Ha,
Finally my new old Olympus BH2 BHT is cleaned, fixed and lubricated (so now the BH2 family has extended with a new member)
Thanks to Olav, Mario and Peter for spare parts (racks).
Thanks to Carl Hunsinger for wonderful instruction video's on the cleaning and lubrication.
Thanks to Bastian for the wrench.
Thanks to Gerhard for the Phase objectives.
Thanks to Anne for wonderful diatom slides.
My first stacked picture (Olympus PL5 M4/3, NFK 2.5, 9 pictures, Picolay wit default parameters): Feed Back appreciated.
Best, Maarten
Hi Marten,
very nice image. Congratulation.
What is missig on your BH-2 is this part:
(https://www.mikroskopie-forum.de/pictures010/286057_56680499.jpg)
Will come soon.
Regards
Stephan
Hallo Maarten,
Which objective did you use for the image, is this made with a phase objective? I see quite some chromatic aberration, I think something ist not yet optimal. How do the unstacked images look? When optimising, I would focus on single images and I wonder if this diatom needs stacking. Vriendelijke groeten,
Rolf
Ha Rolf,
Thanks for feedback, appreciated.
The objective used was a phase contrast one, this may be the reason of the color artefacts.
The depth of field of a single image is insufficient to cover the diatom.
Will continue experimenting and stack without phase next weekend and show the results.
Best, Maarten
Hallo Maarten,
ZitatThe depth of field of a single image is insufficient to cover the diatom.
Is this Arachnoidiscus? The picture below is a single image of Arachnoidiscus, also from a slide from Anne. Leitz Fluotar 25/0.55, normal brightfield. Best,
Rolf
Hmm thanks, work to do as I'm not able to get the same result ..... yet.
Is this a plan objective?
Maarten
Hallo Maarten,
It's a NPL Fluotar, so a plan objective, but that's not that important. A normal achromat also works well. Which objective exactly did you use? Best,
Rolf
Hallo zusammen,
ich freue mich über die schönen Bilder von Arachnoidiscus ornatus Ehrenberg aus einer Probe von Japan.
lg
anne
Hi, Your feed back is appreciated.
After seeing Rolf's picture I tried anew.
Data:
* Olympus BH2-BHT stand, NFK 2.5 projective, Adapter L, SPlan 20 na 0.46 and SPlan Apo na 0.7
* Olympus PL6 M4/3 camera, JPEG all auto settings, approx. 1/400 second
Observation 1: Still cannot get sufficient depth of field to capture the entire diatom (I tried 2 different slides)
Observation 2: Slightly better depth of field using the SPlan 20 with na 0.46 (as expected)
Observation 3: The setup is not stable enough: small shake visible in the eyepiece after each shot (not good)
Picture below is my 2nd try, Bright Field this time, 7 shots stacked with Picolay (standard settings, I'm new to P.)
Not at all satisfied: will try to eliminate the camera shake by separating the camera from the microscope stand (while maintaining proper length of the extension tube: 151.2 mm from base of adapter L to the sensor plane of the camera).
Hi Maarten,
it always is a question of image capture and editing too. Here I took your first image, used only the green channel and applied some unsharp masking. Since diatoms themselves have not much colour using just one colour channel makes the achromat the poor man's apo.
Cheers,
Bob
Ha Bob,
Thank you for the feed back.
Good thinking I will use a green filter with next phase experiment.
Best, Maarten
Hallo Maarten,
Your second image is already much better, there is way less chromatic aberration, this image is much cleaner. Is it made with the Splan or Splanapo? The only thing that needs to be solved are the vibrations that may be the reason that the image is not completely sharp. I see that you are using a mirrorless micro 4/3 camera. My image of Arachnoidiscus was made with a Olympus PEN EP1, so an older mirrorless micro 4/3 camera. When short exposure times are used with this camera, the images get blurry because of shutter vibrations, so I always use an exposure time of 2 seconds or longer. Regarding Bob's comments, it's fine to edit and process the image or use a green filter but it is much better to troubleshoot the chromatic aberrations and get rid of them. You want the unprocessed image to be as good as possible. Could you try a longer exposure time and take a single image? Best,
Rolf
Hi together,
shutter viration really is an important thing with diatom images. My wife had an Olympue E-Pl1 and it had quite some shutter shock, though a lot less than the SONY NEX 5. Some newer Olympus cameras have EFSC, electronic first shutter curtain, I think it is called silent mode.
It would be interesting to see the difference between an image taken with a green filter and one taken without filter where only the green channel is used.
Bob
Thank you Bob, my E-PL6 does not have this electronic shutter (you need an E-PL9 for this).
The previous picture was with the SPlan Apo 20.
Will try 2 polarisers to reduce the amount of light and/or use my CH2 trino with a separate stand to decouple the camera from the scope.
Best, Maarten
Hi Maarten,
the shutter runs back and forth when sitting on the microscope so a direct support towards the wall behind the microscope would help a lot to dampen the shock.
Bob
New (CH2-TR45 Trino plus a rigid stand: Camera no longer coupled to the microscope)
Old (BH2-TR30 Tino): with the Camera directly coupled to te microscope.
Hello, Thank you for the feed-back (keep them coming please) The next version: using a separate stand for the camera: aim is to reduce the un-sharpness caused by the camera shutter.
Data:
* Olympus BH2-BHT stand, NFK 2.5 projective, Adapter L, SPlan Apo 20* na 0.7
* Olympus PL6 M4/3 camera, JPEG all auto settings, approx. 1/400 second
* Bright field (no phase)
* Picolay stack (7 pictures) with standard settings (I'm new to P.)
* White balance correction in LR6 and output sharpening set to "Screen".
Best, Maarten
Zitat von: deBult in Oktober 31, 2020, 11:15:28 VORMITTAG
Hello, Thank you for the feed-back (keep them coming please) The next version: using a separate stand for the camera: aim is to reduce the un-sharpness caused by the camera shutter.
Data:
* Olympus BH2-BHT stand, NFK 2.5 projective, Adapter L, SPlan Apo 20* na 0.7
* Olympus PL6 M4/3 camera, JPEG all auto settings, approx. 1/400 second
* Bright field (no phase)
* Picolay stack (7 pictures) with standard settings (I'm new to P.)
* White balance correction in LR6 and output sharpening set to "Screen".
Observation: I think the sharpness improved, so step by step we are getting somewhere.
Please feed-back on improvement options !!
Best, Maarten
Hallo Maarten,
That's a big improvement and a world of difference from your first image. I am still curious how a single, unstacked image would look. You make one with the Splanapo and also the Splan? Best,
Rolf
ZitatI am still curious how a single, unstacked image would look. You make one with the Splanapo and also the Splan?
Best, Rolf
SPlan Apo 20* na 0.55
Splan 20* na 0.46
Splan 20* na 0.46 with IF550 green filter and converted to B&W (all channels)
Observation 1: Each change of objective required refocussing (they were on different exchangeable revolvers). So focus point is not identical. Depth of Filed is best at low na.
Plus each change of objective required tuning the condenser Köhler settings.
Observation 2: the one with the green filter looses sharpness: will need to check this as i only added the filter in the light path (and did not intentionally change focussing).
Feed Back appreciated,
Best Regards, Maarten
Hallo Maarten,
The image from the Splan really looks good. There are some parts of the diatom that are not completely in focus yet but with some oblique illumination you will be able to get everything sharp in a single image, without stacking. The residual blue color (because it's an achromat) I don't find disturbing at all, on the contrary, it brings some liveliness in the image. Best,
Rolf
Rolf: thanks for feedback
As I'm using an older model BH2 Phase Contrast condenser (the first photo in this thread you commented on was a phase contrast one) Oblique lightning is a bit complicated (I have a 3D printed insert I can try).
I'm working on a new batch of pictures: with NH and PLL phase contrast. Same diatom.
Best, Maarten
3D printed condenser oblique inserts used for the next experiment.
Olympus BH2-BHT, Phase Condenser, SPlan 20* objective, NFK 2.5 projective
Olympus E-PL6 m 4/3 camera on separate stand (to reduce shutter vibrations)
1) Left oblique insert used
2) Right oblique insert used
3) Wedge used
Observation 1: the "wedge" inserts gives the best overal sharpness impression (but the previous shown stacked images have better overall sharpness)
Observations 2: I still cannot match Rolf's technique or his Leitz optics ;)
Feed back appreciated,
Best Maarten
Hallo Maarten,
That second image is excellent. If you want more depht of field, you could try a more 'agressive' oblique illumination.
ZitatI still cannot match Rolf's technique or his Leitz optics
I don't agree, your second image is as good as mine. And remember that I used a better corrected objective.
I have a BH2 myself (that I funnily enough rarely use.....) that also has a plan 20 on it. I will do some tests with it next week so that we can compare our experiments in a better way. The reason I used the image of Arachnoidiscus taken with the Leitz objective was because I already had it. Best,
Rolf
Thanks Rolf,
Eagerly awaiting your results.
Best, Maarten
Hallo Maarten,
I did a few tests with my BH2 and a Splan20 objective. The projection eyepiece I have is unfortunately the NFK5xL, so with the OM photo adapter, the image gets too big. I improvised a bit to shorten the distance between the projective and the sensor of my Olympus PEN E-PL (first image). Only this way I could get a complete image of the Arachnoidiscus. I realise that this setup may not be optimal because the projective is calculated for a longer distance. The first image of Arachnoidiscus is taken this way. For the second image, I used a Sigma 30 mm lens as relais optics. With a projective, this is of course not needed but the image looks a bit sharper to me. Both images are single images taken in normal brightfield. I performed a whitebalance correction and a little contrast enhancement. Best,
Rolf
Thank you Rolf for doing this experiment
This sets a reference point: your entire diatom is sharp: so more depth of field (or a more flat specimen ?)
Do you have an idea why mine is not ? Tips to try out?
Our equipment is nearly identical?
Will give it another try this weekend using another scope, plus I'll use a test slide with defined flat surface (silver on a cover slide) kindly send to me by Wolfgang. The latter to validate I did not make an error when rebuilding this scope.
Best, Maarten
Dag Maarten,
Zitatyour entire diatom is sharp: so more depth of field (or a more flat specimen ?)
To really compare, we should have exactly the same specimen. I can sent you the slide, but don't break it ;) If you agree, sent me your adress via personal message.
ZitatDo you have an idea why mine is not ? Tips to try out?
See above.
ZitatOur equipment is nearly identical?
Not identical but at least highly comparable. Major differences are the projection eyepiece (NFK 5x versus NFK2.5x) and the camera.
Best,
Rolf
Hallo Maarten,
diese Species hat eine flache Seite und eine Seite die geformt ist wie eine flache Schale. Je nachdem welche Seite am Deckglas liegt musst Du mehr oder weniger "tief" vom Rand aus in die Mitte der Diatomee fokussieren. Auf Deinem Präparat könnte ich die Schalen mal von der einen und der anderen Seite gelegt haben. Vielleicht hilft das.
lg
Anne
Ha Anne,
This info helps: So I may have the flat side downwards ....
As I'm new to this Diatom world: I'm under the impression Rolf and myself are pucturng SIMILAR but not the same Diatom species?
My slide says the Origin is Russia (not Japan).
Maarten
Rolf,
ZitatTo really compare, we should have exactly the same specimen. I can sent you the slide, but don't break it ;) If you agree, sent me your adress via personal message.
I'll take you up on your offer: much obliged. You have PM.
Shall I send you my slide in return to picture on the Leitz?
I can reduce the differences in setup as I also have the Original Olympus e-pl camera and a NFK 5*
Best Maarten
Hallo Maarten,
ZitatI can reduce the differences in setup as I also have the Original Olympus e-pl camera and a NFK 5*
I don't think that's a good idea, as far as the projective is concerned. You have a better setup with the NFK2.5x and the OM photo-adapter and you want to have the best results from that. Mine was just a sub-optimal improvised and loose camera adaptation because of the too big enlargement of the NFK5x. Best,
Rolf
Ja Maarten,
Du hast recht, die Species von Rolf ist vermutlich A. ornatus aus Japan.
Deine Species könnte A. ehrenbergii sein.
Hier von Anatoly fotografiert:
https://www.mikroskopie-forum.de/index.php?topic=23160.0
lg
anne
A. ornatus (Rolf send me his slide)
* Olympus BH2-BHT stand, NFK 2.5 projective, Adapter L, Aplanatic condenser
* Olympus PL6 M4/3 camera, JPEG all auto settings, approx. 1/400 second
* White balance, Light sharpen & vibrance, exposure correction +1 stop, converted to BW (All in Adobe Lightroom 6)
* SPlan Apo 20* na 0.70
* Splan 20* na 0.46
A. ornatus again this time in phase contracts (Rolf send me his slide)
* Olympus BH2-BHT stand, NFK 2.5 projective, Adapter L, Abbe type phase condenser
* Olympus PL6 M4/3 camera, JPEG all auto settings, approx. 1/4 second
* White balance, Light sharpen & vibrance, exposure correction +1 stop, (All in Adobe Lightroom 6)
* Positive Low Low phase DAchromat PLL 20 na 0,40
* Negative High phase DAchromat NH 20 na 0,40
Hallo Maarten,
Thanks for the images. How do the brightfield images look before the black&white conversion? The depht of field looks OK, especially with the Splan20. Could you also try a long exposure time, like 2 seconds, to rule out any unsharpness due to vibrations? Best,
Rolf
Hallo Maarten,
die Hellfeldbilder sind super!
Freundliche Grüße
Peter
Thank you Peter R.
After I completed the refurbishment of the BH2_BTU scope I'm now testing it and work on improving my photo skills.
With the scope there came a series of objectives and not all of them are in 100 % good shape. In particular the SPlan Apo 20* shows a minor "chip" in the corner of the front lens impacting -amongst others - contrast,
The SPlan Apo 40 has a minor scratch (subject for next tests).
I'm currently working on 2 diatom slides mounted by Anne G. A. ornatus Ehrenberg from Japan and and A ehrenbergi from Russia
Rolf Hamvossen is guiding me on depth of field and sharpness. We both are exchanging the same slide via the postal service and comparing our results.
Next 2 pictures with The SPlan Apo 20* na 0.70: the first one is with a shutter speed of 1/60the of a second the second one 2 seconds: aim is to check the impact of vibration.
I'm using a CH2 trino: this allows me to disconnect the camera from the scope (My Olympus E-PL6 camera is known for shutter vibrations).
As I do not have a ND neutral density filter I used a POL filter plus set the voltage for the bulb to the lowest setting to achieve the 2 second exposure as recommended by Rolf.
Al post processing settings are identical except for the white balance this was set per picture as the 2 second versions were orange/yellow before WB correction.
No conversion to BW this time: so colour fringes caused by lens faults should be visible this time.
Observations:
* The Plan Apo has slightly reduced contrast compared to the SPlan
* the 2 second shutter speed does not improve the sharpness impression much compared to 1/60 (or 1/400): so the mounting of the camera is OK now.
* parfocality between the viewing and photo eyepiece-projection on the sensor is an issue: I have to do minor corrections: the E-PL6 camera display is way to small to do this properly
* The A. ornatus diatom has less depth/height compared to the A ehrenbergi: so no stacking required. (Stacking may help an additional bit with the outer ring of the diatom: no stacking used this time)
The Normal SPlan 20* na 0.46
The DPlan 20* na 0.40
Hallo Maarten,
The first image with the Splan 20/0.46 is excellent, you are good to go :). Indeed, no stacking is needed with this diatom. The image has also minimal chromatic aberrations, so no need to convert to black&white, which in my opinion makes an image a little 'lifeless'. So, your setup is OK and the vibrations due to short exposure times are minimal. Next week I will try to make some pictures with your slide. Best,
Rolf
Hallo Maarten,
I took some pictures of the Arachnoidiscus ehrenbergi from your slide. I used the Splan20 in normal brightfield and I focused more towards the edge in stead of the center, which you can clearly see, the center is a bit blurry. Results are comparable to your images. Only white balance correction and some contrast enhancement, no sharpening.
Left: NFK5x-L.
Right: a WHK10x eyepiece in the phototube and a Sigma 30 mm camera objective as relais optics.
I find the picture were I used the Sigma 30 mm objective a little bit better, like I have seen also in the previous test. Maybe it's because the projective is not at a optimal distance from the sensor.
Best,
Rolf
And 2 pictures with oblique illumination, single images.
Left: Splan20, oblique illumination by decentering brightfield position of phase contrast condenser on BH2
Right: Zeiss-Winkel 25/0.45, oblique illumination by decentering auxiliary lens on Zeiss-Winkel Standard GF
I have put the BH2 back in the closet, and my trusty Zeiss-Winkel GF took it's place again. I prefer the oblique illumination from the much older Zeiss-Winkel objective.
I will return the slide to you.
Hi Rolf,
I think you have decentered your illumination in different directions for these two images, giving a different relief impression. Here I turned your image 180° and to my eyes the relief effect is reversed. The Zeiss image is on the left now after turning it around. It shows a lot less chromatic error, clearly nicer than the Olympus image. Which eyepiece or projective did you use? AFAIK Zeiss and Olympus used different chromatic corrections, so this might explain the colour fringes in the Olaypus image it you had used a Zeiss eyepiece.
Bob
Hallo Bob,
Das Olympus Bild ist gemacht mit das Olympus projektiv NFK5x, also die Farmsäume habe nicht damit zu tun. Der Unterschied liegt dran das die schiefe Beleuchtung auf verschiedene Weisen zustande gekommen ist. Ich habe viel mit schiefe Beleuchtung experimentiert, und ich sehe immer das durch das dezentrieren einer Hilfslinse (was das BH2 nicht hat) einer der sauberste schiefe Beleuchtungen ensteht. Und die Zeiss-Winkel Achromaten geben sowieso weniger Farbsäume als viele andere Achromaten. Auf meiner Webseite kannst du das nachlesen ;). Beste Grüsse,
Rolf
Hallo Rolf,
Deine begründete Begeisterung für die Zeiss-Winkel-Optiken ist mir natürlich nicht entgangen! ;)
Deine letzten Olympus/Zeiss-Vergleichbilder hier eindrucksvoll, wie wichtig die Beleuchtung dafür ist, dass die Leistung der Objektive in der Praxis auch zustande kommt. Das mit dem Dezentrieren der Hilfslinse habe ich noch nie probiert, wird bei Gelegenheit unbedingt nachgeholt.
Viele Grüße,
Bob
Hallo,
Noch ein letztes Bild mit der Zeiss-Winkel 25/0.45 Achromat. Hellfeld und eine subtilere schiefe Beleuchtung womit die Auflösung eigentich besser ist als in die Vorherige Bilder mit dem hohe Relief. Weissabgleich und Kontraststeigerung, sonnst nichts. Beste Grüsse,
Rolf
A series of Oblique slides as per Rolf's example
A ornatus
Olympus BH2-BTU, SPlan 20 na 0.46
Olympus E-PL6 camera, NFK 2.5
Post processing: white balance adjust via the "white balance selector on the background", crop and mild sharpening. (Observation: need to improve on post processing: the white balance did not work out very well)
3 different 3D printed oblique inserts: placed inside the Achromatic 0.9 condenser (this is a flip condenser: I can put the inserts on top of the window a few mm above the condenser diaphragm)
* Slide 1: Normal Bright Field
* Slide 2: Using the decentred oblique insert
Slide 3: double circle oblique insert
Slide 4: wedge oblique insert
DarkField Condenser DCD 0.92-0.80
SPlan 20 na 0.46
Very nice darkfield image!
Simon
Thank you, this is my first DF using a dedicated DF condenser.