Search found 1488 matches
- Tue May 16, 2023 3:11 am
- Forum: Equipment Discussions
- Topic: New olympus 90mm 2x macro
- Replies: 114
- Views: 84444
Re: New olympus 90mm 2x macro
Doing a little thinking about the Olympus pixel shift and associated algorithm. Oly-pixel-shift.jpg The squares represent a typical Bayer layout. The circles represent the 8 successive positions of the blue sensel while shifting. Adjacent sensels of course shift in the same way. This means that each...
- Mon May 15, 2023 11:07 am
- Forum: Equipment Discussions
- Topic: New olympus 90mm 2x macro
- Replies: 114
- Views: 84444
Re: New olympus 90mm 2x macro
Yes. But each quarter pixel is shot eight times, at least twice with each Bayer filter (four times with green). Granted the values obtained in each single shot are not independent of the values of the neighboring shots, but with knowledge of the neighboring values, some of that dependence can be re...
- Mon May 15, 2023 10:31 am
- Forum: Equipment Discussions
- Topic: New olympus 90mm 2x macro
- Replies: 114
- Views: 84444
- Mon May 15, 2023 10:15 am
- Forum: Equipment Discussions
- Topic: New olympus 90mm 2x macro
- Replies: 114
- Views: 84444
Re: New olympus 90mm 2x macro
There are two Olympus pixel-shift modes, 80 Mpixel and 50 Mpixel. I mentioned them above; not really two different modes but two encodings of the same image, one with spatial redundancy reduced or removed. ...because a half-pixel shift, at best, can only overlap 50% of the neighboring Bayer filter ...
- Mon May 15, 2023 8:53 am
- Forum: Equipment Discussions
- Topic: New olympus 90mm 2x macro
- Replies: 114
- Views: 84444
Re: New olympus 90mm 2x macro
However, I do believe that a sensor-shifted 80 Mpixel image created by a 20 Mpixel sensor contains less information than an image recorded by a native 80 Mpixel sensor. Right, Olympus agrees also, downsizing their pixel-shifted jpgs to 50Mp if I recall correctly. But remember that the 80Mp sensor u...
- Mon May 15, 2023 8:13 am
- Forum: Equipment Discussions
- Topic: New olympus 90mm 2x macro
- Replies: 114
- Views: 84444
Re: New olympus 90mm 2x macro
[...]So I think it is not necessarily true that the Oly shifted image has a lower information density than the original unshifted image. You left out the added color information in the shifted image. We completely agree in this. I do believe that sensor-shift in the Olympus adds a considerable amou...
- Mon May 15, 2023 7:33 am
- Forum: Equipment Discussions
- Topic: New olympus 90mm 2x macro
- Replies: 114
- Views: 84444
Re: New olympus 90mm 2x macro
Pixel-shifted images are simply less information-dense than non-shifted images. One could perhaps try to verify this last statement by compressing pixel-shifted and non-shifted images with a lossless algorithm, and check whether pixel-shifted images compress to a higher extent than non-shifted imag...
- Mon May 15, 2023 6:11 am
- Forum: Equipment Discussions
- Topic: New olympus 90mm 2x macro
- Replies: 114
- Views: 84444
Re: New olympus 90mm 2x macro
[...] Just out of curiosity I re-sizes the 2x high-res image to 50% of its original size and then resized it to 200% and then applied a slight sharpening filter. And it looks exactly like it did before. It depends on the algorithms used for both operations of resizing. In addition, pixel shift quad...
- Mon May 15, 2023 12:56 am
- Forum: Equipment Discussions
- Topic: New olympus 90mm 2x macro
- Replies: 114
- Views: 84444
Re: New olympus 90mm 2x macro
Thanks for posting your comparison. I'm wondering why the target images are different sizes for each lens even though the pretense is that all are shot at 1:1. What am I missing? Added a new series shot with the 30 mm at 1x. I left in place the original series (shot at approx. 1.2x) because it show...
- Sun May 14, 2023 1:50 pm
- Forum: Equipment Discussions
- Topic: New olympus 90mm 2x macro
- Replies: 114
- Views: 84444
Re: New olympus 90mm 2x macro
Thanks for posting your comparison. I'm wondering why the target images are different sizes for each lens even though the pretense is that all are shot at 1:1. What am I missing? Good point, there are indeed differences. In the case of the 30 mm, it seems I made a mistake when setting the magnifica...
- Sun May 14, 2023 12:25 pm
- Forum: Equipment Discussions
- Topic: New olympus 90mm 2x macro
- Replies: 114
- Views: 84444
Re: New olympus 90mm 2x macro
Yes...the 60 is quite good at f/3.5 so it might have a resolution advantage. It took some time, but I got around to it: https://savazzi.net/photography/olympus-macro-lenses.html I included the Olympus 30 mm macro as a bonus. The page is not yet linked to the rest of the site, and the contents may s...
- Sun May 14, 2023 10:04 am
- Forum: Equipment Discussions
- Topic: New olympus 90mm 2x macro
- Replies: 114
- Views: 84444
Re: New olympus 90mm 2x macro
A small comparison with 60 mm macro Olympus would be very clarifying. Thanks Carlos Yes...the 60 is quite good at f/3.5 so it might have a resolution advantage. It took some time, but I got around to it: https://savazzi.net/photography/olympus-macro-lenses.html I included the Olympus 30 mm macro as...
- Tue May 09, 2023 1:13 pm
- Forum: Equipment Discussions
- Topic: Stackshot Vs. WeMacro Vs. QOOL
- Replies: 5
- Views: 1519
Re: Stackshot Vs. WeMacro Vs. QOOL
My current approach is somewhat different. I initially started with the MJKZZ system because their refurbished THK KR-20 rails (augmented with proprietary hardware to make them immediately usable "out of the box") seem more "serious" and reliable than the rails that come with WeMacro and Stackshot s...
- Sun May 07, 2023 12:29 pm
- Forum: Equipment Discussions
- Topic: Blackening edge lens elements and extension tubes
- Replies: 31
- Views: 2311
Re: Blackening edge lens elements
It depends on how black you want the girdle of optical elements to be, but a potential problem with paint is that the thickness of the dried paint can make it impossible to put the optical element back into a tight-fitting mount (and if you force the lens back into its mount, off comes the paint). A...
- Sat May 06, 2023 9:30 am
- Forum: Equipment Exchange
- Topic: fs:various microscope parts
- Replies: 4
- Views: 2074
Re: fs:various microscope parts
PM sent.Macro_Cosmos wrote: ↑Tue May 02, 2023 7:51 pmThe tilt stage is nice! I have seen them on stereomicroscopes, which allows for some interesting perspectives.
I would like to purchase the binoculars for AX, however, it is out of my price range and shipping would be very expensive.