lens test at 3.7x

[Barry]

I encountered some troubles with images not being crisp, but guess I now found the problem, since i noticed the fibre optic lightsource caused vibration (ventilator). I put the lightsource on an isolated plateau rather than on the same surface where the subject is, and it works.

A friend was so nice to loan me a lens so I could test 4 lenses: Macro Nikkor 12cm and 65mm, Luminar 63mm, and an S-Planar 74mm. The first 3 were shot at ap=1.5, the S-Planar on an indicated ap=11 (which is the effective aperature when shot at 1:1). Subject was the exuvia of spider fangs I found on the attic.

Shot at 3.7x, image was 6mm on sensor of Canon 50D. Crops of 800x800 pixels, stacks of 25 jpg images shot at 0,05mm, processed in Helicon Focus 5, no post-processing. Illuminated with fibre optic light, diffused through transparent paper. Unfortunately I had to change the light setup after I shot the Macro-Nikkor 12cm.
I found the Macro-Nikkor 12cm out of its range (it is very nice up to 2x). Winners were the 2 Zeiss lenses, there is practically no difference between them.

Cheers,
Barry

Macro-Nikkor 12cm:


Macro-Nikkor 65mm:


Luminar 63mm:


S-Planar 74mm:

[PaulFurman]

What are the optimal ranges for each of these? I see a steady improvement from top to bottom. Zoomed in & sharpened, there are differences, also the contrast improves working down the list.

[Barry]

The Macro-Nikkor I found best in the range 0,5x - 2x. The Luminar 63mm I found best at 2x-4x. This appears to be conform their documented optimal magnifications. I tried the Luminar also at higher magnifications, but diffraction was present.

I cannot tell the optimal ranges for the Macro-Nikkor 65mm and S-Planar 74mm yet, as this was the first test for those. The S-Planar is documented for 1:1 which is also indicated on the lens barrel. Thus I was pleasantly surprised with its performance at nearly 4x. Am curious about its performance at 1x and 2x.

Cheers,
Barry