1.67x Testing - Spitta Diatom Slide

[josmann]

So as I reported in another thread, I recently found out that I've had a pristine 1.67x Olympus photo eyepiece just sitting in a trash bag for months - maybe a year or more. I've always been a little unhappy with the amount of cropping that you get with a 2.5x eyepiece. At lower magnifications, it's okay, but things just don't look tremendously sharp when you go to 40x+ objectives. I've always wanted to try a 1.67x out, but didn't want to spend out the nose for one.

Here is some of my first work with the 1.67x. I'm using a DiatomLab arrangement and my 40x SplanApo. It's a composite image with the "best" single focus of each frustule. What's really awesome and fortunate is that I can be parfocal to the eyepieces and get the whole Synedra in view with the rest of the diatoms - not something that's possible with the 2.5x! In photo mode (4240x2832), the image circle peeks in at the corners, but, in video mode (3840x2160), this is basically not visible though there is likely a little bit of vignetting if you squint. Using the 1.67x for video has a couple benefits: 1. the denser detailing makes 4K video look sharper at higher mag, 2. the denser light means you can shoot at lower ISO. There may be some detail loss at 10x just due to sensor resolution limitations, but I think it will be minor overall. I'm definitely going to use this puppy for a while and see how I like it!

FULL RES

spitta_slide_blue_DIC_sq.jpg (66.68 KiB) Viewed 1588 times

spitta_slide_blue_DIC.jpg (60.19 KiB) Viewed 1588 times

[Phill Brown]

Is there any chance there is shutter shock or vibration?
Looks like some motion blur rather than resolution.

[MichaelG.]

Could you send me some of your old bubble-wrap please ?

MichaelG.

[josmann]

Is there any chance there is shutter shock or vibration?
Looks like some motion blur rather than resolution.

Hi Phill, these are heavily compressed due to the filesize limitations of the forum - please check out the full resolution image here for all your pixel-peeping needs: https://i.redd.it/0v21z2xijkbb1.png

It's a pretty hefty mirrorless camera on a BHS base so vibration should be minimal. Keep in mind that only one shot is used per frustule - no focus stacking so there will be blurred regions.

[josmann]

Could you send me some of your old bubble-wrap please ?

MichaelG.

Sure! $600 per fistfull, all sales are final, offered as-is, no refunds, no take-backsies

[josmann]

Just got done with my first 4K livestream using the 1.67x.

This is the correct lens for full frame videography. Hands-down. I've never gotten such detailed and punchy imagery with the 2.5x. I'm never going back!

[Phill Brown]

Is there any chance there is shutter shock or vibration?
Looks like some motion blur rather than resolution.

Hi Phill, these are heavily compressed due to the filesize limitations of the forum - please check out the full resolution image here for all your pixel-peeping needs: https://i.redd.it/0v21z2xijkbb1.png

It's a pretty hefty mirrorless camera on a BHS base so vibration should be minimal. Keep in mind that only one shot is used per frustule - no focus stacking so there will be blurred regions.

Thanks, still seeing something.
Could be light path alignment behind the subject, including an iris.
Could be something that goes clunk or how the shutter is released.
Could just be the way I'm looking at it with tired old eyes.
Good luck, don't see any dust which is always a good effort.

[ddy5]

Great find with the NFK 1.67 - not common, expensive, and, based on your successes, definitely valuable.

I'm with Phill, however: something doesn't look quite right with your diatom images. I also thought it was motion blur at first, but your HiRes images don't support that. Maybe something about the colors? an aberration of some sort? It's particularly odd, because your DIC images/videos are always so beautiful and free of artifact.

Or maybe I just share Phill's aging eye syndrome ... not unlikely ...

Cheers, David

[josmann]

Great find with the NFK 1.67 - not common, expensive, and, based on your successes, definitely valuable.

I'm with Phill, however: something doesn't look quite right with your diatom images. I also thought it was motion blur at first, but your HiRes images don't support that. Maybe something about the colors? an aberration of some sort? It's particularly odd, because your DIC images/videos are always so beautiful and free of artifact.

Or maybe I just share Phill's aging eye syndrome ... not unlikely ...

Cheers, David

Haha, well I’m going to need you to be more specific than “something doesn’t look quite right”! Can you point out a specific area with something that you’re seeing?

It may just be this position on the DIC slider? Usually I get softer imagery out here than at the “proper” gray setting just to the side of extinction.

If you skip to 4 minutes in and 12 minutes in on my latest livestream, you can see me using the same lens on the same scope, just at the more traditional setting (although not on diatoms). Do you see anything out of the ordinary there? Make sure you set the video to “4K” even if you’re not on a 4K display.

[ddy5]

The diatom second from the left shows the effect most. It might be some sort of psychophysical effect arising from the adjacent, saturated colors.

In any event, it's not a big deal. Clearly not a flaw in your overall system because your video imagery is great.

Cheers, David

[josmann]

The diatom second from the left shows the effect most. It might be some sort of psychophysical effect arising from the adjacent, saturated colors.

In any event, it's not a big deal. Clearly not a flaw in your overall system because your video imagery is great.

Cheers, David

It’s funny you mention that one - it’s the only diatom where I did a bit of “cleaning up” around the edges. It has a pretty extended blur coming off of it - Epithemia frustules are surprisingly tall!

I took some more images just now with my cell phone showing how the illumination on these changes depending on the DIC slider position. I did my best to approximate the original focus. One thing to note is that if I go farther out into a lighter blue, that red shading goes away on the Epithemia. https://drive.google.com/drive/folders/ ... gyC4GZHoWO

[ddy5]

Interesting ... looks like it probably is some sort of color effect that I'm picking up on. To my eye, the image emphasizing magenta is most affected and one emphasizing blue is least affected.

Cheers, David

[Lomonaut]

Fantastic and ultracrisp imagery! The smaller crop factor really helps - and so do the the planapos