24-70S f/4 focus ranges with extension tubes

Joined
May 5, 2005
Messages
22,164
Location
SW Virginia
Like some of the rest of you I bought a set of Meike extension tubes to use with my Z 6 and 24-70S. In actual use I have had trouble knowing where to place the subject in order to get good focus with these tubes. So today, with time on my hands, I decided to try to map it out. I put a ruler on a table and placed a good focus subject alongside it and measured the minimum and maximum distance that it would focus at 50mm and 70mm focal length.

I did this first naked, then with the 11mm tube, the 18mm tube, and both together (29mm). All distances were measured in inches from the front of the lens.

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I thought some of you might find this useful. I invite you to verify this for yourselves to check my work.

Incidentally, the second decimal place is not significant in each case.
 
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Joined
Sep 13, 2007
Messages
15,419
Location
Northern VA suburb of Washington, DC
On a related topic, I've recently learned after using my Z6 for about a month that when working with tabletop photography, focus peaking is not as accurate as I need it to be. My solution is to display the part of the scene I want to be in focus at 100% in the rear LCD. That method was always effective when using my DSLR and continues to be effective when using the Z6.
 
Joined
Sep 13, 2007
Messages
15,419
Location
Northern VA suburb of Washington, DC
Did either of you try setting a different colour for the Focus Peaking?

DG
I've used yellow mostly but switched to red when the colors in the scene made the red easier to see. I moved the focus ring slightly back and forth until settling on the position that rendered the densest focus peaking in the area I wanted to be in focus. This is with the scene displayed in the LCD at the default magnification. After releasing the shutter, the part I wanted in focus and had been indicated by the focus peaking to be in focus wasn't in focus.

Then I began magnifying the image in the LCD to at least 100% to manually set the focus. It worked every time.

As a reminder, my anecdotal testing is only in close-up photography, not macro photography or photography that is distant enough that I wouldn't consider it close-up photography. The focus peaking may be more accurate in other types of photography. My hunch is that it's no more accurate when doing macro photography because the depths of field are so small but that it's very accurate in non-close-up photography because the depths of field are considerably larger, thus allowing more margin for error.
 

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