1
Reply message RE: Where is the focus?
gkaiseril Gold Member
21st Aug 2012
2
Reply message RE: Where is the focus?
grnzbra Silver Member
23rd Aug 2012
3
     Reply message RE: Where is the focus?
gkaiseril Gold Member
23rd Aug 2012
4
     Reply message RE: Where is the focus?
grnzbra Silver Member
23rd Aug 2012
5
          Reply message RE: Where is the focus?
Skyco Silver Member
24th Aug 2012
6
          Reply message RE: Where is the focus?
grnzbra Silver Member
25th Aug 2012
10
               Reply message RE: Where is the focus?
Skyco Silver Member
26th Aug 2012
11
          Reply message RE: Where is the focus?
pjonesCET Gold Member
24th Aug 2012
8
          Reply message RE: Where is the focus?
gkaiseril Gold Member
24th Aug 2012
9
     Reply message RE: Where is the focus?
pjonesCET Gold Member
24th Aug 2012
7
          Reply message RE: Where is the focus?
Stonecherub Silver Member
26th Aug 2012
12
               Reply message RE: Where is the focus?
gkaiseril Gold Member
26th Aug 2012
13
                    Reply message RE: Where is the focus?
grnzbra Silver Member
27th Aug 2012
14

Forums Lobby GET TO KNOW YOUR CAMERA & MASTER IT Nikon D5300/D5200/D5100/D5000/D3300/D3200/D3100/D3000 (Public) topic #6560 Previous topic | Next topic