Urania ripheus, 60X

[Guppy]

Hi
Some color in the dull everyday life.



Kamera: Nikon D810
Objektiv: NIKON M Plan, 60/0.7 ELWD, 210/0
Belichtungszeit: Kamera 1 Sek. / Blitz ca. 1/40000 Sek.
ISO: 200
Beleuchtung: 4 Blitzgeräte bei 1/128 Leistung
Aufnahmedateiformat (RAW/JPG): RAW, 14Bit
Beschnittsbetrag in % (Breite u. Höhe): 35, 5
Stativ: Reprostand
Aufnahmedatum: 16.11.2019
Artenname: Urania ripheus
Stacking Software / - Methode: Zerene Stacker / PMax
Abbildungsmassstab: 60:1
Objektseitige Bildbreite / Höhe (mm): 0.39 / 0.39
Stacktiefe (mm): 0.11
Anzahl Stackschritte: 220, bei jedem Schritt 2 Bilder angefertigt, also 440 Bilder
Stackschrittgrösse (mm): 0.000496 (StackShot ein Schritt)
Diffusor: Eine Lage Kalkpapier

Kurt

[Chris S.]

Kurt,

Perfect image of a favorite subject!

Nice demonstration of what that objective can do when well-handled. I don't use my specimen of the Nikon M Plan 60/0.7 ELWD, 210/0 nearly often enough.

I'm curious about this: "Anzahl Stackschritte: 220, bei jedem Schritt 2 Bilder angefertigt, also 440 Bilder"

Which Google translates to "Number of stack steps: 220, 2 pictures made at each step, ie 440 pictures"

Did you actually use 440 pictures in your stacking? If so, why? Or does this refer to the total number of images recorded, given your choice to record as RAW+JPEG--in which case you likely used just one of these for stacking.

--Chris S.

[Guppy]

Hi, Chris
At each step (Step Size (mm) = 0.000496) of the stackshot I take two pictures
Due to slight vibration, the two images are not identical

Zerene Stacker, Tools; StackShot, StackShot Controller; Configuration,
Number of shutter pulses per focus step = 2

The resulting stack is a little bit clearer

Kurt

[rjlittlefield]

A lovely image, as always!

At each step (Step Size (mm) = 0.000496) of the stackshot I take two pictures
Due to slight vibration, the two images are not identical

When you process, do you have computational alignment turned on? (checkmarks on Shift X, Shift Y, at Options > Preferences > Alignment)

--Rik

[Guppy]

Hi Rik

I use the alignment setting:
Shift X = 20%
Shift Y = 20%
Scale = 20%
Rotation 20 degrees

Kind regards

Kurt

[rjlittlefield]

OK, thanks. Those are the default limits. The actual changes that you're getting will be much smaller.

The main thing I was wondering was whether the options have checkmarks. I assume now that they do.

--Rik

[Guppy]

sorry
the answer is yes
why do you ask, what is in need of improvement?

Kurt

[rjlittlefield]

why do you ask, what is in need of improvement?

Nothing at all is in need of improvement. I just wanted to make sure that I understood how the image was made.

It would be interesting, from a technical standpoint, to see graphs of the XOffset, YOffset, Scale, Rotate values that result from the computational alignment. Those can be exported easily from Zerene Stacker using File > Save Other... > Save Registration Parameters, then load the result into Excel for graphing. If you're using the StackShot rail directly, then at this magnification I expect that you're getting some pretty large movements that definitely require correcting for X, Y, and maybe Rotate. At this magnification it would be safer to un-check Scale, but apparently it's not causing you any difficulties with this subject.

--Rik

[rjlittlefield]

Kurt, thank you for sending to me the registration data and sample images.

I have run your sample images through Zerene Stacker two times: one time processing all of the frames and a second time processing every 2nd frame.

I confirm that processing every frame produces a result that shows slightly more real detail.

Then I looked closely at the source images to understand where the extra detail was coming from.

What I discovered is that you're not actually getting two frames at each focus point.

Instead, because of vibration in the system, you're getting slightly different focus points. In the set of 19 frames that you sent to me, there were only 2 frames that had arguably the same focus. So, in processing all the frames in this set, there are 18 different focus points, where processing every other frame gives only 10 different focus points.

The slight increase in detail then results from the larger number of focus points.

It is very much like using a smaller focus step, but getting the extra focus points from random variation rather than more precise mechanics.

Thank you for helping us to understand the result!

--Rik

[Guppy]

Hi Rik

Thanks for the review.
The gain in clarity is low, but it does exist.
Thus, I do not need a stacking carriage with blue buttons, which is four times as expensive than StackShot..
My essence is:
1. The stack step size does not have to be absolutely equal.
2. Vibration caused by a not absolutely stable setup, must not be a disadvantage, when the exposure time is extremely short 1/30000 sek.
3. Six pictures within the depth of field are better than three.
4. The extra work for twice as many pictures is small.

I am happy.

Kurt

[mawyatt]

Kurt, Rik,

This begs the interesting question of using vibration as an asset rather than determent to enhance resolution, kind of a "poor mans" pixel shifting

A technique that's employed in complex systems like Ring Laser Gyros for example, is to purposely introduce a "noise like" waveform to "dither" the system response and allow operation over a dead zone where the counter rotating photons lock onto each other. In post processing with the output waveform this "noise like" "dither" is removed. This technique was also use in some special type Analog to Digital Converters to remove INL effects.

With a good stiff setup, take an image just after the mirror is flipped up, then another image after everything has settled down with mirror still up, maybe a second or two later (or when flash has recycled). Use flash with a very short burst to expose each image. The 1st image should be slightly different in position due to the ringing effect of the mirror flipping up than the 2nd image which is where everything has settled. So the effect is to have 2 images at the same rail stack location but slightly different is actual position like a pixel shift.

Anyway, interesting thought!!

Best,

[mawyatt]

Hi Rik


Thus, I do not need a stacking carriage with blue buttons, which is four times as expensive than StackShot..


Kurt

Kurt,

You don't need to spend too much at all. The popular industrial THK KR type focus rails are exceptionally precise. They also work very well with the Stackshot Controller, you just need the proper connector which Cognisys can provide. If you are using Zerene with the Stackshot controller, the specific rail parameters are easily entered & stored, once you've done this the Stackshot System behaves just like it did with the OEM rail, but more precise.

I did this long ago and was very happy with the results, same goes for using with the nice Wemacro system and even the MJKZZ. Later I needed to move beyond the Stackshot controller and eventually ended up developing the Trinamic based controllers for single and multi-axis use.

Here's an example of what these THK devices are capable of producing.

https://drive.google.com/file/d/19wE-B- ... sp=sharing

If you try this with the Stackshot rail, it likely will not return to the same spot, although I haven't done this comparison test.

BTW, beautiful and very colorful image!!

Best,