Comparison of 3 microscope objectives in super macro photography on a homemade macro bench

[fdupre]

Hello everyone,

I share with you the back of a processor (i3 8100) photographed in "super" macro mode with microscope objectives which are the Lomo 9x 0.20 objective, the Lomo 3.7x 0.11 objective and the Amscope 4x 0.10 planachromatic objective.
The 3 images were developed in Photoshop with the same corrections and under-sampled at 23.15% (in order to respect the size conditions of images shared on the MicroHunter forum)

Lomo 9x 0.20 lens without extension tube:
shooting :

pdv800px.jpg (144.24 KiB) Viewed 4812 times

Image stacked from 30 photos in Helicon focus with the C method

arriere_proc_lomo9x_sans_tubeMH.jpg (167.05 KiB) Viewed 4812 times

Lomo 3.7x 0.11 lens with 68 mm/2.68 in extension tube:
shooting :

pdv800px.jpg (139.47 KiB) Viewed 4812 times

Image stacked from 33 photos in Helicon focus with the C method

arriere_proc_lomo3.7x_avec_tubeMH.jpg (192.79 KiB) Viewed 4812 times

. . .

[fdupre]

. . .
Amscope 4x 0.10 planachromatic objective with 68 mm/2.68 in extension tube:
shooting :

pdv800px.jpg (157.17 KiB) Viewed 4810 times

Image stacked from 27 photos in Helicon focus with the C method

arriere_proc_amscope4x_avec_tubeMH.jpg (196.91 KiB) Viewed 4810 times

My opinion is that Lomo 3.7 and Amscope 4x lenses are very flat and sharp over the entire field, however the Lomo 9x is below the level of sharpness and is not flat.

Sincerely,
Frank

[MichaelG.]

Very interesting, Frank

It’s difficult to explain why [it’s really just a hunch] but could you please try the 9x with some extension ?

Obviously the magnification will change, but I suspect the field flatness will improve.

MichaelG.

[Scarodactyl]

This definitely tracks--the 9x is probaby just too far out of spec with such short extension. You look to have gotten one of the good amscope objectives--they don't all work so great but if you get a good one it's an amazing value.

[apochronaut]

This definitely tracks--the 9x is probaby just too far out of spec with such short extension. You look to have gotten one of the good amscope objectives--they don't all work so great but if you get a good one it's an amazing value.

The machining and optical manufacturing precision doesn't always give the optical design a chance and sometimes when it does, they point in the wrong direction.

[Scarodactyl]

Between that and some of them being a totally different design in the same shell it can get dicey.

[fdupre]

Hello everyone and thank you very much for your very interesting feedback,

Very interesting, Frank
It’s difficult to explain why [it’s really just a hunch] but could you please try the 9x with some extension ?
Obviously the magnification will change, but I suspect the field flatness will improve.
MichaelG.

Thanks MichaelG. Here is the image given by the Lomo 9x 0.20 lens with the 68 mm/2.68 in extension tube:
shooting :

pdv800px.jpg (130.16 KiB) Viewed 4707 times

Image stacked from 31 photos in Helicon focus with the C method

arriere_proc_lomo9x_avec_tubeMH.jpg (185.88 KiB) Viewed 4720 times

and so you were right. The field is clear everywhere

- Unfortunately, I have vibration problems at this high magnification: after adjusting the micrometric screw, I have to wait at least 5 seconds for the vibrations to calm down.
I think it's because of the flexible arm that holds the object :

new_banc800px_flex_arm.jpg (92.74 KiB) Viewed 4707 times

I am looking to replace it with a rigid but also adjustable system. For the moment I have only found systems low end like this :

bras_rigide.jpg (51.3 KiB) Viewed 4720 times

- In addition, I have a lot of trouble placing the subject and making the framing that I want at this magnification!

I would like your help please to find an adjustable rigid arm and a vertical and horizontal fine adjustment system to place the subject

Sincerely,
Frank

[fdupre]

while searching on the internet, I found the idea of using a camera lens to position the subject vertically very good :

very good idea.JPG (142.65 KiB) Viewed 4689 times

[Chas]

Frank, near the bottom of this photmacrography.net post there are a set of links to various people's macro setups ...some use the "low end" "helping hands" and I think in one of them these are attached to a Chinese x-y stage control for positioning:
https://www.photomacrography.net/forum/ ... php?t=7298

There are over 20 years worth of setups in there !

[MichaelG.]

Hello everyone and thank you very much for your very interesting feedback,
…
Thanks MichaelG. Here is the image given by the Lomo 9x 0.20 lens with the 68 mm/2.68 in extension tube:
shooting :

…
and so you were right. The field is clear everywhere

- Unfortunately, I have vibration problems at this high magnification:

Excellent result, Frank … thanks for trying that

I’m sure we will all be rushing to encourage you further by suggesting more solid support and positioning systems … but It’s nearly my bedtime, so any input from me must be delayed.

MichaelG.

[Sure Squintsalot]

I don't understand how you can infer flatness from 33 stacked images.

[Scarodactyl]

Not really flatness but the issue with the short extension is probably mostly spherical aberrations.

[MichaelG.]

I am looking to replace it with a rigid but also adjustable system. For the moment I have only found systems low end like this :
bras_rigide.jpg

Good concept, Frank … but, as you have noticed, not very well engineered.

I have not yet bought anything from them, but I rather like the look of SmallRig components:
.

https://www.smallrig.com/smallrig-unive ... -2157.html
.

https://www.smallrig.com/list/Magic-Arm.html
.

MichaelG.

[fdupre]

Hello everyone and thank you for your feedback,

Good concept, Frank … but, as you have noticed, not very well engineered.
I have not yet bought anything from them, but I rather like the look of SmallRig components:
https://www.smallrig.com/smallrig-unive ... -2157.html
https://www.smallrig.com/list/Magic-Arm.html
MichaelG.

Thanks for the links MichaelG ; Yes, indeed, I saw that the quality of the realization was not very good

Not really flatness but the issue with the short extension is probably mostly spherical aberrations.

Thank you for the info Scarodactyle. Do you think I should put in a longer extension ?

I don't understand how you can infer flatness from 33 stacked images.

Sorry for the confusion Sure Squintsalot, I must have misspoken in my previous post : I was just visually comparing the result of the sharpness in the corners of the image taken with the extension and compared to the other image taken without the extension (I was not talking about flatness of course ) :

without and with.jpg (102.64 KiB) Viewed 4600 times

Sincerely,
Frank

[fdupre]

Hello again,
For visual comparison, here is the back of the processor taken under the microscope with the 4x and 10x planachromatic objectives.
shooting :

pdv800px.jpg (136.63 KiB) Viewed 4573 times

4x - Image stacked from 34 photos in Helicon focus with the C method

arriere_proc_microscope4xMH.jpg (193.25 KiB) Viewed 4573 times

10x - Image stacked from 51 photos in Helicon focus with the C method

arriere_proc_microscope10xMH.jpg (184.99 KiB) Viewed 4573 times

Sincerely,
Frank

[apochronaut]

There is in fact no difference. The extension tube is just increasing the magnification and thus reducing the field. The same field in the short tube image is just as defined.

[Chas]

I have one of the 'low end' things and also the shorter smallrig 'Articulated arm'.
I think that you might be surprised by the 'low end' thing once you have tweaked it a little
The 'Articulated arm' * (on the smallrig webpage) is a bit problematical as the single tightening knob on the side locks both of the two ball ends and the main middle joint at the same time .. you might get it to work for specimen holding but I wouldnt say it is as easy to adjust as the 'low end' thing.
There seems to be at least two grades of the 'low end thing' ; a better looking soldering station one (with a locking screw for the crocodile clip rotation) I think the poorer looking one is the better of the two for positioning as the crocodile clips can be rotated gainst friction smoothly (they might need a squeeze with a pair of pliers) whereas with the better looking version you need to rotate and hold the specimen/crocodile clip whilst also trying to lock that rotation with the screw.
(I dont have any experience with the smallrig 'magic arm' joints).

* Once the 'Articulated arm' is locked it seems pretty rigid, but you would probably need to come up with something (to go on the end?) for the final positioning and rotation.

[Chas]

Oops: It seems that I misunderstood the design of the better-looking 'soldering helping hands' .... the crocodile clips on it are not designed to rotate in the collar... the collar and crocodile are meant to rotate around the collar's lower ball.
So it isnt a bad design after all
In fact if the locking screw that holds in the croscodile clip into the collar is undone the crocodile comes out and other things can be placed into the collar.

I have just hot-melted a ball bearing onto the end of the collar and put a platform on it ...very nice !
With the platform ~20cm up from the table surface I didnt see/detect any vibration with a 10x objective.

[fdupre]

Hello Chas,

I bought this rigid articulated arm. . .

bras-rigide_buy800px.jpg (113.69 KiB) Viewed 4438 times

. . . said entry-level "welding aid arm" (I paid 9 euros for it). This indeed seems to me a good way to replace my articulated arm which, I think, was a vibration generator.
I will test it too. . .
Sincerely,
Frank

[MichaelG.]

The heavy base and stiff rods should make a big improvement

The ball-joints can be improved [or replaced] later, if necessary.

MichaelG.

[fdupre]

Bonjour à tous,

I have one of the 'low end' things and also the shorter smallrig 'Articulated arm'.
I think that you might be surprised by the 'low end' thing once you have tweaked it a little
The 'Articulated arm' * (on the smallrig webpage) is a bit problematical as the single tightening knob on the side locks both of the two ball ends and the main middle joint at the same time .. you might get it to work for specimen holding but I wouldnt say it is as easy to adjust as the 'low end' thing.
There seems to be at least two grades of the 'low end thing' ; a better looking soldering station one (with a locking screw for the crocodile clip rotation) I think the poorer looking one is the better of the two for positioning as the crocodile clips can be rotated gainst friction smoothly (they might need a squeeze with a pair of pliers) whereas with the better looking version you need to rotate and hold the specimen/crocodile clip whilst also trying to lock that rotation with the screw.
(I dont have any experience with the smallrig 'magic arm' joints).

* Once the 'Articulated arm' is locked it seems pretty rigid, but you would probably need to come up with something (to go on the end?) for the final positioning and rotation.

You're right Chas, I'm quite pleasantly surprised

The heavy base and stiff rods should make a big improvement
The ball-joints can be improved [or replaced] later, if necessary.
MichaelG.

You are right MichaelG, with the rigid articulated arm, I no longer have any vibration
It was indeed the flexible arm which generated vibrations.
I also tinkered with a system to position the object horizontally and vertically more easily in the desired frame.

object_system_ang.jpg (161.26 KiB) Viewed 4402 times

For the vertical positioning system, it's an astronomy helical focuser that I already had and the zorizontal system is an entry-level macro rail.
I now have to find a more efficient light system and I believe it will not be too bad
Sincerely,
Frank

[Chas]

Ooo .. nice! That welding aid arm looks the same as mine ..it must be an International Design; ..'London-Paris-NewYork'
I wonder if the Lomo objective might have a small amount of fog on its lenses(?) ; If you put it over the light on the back of a mobile phone and look at the glass(s) obliquely (so the light out of it doesnt shine into your eyes) you might see a fog layer, if there is one.

[fdupre]

Hello everyone

Ooo .. nice! That welding aid arm looks the same as mine ..it must be an International Design; ..'London-Paris-NewYork'
I wonder if the Lomo objective might have a small amount of fog on its lenses(?) ; If you put it over the light on the back of a mobile phone and look at the glass(s) obliquely (so the light out of it doesnt shine into your eyes) you might see a fog layer, if there is one.

Hello chas, thanks for your return. I did as you advised me, and I did not notice any fog on my lenses.

FYI, I just bought a better "quality" articulated rigid arm, it seems to me:

gras_rigide_qualite.JPG (48.18 KiB) Viewed 4332 times

. . . and also this horizontal and vertical positioning table for really cheap (25 euros !):

table_positionnement_pas_cher.JPG (62.14 KiB) Viewed 4332 times

At this price,i have doubts about the product or I think it will never be delivered which is not serious because I ordered it on a site that always reimburses if we do not receive the package.

Friendly
Frank

[Chas]

I did not notice any fog on my lenses

That is good ..I have been caught out quite a bit when hurrying to try out 'new to me' older lenses
The micrometer block looks very sophisticated! I have an old measuring microscope with a micrometer x-y stage but I found the stage movements a bit too slow.

[fdupre]

The heavy base and stiff rods should make a big improvement
The ball-joints can be improved [or replaced] later, if necessary.
MichaelG.

Hello everyone,
I share with you a comparison of photos taken, one, with a flexible arm and the other with a rigid articulated arm:
flexible arm :

Photo taken with the flex arm - cropped image and 50% downsampled

arriere_proc_lomo9x_avec_tube_OLD_MH.jpg (182.37 KiB) Viewed 4217 times

rigid articulated arm :

Photo taken with the articulated rigid arm - cropped image and 50% downsampled

arriere_proc_lomo9x_avec_tube_NEW_MH.jpg (183.13 KiB) Viewed 4217 times

We can see that, as Michael G says, the articulated rigid arm notably improves sharpness by preventing vibrations that I could see while shooting with the flexible arm.
With the flexible arm, i had to wait at least 10 seconds between each shot otherwise the photo was really blurry and even after 10 seconds, there were still small vibrations (vibrations mainly due to me moving to turn the micrometer screw and clicking to take the photo via EOS Utility) whereas with the rigid articulated arm, no vibration.
(It should be noted that the light is not identical on the 2 photos but I think that this parameter does not influence the sharpness)

Sincerely,
Frank

[MichaelG.]

A very useful comparison there, Frank … thanks for sharing it.

It can be difficult to recognise the presence of blur caused by any form of small shake,

until you see what the image could look like without it !

MichaelG.

[fdupre]

A very useful comparison there, Frank … thanks for sharing it.

It can be difficult to recognise the presence of blur caused by any form of small shake,

until you see what the image could look like without it !

MichaelG.

Totally agree

[fdupre]

Hello everyone,

To visually confirm the blur caused by all forms of small shakes, here is a comparison of 2 images of the same subject (a hornet).
One with flash lighting and a flexible arm and the other with 2 LED bulb lighting and a rigid articulated arm.
The 2 photos are very close in terms of shooting parameters, the development in Photoshop and stacking parameters is same.
The major difference regarding the vibrations is the arm, one flexible with some vibrations and the other rigid with almost no vibrations.
With the flexible arm:

50% undersampled image

01-abeille_obj-amscope4x_flash_recadreMH.jpg (351.29 KiB) Viewed 4014 times

With the articulated rigid arm:

50% undersampled image

02-frelon_lomo3.7x_avec_objo70200_recadreMH.jpg (357.96 KiB) Viewed 4014 times

You can clearly see the difference in sharpness in the yellow hairs in the foreground. More blurred I find on the photo taken with the flexible arm.

Sincerely,
Frank

[fdupre]

Good morning,

I share 2 spider photo from the front.
The first shot with a Lomo 3.7 0.11 microscope objective and the second shot with a Lomo 9x 0.20 microscope objective.
Both were taken with the microscope lens screwed on a Canon 70-200 L f2.8 lens and a 5DmkII:

004-fourth_v_bench800px.jpg (111.31 KiB) Viewed 3948 times

Image stacked from 202 photos in Helicon focus with method C and smoothing at 1 - exposure time 1/60 of a second at 800 iso

araignee_lomo3.7x_objo70200_MH.jpg (137.07 KiB) Viewed 3948 times

Image stacked from 205 photos in Helicon focus with method C and smoothing at 1 - exposure time 1/45 of a second at 800 iso.

araignee_lomo9x_objo70200_MH.jpg (253.23 KiB) Viewed 3948 times

Best, Frank