i'm not familiar with an achromatic lens. is this the same as a close-up filter?
Yes, and no.
The close-up filter (#1 - #10) is a single element lens, whereas the Achromatic lens is at least 2 elements.
When I started photographing 40+ years ago, the single element lens was pretty bad, susceptible to chromatic aberration and other things. The 2 element Achromatic lens is designed to prevent that, and is usually sharper at the edges.
It's possible that technology has improved things, and you will have research the topic and test for yourself.
i also see that they have different lens numbers or strengths (like #1 - #10). which one did you use and which one would be good for a 12-35 f/2.8 lumix lens?
I didn't use that type of close up lens, rather, a Nikon 6T Achromatic lens.
I assume you are thinking of increasing magnification, since the 12-35 mm already has a close working distance of about 5."
One problem with short focal lengths for closeup work is that you get closer as the magnification increases, which is annoying if you use flash, or get too close to insects and frighten them.
Here is a quick test using the 12-35mm @ 35mm (=70mm):
[ATTACH alt="Working distance is about 5" @70mm"]1325125[/ATTACH]
Working distance is about 5" @70mm
[ATTACH alt="Working distance is about 3" @70mm + Nikon 6T 2.9 diopter Achromatic lens"]1325126[/ATTACH]
Working distance is about 3" @70mm + Nikon 6T 2.9 diopter Achromatic lens
Also, the magnification isn't that much with a short focal length lens. You could get a higher strength lens, of course. Strength is measured in diopters.
Again, you will have to research to see what magnifications/working distances are possible with the 12-35 mm
regards,
- Richard
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