Hi Nick,Thought I'd chime in as I've used both the MPE and this new 25mm handheld in the field before.
Regarding diffraction, it really depends on your personal level of tolerance.
I've tried both lenses at 5x at F/8. The diffraction was not acceptable to me, although to others it could be perfectly fine.
At F/5.6, diffraction was much lesser, although DOF is also noticeably thinner, such that I get more out of focus shots.
The obvious advantage of this lens is the size, which MPE cannot compete on. Smaller size means easier to find the subject in your frame, easier to get the angle you want, and easier to light up the subject.
The disadvantage is the loss of light and precision when focusing since the aperture is in front of the lens, making it physically impossible (probably) for aperture coupling. BUT, this can still be overcome with some practice.
Here's a shot using the 25mm at 5x on a full frame sensor at F/5.6, lightly cropped. Spider is almost 2mm across.
I noticed you will be evaluating the new Laowa 25mm Macro as well as Keith. This is a particularly interesting lens for folks with a Nikon base I would think, since we can't use the superb Canon MP-E 65 and Nikon has nothing like the MP-E 65.
There's an interesting comment by Rik here regarding focal length and DoF on the Laowa 25mm evaluation thread.
https://www.photomacrography.net/forum/viewtopic.php?t=36410
This seems to follow my experience and lens theory.
DoF = Lambda/(2(1-root(1-NA^2))) ~ Lambda/(NA^2) for small NA, although I often use an augmented form that takes into account the sensor pixel size and adds Pixel Width/(M*NA).
Curious to what you and Keith think, and looking forward to both of your reviews.
Hint: Please show some fixed subjects (hopefully I won't get bashed for asking)!
Best,
--
~Mike~
Hey Mike,
Sorry for the late reply as I don't frequent the forum much.
I usually don't really go down to the technical details, and just concentrate on shooting.
On fixed subjects, I did try deep stacks on cryptic spiders that stood still enough for over 10 minutes, and with extension tubes to push the magnification up to 9.1x. Not very good yet as the spiders tend to twitch a little even though they look like they are stationary.
and much easier to light the subject.
