Search found 479 matches

by Wes
Sat Aug 03, 2019 12:29 pm
Forum: Microscopes and optics
Topic: Wavelength and resolution (image embedding fixed)
Replies: 43
Views: 5994

Re: Wavelength and resolution (image embedding fixed)

For diatoms I have done this occasionally and the resulting image of one colour channel changed to b/w was somewhat better than all colour channels together. The method makes an apochromat from a simple achromat in a way. I tried this and I concur, there is a visible improvement of the green and bl...
by Wes
Sat Aug 03, 2019 10:43 am
Forum: Pictures and Videos
Topic: Prorocentrum lima (Dinoflagellata)
Replies: 6
Views: 2141

Re: Prorocentrum lima (Dinoflagellata)

I checked the organism in google images and yours is miles ahead in terms of detail that I can see. I find the thing on the right somewhat more interesting though. Do you know what is the brown pigment inside Prorocentrum lima?
by Wes
Sat Aug 03, 2019 10:39 am
Forum: Microscopes and optics
Topic: Wavelength and resolution (image embedding fixed)
Replies: 43
Views: 5994

Re: Wavelength and resolution (image embedding fixed)

Hi Wes, very impressive comparison, obviously you picked just the right diatom for this demonstration! How did you apply the filters and what type were they? Bob Thanks Bob, I chose the diatom that I could barely resolve by eye so I figured it must be on the limit of what this particular objective ...
by Wes
Sat Aug 03, 2019 10:23 am
Forum: Pictures and Videos
Topic: Fruit fly chromosomes
Replies: 16
Views: 3016

Re: Fruit fly chromosomes

Can you provide an idea of scale - width of the imaged field or something similar? I measured the pixel distance corresponding to 10 µm on a stage micrometer photographed under the same conditions and then set this as a global scale in imageJ which I used to generate the image below. The nucleus is...
by Wes
Sat Aug 03, 2019 9:47 am
Forum: Microscopes and optics
Topic: Wavelength and resolution (image embedding fixed)
Replies: 43
Views: 5994

Re: Wavelength and resolution (image embedding fixed)

The first comparison I posted wasn't not very well controlled. To improve the demonstration of the relationship between wavelength and resolution I isolated 3 relatively equidistant wavelengths. I made a mistake in the original post as the blue filter is 445 not 447 nm. I think now its much clearer ...
by Wes
Thu Aug 01, 2019 2:58 pm
Forum: Pictures and Videos
Topic: Fruit fly chromosomes
Replies: 16
Views: 3016

Re: Fruit fly chromosomes

Thanks Bob. I place the larva in a drop of saline and then grab it on both ends with two fine tweezers. I then pull it apart so the digestive tract comes out completely or partially. Using the tweezers I then tear the remaining tissue into smaller pieces and once there are no large chunks I squish i...
by Wes
Thu Aug 01, 2019 2:53 pm
Forum: Microscopes and optics
Topic: Wavelength and resolution (image embedding fixed)
Replies: 43
Views: 5994

Re: Wavelength and resolution (image embedding fixed)

Thanks everyone for the lively discussion, I'm certainly getting new ideas from reading your posts! 1. The image taken with the blue light has much more grain. Is this because the filter reduced the light level so the camera used a higher ISO setting? Whey you apply unsharp masking until the white l...
by Wes
Wed Jul 31, 2019 11:22 pm
Forum: Microscopes and optics
Topic: Wavelength and resolution (image embedding fixed)
Replies: 43
Views: 5994

Re: Wavelength and resolution

Yes I just realized. Give me a second to fix the permissions.
by Wes
Wed Jul 31, 2019 11:17 pm
Forum: Microscopes and optics
Topic: Wavelength and resolution (image embedding fixed)
Replies: 43
Views: 5994

Wavelength and resolution (image embedding fixed)

I am sure most if not everyone here is aware of the relationship between wavelength and resolution in a microscope. In essence the shorter the wavelength the better the resolution you get. I decided to test the relation using Frustulia rhomboides, that I got from Klaus Kemp, as a critical test objec...
by Wes
Wed Jul 31, 2019 11:02 pm
Forum: Pictures and Videos
Topic: Fruit fly chromosomes
Replies: 16
Views: 3016

Re: Fruit fly chromosomes

Thanks tgss, I will get a measurement. I keep forgetting to take an image of my stage micrometer but I will do it first thing in the morning.
by Wes
Wed Jul 31, 2019 10:52 pm
Forum: Pictures and Videos
Topic: Licmophora sp.
Replies: 4
Views: 1523

Re: Licmophora sp.

The amount of detail is amazing. I absolutely enjoy your diatom survey of the Alboran Sea. You are really good at stacking and stitching! How do you ensure the object stays static while you collect the multiple sets of images? Do you seal the edges of the coverslip? Out of curiosity how do you colle...
by Wes
Wed Jul 31, 2019 10:46 pm
Forum: Pictures and Videos
Topic: Fruit fly chromosomes
Replies: 16
Views: 3016

Re: Fruit fly chromosomes

Many thanks MichaelG., 75RR and mrsonchus for the positive feedback. I find an amazing array of cells and tissues in both the larvae and adult flies along with all sorts of internal intricacies from doughnut-shaped nucleoli to sausage-like chromosome.
by Wes
Wed Jul 31, 2019 8:24 pm
Forum: Pictures and Videos
Topic: Daffodil root tip mitosis
Replies: 12
Views: 3208

Re: Daffodil root tip mitosis

Very nice! Did you prepare the sections yourself? I really like how you can see the mitotic spindle fibers and fragmoplast in the last couple of images. If you can it might be worth checking the spindle under polarization. It has anisotropic properties and interacts with polarized in an interesting ...
by Wes
Wed Jul 31, 2019 8:19 pm
Forum: Pictures and Videos
Topic: Fruit fly chromosomes
Replies: 16
Views: 3016

Fruit fly chromosomes

Drosophila larvae grow to a large extent due to a process called endoreduplication, where the genome will double a few times but the cell would not divide. One consequence of this process is that cells become rather large. Another, more interesting effect of endoreduplication is the formation of gi...
by Wes
Tue Jul 30, 2019 4:15 pm
Forum: Beginner's corner
Topic: minimizing harm
Replies: 61
Views: 27390

Re: minimizing harm

IR light is not harmless too: It is transmitted by glass lenses and the eye doesn't detect too much of IR light to protect itself. As far as I know this is one of the reasons for the blue filter in the light path of many microscopes. I always thought the blue filter is to correct the color temperat...
by Wes
Tue Jul 30, 2019 1:49 pm
Forum: Beginner's corner
Topic: Correct application of oil for oil immersion?
Replies: 12
Views: 3340

Re: Correct application of oil for oil immersion?

For maximum resolution you want to apply oil on both the condenser and objective. The resolution is R=1.22λ/(N.A.objective+N.A.condenser). Without oil the N.A. of the condenser would be limited to ~0.9 Some people can't see a difference, others do. Say you use 0.55 um light and 1.4 objective and con...
by Wes
Tue Jul 30, 2019 6:10 am
Forum: Pictures and Videos
Topic: Pleurosigma sp
Replies: 4
Views: 1615

Re: Pleurosigma sp

Beautiful diatom 75'. The photo quality is amazing!
by Wes
Fri Jul 26, 2019 6:51 pm
Forum: Pictures and Videos
Topic: Alga reproduction
Replies: 7
Views: 1633

Re: Alga reproduction

I really like these images although I'm not quite sure what I'm looking at exactly. The thin elongated structures, are those individual cells?
by Wes
Wed Jul 24, 2019 5:58 am
Forum: Pictures and Videos
Topic: Sodium ascorbate
Replies: 6
Views: 2057

Re: Sodium ascorbate

Another crystal of sodium ascorbate, the 1st, 2nd and 3rd order interference bands are visible.
by Wes
Fri Jul 19, 2019 7:16 pm
Forum: Microscopes and optics
Topic: How to make a lambda wave plate?
Replies: 16
Views: 2402

Re: How to make a lambda wave plate?

Check out this post. http://www.microbehunter.com/forum/photographs-and-videos/pediastrum/ Look at the 50mm x x50mm. Full, 1/2 and 1/4 wave. $18 each for the full wave, $12 each for the 1/2 and 1/4. Click on "Specifications and Documents" below each description to get the full data, including thick...
by Wes
Fri Jul 19, 2019 7:13 pm
Forum: Pictures and Videos
Topic: Marine Foram
Replies: 7
Views: 1249

Re: Marine Foram

I use the rotary condenser to achieve Oblique. I offset the Brightfield port and vary the condenser diaphragm size. This creates effects similar to some dedicated Oblique stops. Cool, thats how I get oblique out of my condenser too (never tried with the 63/1.4 planapo though). Interesting I thought...
by Wes
Tue Jul 16, 2019 11:28 am
Forum: Microscopes and optics
Topic: How to make a lambda wave plate?
Replies: 16
Views: 2402

Re: How to make a lambda wave plate?

If its really clear the flower shop cellophane might be just what I need. Neat suggestion!
by Wes
Tue Jul 16, 2019 11:25 am
Forum: Pictures and Videos
Topic: Marine Foram
Replies: 7
Views: 1249

Re: Marine Foram

Wow, at first I thought what a great DIC shot but then I read the description. Tell us more about your oblique setup. To get this high quality detail out of oblique illumination at such an extreme NA is impressive to say the least. Excellent work! The organism is also beautiful. Overall very, very n...
by Wes
Mon Jul 15, 2019 6:59 am
Forum: Microscopes and optics
Topic: How to make a lambda wave plate?
Replies: 16
Views: 2402

Re: How to make a lambda wave plate?

abednego1995 wrote:Try mica. It used to be the material of choice :-)

Cheers,
John
Microworldofgems wrote:Edmund optical has lambda plate plastic sheet available for about 15 bucks for a 2 inch square.
Thank you John and Microworldofgems. These are great ideas!
by Wes
Sun Jul 14, 2019 3:13 pm
Forum: Microscopes and optics
Topic: How to make a lambda wave plate?
Replies: 16
Views: 2402

Re: How to make a lambda wave plate?

Yes I missed a new full lambda plate from Zeiss for $85.00, it was mislabeled in terms of its manufacturer (probably explaining the nice price) but I forgot the bidding deadline and I really regret it.
by Wes
Sun Jul 14, 2019 11:42 am
Forum: Microscopes and optics
Topic: How to make a lambda wave plate?
Replies: 16
Views: 2402

How to make a lambda wave plate?

Hello everyone Does anyone have experience with making DIY wave retarder plates for polarized light studies? I tried making one out of cellophane but it was not optically clear and deteriorates the image quality when placed between the specimen and analyzer; when placed between the polarizer and spe...
by Wes
Thu Jul 11, 2019 4:56 pm
Forum: Pictures and Videos
Topic: Salty landscape
Replies: 6
Views: 1596

Re: Salty landscape

Great shot, POL and oblique is such a nice combo! What kind of salts exactly are these?
by Wes
Thu Jul 11, 2019 4:43 pm
Forum: Identification help
Topic: Diatom and Amoebidae?
Replies: 7
Views: 1279

Re: Diatom and Amoebidae?

This is amazing! To see directional movement of particles inside the cell like you show is incredible. Also the stack is beautiful. Thanks for sharing 75RR.
by Wes
Tue Jul 09, 2019 7:59 pm
Forum: Introduce yourself
Topic: New to this forum, from Naperville IL
Replies: 9
Views: 2469

Re: New to this forum, from Naperville IL

Welcome Saul! The Alum shot in Rheinberg/Oblique/Cross polarisation is absolutely awesome.
by Wes
Mon Jul 08, 2019 6:47 am
Forum: My microscope
Topic: my Leitz SM lux
Replies: 4
Views: 2815

Re: my Leitz SM lux

Very nice scope Peter! Apparently a number of people can't deal with binocular heads but I never really understood what the problem was.