Tick stack with Nikon 10x - New picture added

[acerola]

I also ordered the Nikon microscope objective. It arrived today. I have to test it right away. I want to make a shot from the mouth part of the tick. I found unfortunately the less interesting type (Dermacentor marginatus) a few weeks ago and I put it in the freezer. Now all I have to do is fishing it out. The mouth part of this tick is strange. It is more hidden than the plain old Ixodes ricinus.
I have to show you the first result. It is not retouched yet. I made the stack with CombineZM.
I need more time to process all of the shots, but my first impression is good.
There is a little CA at the edges of highlight but its almost unnoticeable if you did not zoom in.

Canon 20D with Nikon 10x objective + extension tubes (EOS + M42) 26 picture



The second picture is a crop, it is not the original size, but is close to it maybe 120%. It shows only the mouth part.

[Ken Ramos]

Pretty good photos (stacks) here Péter. I have never seen the business end of a tick before. I can see how they go about attaching themselves and why they can be so hard to remove now. This little thing reminds me of that alien from the movie Predator.

[acerola]

This is another stack, with more diffuser. The maximum magnification I can do with extension right now. I can try teleconverters if I want more, but I think it is enough now. I hope the next tick will be more tidy.

[rjlittlefield]

Péter,

This is looking good. Generally the more diffuse lighting works better, as shown in these images. At high magnifications, most surfaces start to look shiny and have obvious specular reflections with harsh lighting.

About more magnification, take a close look at the actual pixels in your images. The second image of your first pair suggests that your sensor is already capturing most or all of the detail that the lens offers. If it is, then more extension will just get you "empty magnification". This spreads out the same detail across more pixels, limiting your field of view without letting you see closer.

Using Charlie Krebs' spreadsheet with Numerical Aperture 0.3, Objective Mag 10, Relay Magnification 1, indicates required pixel size of 5.6 microns. The Canon 20D is shown as 6.4 microns per pixel. This pair of numbers (5.6 versus 6.4) suggests that you won't get significant improvement beyond another 20% or so. However, the spreadsheet is based on 2 pixels per feature, which is absolute minimum based on sampling theory. It is better to have more pixels per feature, up to 3-4, after which there is no significant improvement (see this thread). Bottom line is that you'll have to experiment to be sure. If you do run the experiment, I'd be interested to see your results.

--Rik

[acerola]

Thanks Rik,
I went trough in Charlie's stuff. I don't say I understand everything. But I think I'm working about in the right scale. My test shots covered between about 1.3-2.5 mm field of the longest side. I'm more of a practical guy, so I did not make test unless it is absolute necessary. In fact I so eager to get a result, that I hack everything together as a trial or test, and if it is works than I use it for a long time. (I'm "mounting" my camera for example on rice bags for stacking because this was at hand at first time and it works)
I will definitely look out for the resolution of the pictures in 100% view. Thanks for pointing it out.