Search found 13 matches

by Doppelgänger
Fri Feb 16, 2018 11:52 am
Forum: Equipment Discussions
Topic: Laowa 25mm F/2.8 2.5x-5x ultra macro lens
Replies: 78
Views: 30640

LoCA decreases dramatically when the aperture is stopped down. Photographing these metallic objects and resolution charts really unfairly pushes the lens. These are situations most photographers will not find themselves in. The lens will be available after Chinese New Year, which is around the end ...
by Doppelgänger
Fri Feb 16, 2018 10:37 am
Forum: Equipment Discussions
Topic: Longitudinal Chromatic Aberration 1X Macro Lens Test
Replies: 42
Views: 7716

I have to respectfully disagree here; the opposite is true in my experience. You don't "program" anything when taking a bracketed image. Leave the camera always set to bracket. When you find a subject, press the shutter once and watch the magic happen. It is far faster than manually fiddling with a...
by Doppelgänger
Thu Feb 15, 2018 4:57 pm
Forum: Equipment Discussions
Topic: Longitudinal Chromatic Aberration 1X Macro Lens Test
Replies: 42
Views: 7716

Re: Longitudinal Chromatic Aberration 1X Macro Lens Test

The focus throw of the Voigtlander is very useful for manual focusing, but auto focus lenses have a distinct advantage in that focusing steps can be made very precisely via software and enable automation of the stack. Please refer to Rik's table below for some details. Bill Good point, if you're sh...
by Doppelgänger
Thu Feb 15, 2018 8:23 am
Forum: Equipment Discussions
Topic: Longitudinal Chromatic Aberration 1X Macro Lens Test
Replies: 42
Views: 7716

Robert did indicate that LoCA can be removed by stacking with Zerene (and presumably with other stacking algorithms), which is interesting and previously unknown to me. Since stacking is often used with higher magnification, LoCA is less problematic in this situation. One limitation of his test ser...
by Doppelgänger
Thu Feb 15, 2018 8:04 am
Forum: Equipment Discussions
Topic: Laowa 25mm F/2.8 2.5x-5x ultra macro lens
Replies: 78
Views: 30640

Thank you for your efforts and work in posting these findings. The 'horrible' CA is worrisome, but perhaps would be minimized with natural subjects, photographed with harmonious backgrounds, rather than 'edgy' subjects photographed against harsh backgrounds? I am still excited about this lens, but p...
by Doppelgänger
Thu Feb 15, 2018 7:59 am
Forum: Equipment Discussions
Topic: Longitudinal Chromatic Aberration 1X Macro Lens Test
Replies: 42
Views: 7716

Doppelganger, you've stated several times that CA can be corrected in post, while lack of sharpness cannot. However, the type of CA that Robert's tests were designed to reveal, LoCA, is not readily correctable in post. That's why Robert's tests here, which are aimed just at that aspect of the image...
by Doppelgänger
Thu Feb 15, 2018 7:52 am
Forum: Equipment Discussions
Topic: Longitudinal Chromatic Aberration 1X Macro Lens Test
Replies: 42
Views: 7716

Re: Longitudinal Chromatic Aberration 1X Macro Lens Test

One reason is that I do not shoot wide open. Also none of the lenses was sharpest wide-open. Thats enough reasons for me. You are welcome to run your own test for wide open sharpess, rendering and Bokeh. Be sure to share the results. It's true most lenses are not at their sharpest wide-open. Howeve...
by Doppelgänger
Thu Feb 15, 2018 7:26 am
Forum: Equipment Discussions
Topic: 4X LENS TEST PART 3 - ENLARGING LENSES
Replies: 26
Views: 5225

Let me know if you know of a repeatable consistent way to test Bokeh. All the best, Robert I wish I knew :) Here is an example that might point you in the right direction, from LensTip, on the Sigma 135 Apo . Evaluation of the OOF circles in shape, and in smooth transition between center and edges,...
by Doppelgänger
Mon Feb 12, 2018 10:24 pm
Forum: Equipment Discussions
Topic: Laowa 25mm F/2.8 2.5x-5x ultra macro lens
Replies: 78
Views: 30640

I have to emphasise here again that my setup is far from perfect, and normal people don't take photos of charts. Exactly. Nobody cares about photos of letters in bad Jansjö lighting :P The key elements of this lens are 1) it is brand agnostic ; 2) it is much more compact than the MP-E 65; and 3) it...
by Doppelgänger
Mon Feb 12, 2018 10:01 pm
Forum: Equipment Discussions
Topic: Longitudinal Chromatic Aberration 1X Macro Lens Test
Replies: 42
Views: 7716

Re: Longitudinal Chromatic Aberration 1X Macro Lens Test

LoCA 1X Test With a big pile of macro lenses at my disposal this weekend was my last chance to run a LoCA test before the 105 and 200 have to go back to Nikon. To keep things simple I did not include any Canon or Sony lenses this time but I plan on adding the Sony 90mm and a few Canon macro lenses ...
by Doppelgänger
Mon Feb 12, 2018 9:05 pm
Forum: Equipment Discussions
Topic: 4X LENS TEST PART 3 - ENLARGING LENSES
Replies: 26
Views: 5225

Much respect for the work you put into this.

Not sure if you've seen Coinimaging.com, but they have some interesting tests as well.

Still, tests on coins and inanimate objects, without backgrounds and bokeh/rendering considerations, are quite limited.

Best,
by Doppelgänger
Mon Feb 12, 2018 8:59 pm
Forum: Equipment Discussions
Topic: Canon MP-E 65mm f/2.8 vs Oshiro 60mm f/2.8 2x Lens Test
Replies: 17
Views: 3848

Interesting test. Would like to see your analysis on the new Laowa 25mm F/2.8 2.5x-5x.

Rather than static shots, how about comparisons on live subjects (or fungi/flowers) where bokeh and rendering considerations can be viewed?
by Doppelgänger
Mon Feb 12, 2018 7:51 pm
Forum: Equipment Discussions
Topic: Patent on Stack Focus Rail System
Replies: 66
Views: 12095

Perhaps it is time to organize a Cognysis boycott. I find those kind of business practices repellant. Yes, and back to the topic. Unless Cognysis has acquired patents in other countries (which I highly doubt), they have no claim against any non-American producer of macro rails. Even within America,...