New DA21: Advise on How to Test for BF/FF

[Sam]

I will be receiving a new DA21 this week.

Could you advise me on how to test for possible BF/FF issues when I receive it?
I remember Ben had to return a couple of copies of this lens.

Thanks in advance

Sam

[sft]

Take Pictures

Seriously though - just take normal shots and see if the focus point is indeed what you focused on - you'll notice if it is not focusing properly. Also older DA21's sometimes seem to act in a weird way - focus at f/3.2 and take the shot - then change aperture to something smaller than f/5.6 - say f/8 and half press and AF and without letting go of the half press & AF change aperture back to f/3.2 and take the shot. The sharpness should be the same in both the normal f/3.2 shot and the focused with f/8 but taken with f/3.2 shot. Mine is a newer batch and does not exhibit this or any other problem and I would expect yours to be fine as-well.

[Sam]

I will check it out as soon as I receive it.
Thank you!!


Sam

Originally Posted by sft

Take Pictures

Seriously though - just take normal shots and see if the focus point is indeed what you focused on - you'll notice if it is not focusing properly. Also older DA21's sometimes seem to act in a weird way - focus at f/3.2 and take the shot - then change aperture to something smaller than f/5.6 - say f/8 and half press and AF and without letting go of the half press & AF change aperture back to f/3.2 and take the shot. The sharpness should be the same in both the normal f/3.2 shot and the focused with f/8 but taken with f/3.2 shot. Mine is a newer batch and does not exhibit this or any other problem and I would expect yours to be fine as-well.

[Wethphotography]

If after taking photos you think you may have a problem, use this link to read about and print a chart to photograph. http://http://focustestchart.com/chart.html I have a lens that I noticed an issue on when I was using it wide open; I then confirmed it using this chart. I resorted to the chart and a tripod to be sure that it wasn't "user error". I also checked several other of my lenses at the same time. The differences in results definately confirmed my one lens had a BF issue.

[Wethphotography]

If after taking photos you think you may have a problem, use this link to read about and print a chart to photograph. http://http://focustestchart.com/chart.html I have a lens that I noticed an issue on when I was using it wide open; I then confirmed it using this chart. I resorted to the chart and a tripod to be sure that it wasn't "user error". I also checked several other of my lenses at the same time. The differences in results definately confirmed my one lens had a BF issue.

[Wethphotography]

If after making some photos you suspect an issue you might want to check out this site and use the chart to confirm http://http://focustestchart.com/chart.html