Since I’m always on the lookout for sharp and well-corrected lenses, APO if possible, over time I have kind of run out of lenses for the Nikon mount to find. I am sure there are some out there, but I don’t know where they are or can’t (or won’t) afford them. LOL.
Another approach is to find ways to enhance the APO lenses that I already have. Let’s take my old standby the Voigtlander 125mm f/2.5 APO Lanthar, still the best all-around macro lens that I know of. Other lenses best it in this or that feature, but when you add up all the features, the CV-125 still comes out on top every time.
One of the areas where the CV-125 didn’t quite match up to some of the best APO lenses is sharpness, whether you consider sharpness as acuity and resolution or, as I do, add to that how well corrected is the lens is for the various aberrations, etc.
Yet, lately I did find another way to better compensate for some areas that the CV-125 fell ever so slightly short. And that is by using the lens on an automatic focus rail. I use StackShot, but there are also others out there.
If I mount the CV-125 on the Nikon D850 on the StackShot auto-rail and set the step increment on the finer (shorter increment) side, the CV-125 very much benefits from regular short increment steps and focus stacking.
The net result is to bring out or compensate for the very slight lack of sharpness I see when I stack the CV-125 by hand by turning the focus ring of the lens directly.
My point is that using precise auto stacking brings out the sense of sharpness with this lens and I would imagine with any other lens.
Here is a photo taken with the Nikon D850 with the CV-125 lens mounted on the StackShot auto-rail. To my eyes, the degree of refined sharpness is a little better than what I can do by hand. This image is reasonably sharp.
So, for we focus stackers out there, using auto-rails may be a way to get better “sharpness” without having to spend a fortune for better lenses. Of course, how would I know because I have spent way too much on buying really well-corrected lenses. LOL.
