1st ants, at 7x and 5x

Carmen · Post by **Carmen** » Sun May 03, 2015 2:24 pm

Below are my first humble photomicrographic attempts at ants.

First, an as yet unidentified ant, aprox 1cm size captured from the streets of Buenos Aires and frozen. Below at aprox 1,4x.

I ambitiously attempted to magnify the face to 7x. Below is the humble kitchen configuration used for this purpose.

The optical train:
Nikon CFi 10x Plan Achromat
RAF Camera M25x0.75 to M67x0.75 thread adapter
UV Slim filter (approx' 3.3mm)
Canon 100mm f/2.8L Macro IS
Canon 12mm ext. tube
Canon EF 1.4X III Telephoto Extender
finally imaging to a small ASP-C sensor set to 100 ISO

The result below:

151 focus slices were captured, at intervals of one mouse click on the >> button in the GUI of Canon's EOS utility software. Continuous incidental mixed kitchen light. 20 sec exp'. Focus stacking process P-max with zerene stacker program.

Sincerely, I was VERY disappointed with the result, but consider it a valuable learning experience.

NEXT, another as yet unidentified ant, perhaps 1mm size. This one from the floor of our laundry room, captured at end of (austral) summer and promptly frozen. I suspect it is a scout that entered through a minute crack in the wall. I imagine that the distances these tiny ants travel must be enormous, relative to their scale. Below at aprox 1x, just to show how small they are.

In this more modest attempt, I limited magnification to aprox 5x, due to increased awareness of the poor lighting and loss of light from the 1.4 teleconverter. Also attempted to arrange the specimen as flat as possible to facilitate stacking process.

146 focus slices were captured, at intervals of one mouse click on the >> button in the GUI of Canon's EOS utility software. Continuous incidental mixed kitchen light. 1.6 sec exp'. Focus stacking process P-max with zerene stacker program.

The result was more convincing to me. I concurr the 135 focal length is adequate for tube lens to Project to small APS-C sensor. But I am not so impressed with the combination of 100mm macro + 1.4 teleconverter as a tube lens.

I expect to have a flash unit soon, and hopefully a full frame camera at some future point.

Comments, questions, concerns, and considered opinions are greatly appreciated! Thank you!

Pau · Post by **Pau** » Sun May 03, 2015 2:47 pm

Hi Carmen,

Maybe you need the 12mm extension tube to mount the 100mm macro on the 1.4X tele extender but be aware that you are useing the lenses outside their specification. The tube lens usually works better if focused to infinite.

You can take a similar stack without the tube and extender and crop the image to get the same framing (i.e. magnification on computer screen) and compare the results.

(Another not related point: Because you don't use a whole microscope to take the images, according with the forum conventions they will be better placed at a "macro" forum)

Carmen · Post by **Carmen** » Sun May 03, 2015 3:07 pm

thank you Pau' for looking and for your help!

Pau wrote:Maybe you need the 12mm extension tube to mount the 100mm macro on the 1.4X tele extender but be aware that you are useing the lenses outside their specification. The tube lens usually works better if focused to infinite.

I was aware of that this combination excedes the manufacture's proposed range of use for the macro, but the combination is safe: no harm is done. I just wanted to try it! But so far, this combination really does not convince me -at least as a tube lens. (BTW, The ext' tube is necessary to connect to the teleconverter.)

Pau wrote:(Another not related point: Because you don't use a whole microscope to take the images, according with the forum conventions they will be better placed at a "macro" forum)

I apologize: I was not aware that the corresponding forum for this thread was begginner's macro. Sorry! If more appropiate to begginer's macro, ¿Can you do me the favor of passing it to that forum? Thank you!

Chris S. · Post by **Chris S.** » Sun May 03, 2015 10:16 pm

Duly moved.

--Chris

Carmen · Post by **Carmen** » Mon May 04, 2015 5:21 am

Chris S. wrote:Duly moved.
--Chris

Thank you Chris!

MaxRockbin · Post by **MaxRockbin** » Mon May 04, 2015 12:34 pm

I just tried a similar lens - the Canon 100mm 2.8 USM macro - as a tube lens for the first time - also using the Canon EOS utility to focus the tube lens for the first time and got a decent result.

The focus range was pretty broad- infinity to .5M and things were usably sharp even at .5M.

Still,I think I would go for focus rack focusing in the future with anything not pretty flat, just for the better sharpness at infinity.

I did find I get less vignetting with this tube lens on APS-C at infinity focus. That's another advantage of focus rack focusing, leaving the lens at infinity.

100mm Canon 2.8 USM w. Mitutoyo QV 2.5x APS-C sensor sample image:
https://www.flickr.com/photos/focusme/1 ... hotostream

The knee, about half way from center towards the lower right, is focused at .5M. The light hairs between the "chin" and body are closer to infinity.

The focus increment used was absurdly finer than needed for the stack, just because of my inexperience with the EOS utility (two single > per shot).

Carmen · Post by **Carmen** » Mon May 04, 2015 1:35 pm

thank you max for sharing and comments!

I see the artifacts you refer to in your foto of the bee, and concurr with your considered opinions. In my case, I have been using the above limited methods only provisionally. I expect to have a flash soon, and hope to have the basic stack shot kit later this year. Little by little...

In my opinion, the canon 100mm macro is a fine lens, I suspect you will really appreciate it as a general purpose macro lens. But I am inclined to agree with rik & chris, that as a tube lens to small APS-C format, a more optimal focal length would be a bit longer, like the 135mm. I wonder if anyone has tried to use an old 135mm enlarger lens for this purpose?

rjlittlefield · Post by **rjlittlefield** » Mon May 04, 2015 2:59 pm

Carmen, I think your big problem right now is blurring due to equipment vibration. You have something like 1000 mm of linkage from tabletop to the hinge of the tripod and then back down to the objective, at a magnification where 0.001 mm of lateral movement will smear subject features across 2 pixels. To hold even that still for a 20 second exposure would be something of a miracle.

I have just now shot a short test stack using a setup like yours except for using a Kenko teleconverter instead of Canon, and most importantly, using flash illumination at 1/8 power, about 1/5000 second exposure time. Even with the 100 mm focus ring set on "1 meter" (a sheer fantasy, given the 12 mm extension tube), the image looks OK at actual pixels. If you'd like to see, let me know and I can post here.

--Rik

ChrisR · Post by **ChrisR** » Mon May 04, 2015 3:35 pm

NB it's a Mitutoyo QV 2.5x. I have a dim recollection that the coverage was once or twice reported as not quite as good as the Mitutoyo 5x which I believe is the same FL.

NikonUser · Post by **NikonUser** » Mon May 04, 2015 3:48 pm

An ant expert may be able to offer an ID. For me, just getting "into" ants the 1st species looks like an Atta; spines on head and spines on thorax fits some species in this genus.
Looking forward to seeing more images as your technique improves (which it will do).

Carmen · Post by **Carmen** » Mon May 04, 2015 4:19 pm

Hello Rik!
Rik, the foto of the big ant at 7x is an embarrassment, but rather than hide the failure, I thought someone else might also benefit from the experience.

rjlittlefield wrote:Carmen, I think your big problem right now is blurring due to equipment vibration.
--Rik

I concurr with your considered vibration explanation. In fact this is my main motivation to arrange to purchase a flash. Also, the vibration explanation would seem to be coherent with the relatively better results acheived with the Nikon CFi 4x micro' objective, as opposed to the 10x (given my current provisional methods, tube lens, etc.).

rjlittlefield wrote: I have just now shot a short test stack ... If you'd like to see, let me know and I can post here.
--Rik

Yes please! I would love to see your tests!

rjlittlefield · Post by **rjlittlefield** » Mon May 04, 2015 7:59 pm

Here's the whole frame, reduced to 1024 pixels wide with Photoshop's Image > Image Size:

Here are center and lower right corners, as actual pixels, straight from Zerene Stacker PMax.

Center:

Lower right:

I've put the original image, saved straight from Zerene Stacker, here:
http://janrik.net/MiscSubj/2015/topic27 ... lution.jpg

Camera is a Canon T1i, 15.1 megapixels APS-C. Optical chain was a Kenko 1.5X teleconverter, 12 mm empty tube, Canon EF 200mm f/2.8 L IS USM macro lens set at 1m, Nikon CFI Plan Achromat 10X NA 0.25.

I hope this helps!

--Rik

Carmen · Post by **Carmen** » Tue May 05, 2015 10:38 am

rjlittlefield wrote:...Camera is a Canon T1i, 15.1 megapixels APS-C. Optical chain was a Kenko 1.5X teleconverter, 12 mm empty tube, Canon EF 200mm f/2.8 L IS USM macro lens set at 1m, Nikon CFI Plan Achromat 10X NA 0.25. --Rik

Thank you Rik! To summarize this test:

same Nikon CFI 10x micro' objective
tube lens 300mm (200mm + ext. tube + 1.5x teleconverter)
relevantly similar small APS-C sensor
relevantly similar mount, hanging perpendicularly from amateur tripod
electronic flash, with very brief pulse (perhap 1 milisecond resolution? does that sound correct?)

Correct me if I am in error: the magnification is about 15x? If so, then the clarity of the image would seem indicative of the resolving power of the micro' objective. Additionally, given 3x more enlargement than in my case, and mounted on a similarly trembly tripod, then this test is suggestive that the pulse of the electronic flash must be VERY brief -and an effective means of freezing a trembly image with super brief pulse of light, (given no other confounding factors) true?

If I understand and interpret this correctly, then I consider it in favor of my decision to purchase a respectable electronic flash. Again thank you!

Pau · Post by **Pau** » Tue May 05, 2015 10:57 am

electronic flash, with very brief pulse (perhap 1 milisecond resolution? does that sound correct?)

Usually it could be much shorter

Take a look: http://www.photomacrography.net/forum/v ... 563#161563 , just at the first links because you don't use a microscope

Carmen · Post by **Carmen** » Tue May 05, 2015 1:41 pm

Pau wrote: Take a look: http://www.photomacrography.net/forum/v ... 563#161563 ...

very interesting pau! The 2nd seems info-grafically correct.

Pau: we are arranging to purchase the Canon 600EX-RT flash. It is expensive, but has more power and generally reliable. The general idea is to set to much lower power, for more brief pulse. What do you think?