Search found 422 matches

by Chas
Tue Mar 26, 2024 8:37 pm
Forum: Microscopes and optics
Topic: Substituting LED bulb for incandescent bulb
Replies: 7
Views: 336

Re: Substituting LED bulb for incandescent bulb

If you havent got any way of regulating the light (beyond an iris ) then it is quite easy to have too much light for your eye. I think that there is quite a mismatch between what is comfortable to look at with your eye and the sort of of light output you might want to take a video. It is evening whe...
by Chas
Mon Mar 18, 2024 9:41 pm
Forum: Microscopy accessories
Topic: Anti-Static for lenses.
Replies: 26
Views: 1381

Re: Anti-Static for lenses.

There are cheap (think school demo) electrostatic charge indicators, I dug one out and the charge on a record is very definitely negative, I tried it on some glass (eyepieces and a petri dish lid) I couldnt pick up anything. It might be the damp english climate and the adjacent metal parts thats cau...
by Chas
Mon Mar 18, 2024 8:50 pm
Forum: Microscopy accessories
Topic: Anti-Static for lenses.
Replies: 26
Views: 1381

Re: Anti-Static for lenses.

Maybe this is wrong; but I think that the antistatic guns for records try to neutralise the charge on the vinyl.
The charge on glass seems to be of the opposite polarity to PVC;
tribolectric series.jpg
tribolectric series.jpg (55.12 KiB) Viewed 1015 times
So it might have exactly the wrong effect.
by Chas
Sun Mar 10, 2024 7:58 pm
Forum: Identification help
Topic: Hmmm...what can this be?
Replies: 7
Views: 566

Re: Hmmm...what can this be?

jackieone, you might enjoy this book:
https://archive.org/details/micrographi ... 5/mode/2up
Of course you might not :oops:
by Chas
Wed Mar 06, 2024 8:36 pm
Forum: Digital processing
Topic: Chromatic aberrations filtering
Replies: 47
Views: 1761

Re: Chromatic aberrations filtering

bkt, out of curiosity is your microscope halogen or LED?
I noticed that in the (old?) specifications I came across it said it was a halogen system but it could take LED 'bulbs' too, if required.
by Chas
Mon Mar 04, 2024 12:03 pm
Forum: Pictures and Videos
Topic: Lurking in your waste water drain
Replies: 1
Views: 168

Re: Lurking in your waste water drain

Wow ! .. A new source for stuff.
(and maybe longer lasting than cheek cells too) .
:idea:
by Chas
Sun Mar 03, 2024 5:22 pm
Forum: Camera systems and imaging
Topic: OM1 Objective adapter
Replies: 21
Views: 6471

Re: OM1 Objective adapter

I have one of these already. I use it in the field with my Macro lens! You probably ought to have two, when you get going. As far as other kinds of lights go; if they are bright sources they might need another item to diffuse the light around the subject (much like flashguns do with macro) somethin...
by Chas
Sun Mar 03, 2024 4:55 pm
Forum: Pictures and Videos
Topic: High frame rate with a mobile phone : a Vorticella
Replies: 1
Views: 175

High frame rate with a mobile phone : a Vorticella

Prompted by topcode's ToupeTek high speed video footage. Here is a rough idea of what the 'slow motion' option of a mobile-phone camera over the eyepiece looks like (not as fast as the topecode's camera) Unfortunately this 3 year old phone has a scratched camera glass which is why there is flaring a...
by Chas
Sun Mar 03, 2024 9:44 am
Forum: Pictures and Videos
Topic: Various Spiral bacteria at high framerates(1400+)
Replies: 18
Views: 766

Re: Various Spiral bacteria at high framerates(1400+)

I did do rotifers a while back.

After you posted that, I had a quick go with a mobile phone (480 fps) hand held over the eyepiece and it slowed the wave down nicely.
I was using much less than 3W of light at the time and yet it still, sort of, worked :-)
So; thanks!
by Chas
Thu Feb 29, 2024 10:30 am
Forum: Camera systems and imaging
Topic: OM1 Objective adapter
Replies: 21
Views: 6471

Re: OM1 Objective adapter

A simple light that is good for the job:
Ulanzi VL49 feb2024.jpg
Ulanzi VL49 feb2024.jpg (49.9 KiB) Viewed 1457 times
Dont get the the VL49 version that has the letters 'RGB' in its name.

Just plonk it on table close to the subject, it lasts a good few evenings on a charge.

(It has a diffusing front surface)
by Chas
Wed Feb 28, 2024 8:40 pm
Forum: Camera systems and imaging
Topic: OM1 Objective adapter
Replies: 21
Views: 6471

Re: OM1 Objective adapter

In human terms the focus distance from the end of the objective will not be so different to the focus distance when is mounted onto your microscope. (~ 2 cm with a 4x and ~5mm with a 10x) I am not sure that the lens maths will help you to easily derive the distance difference but there are a nice se...
by Chas
Wed Feb 28, 2024 9:41 am
Forum: Camera systems and imaging
Topic: OM1 Objective adapter
Replies: 21
Views: 6471

Re: OM1 Objective adapter

Am I going to be in need of spacers to get the 10x objective to the correct distance to be in focus? Are you having trouble with the 10x objective, in particular ? i.e. Is the 4x objective working OK on the cone ? Using a microscope objective on a camera is a pretty 'freestyle' thing ...all sorts o...
by Chas
Sun Jan 21, 2024 8:41 pm
Forum: Microscopes and optics
Topic: NIKON PlanApo 100X/140 oil that is a PlanApo 60X/140 oil
Replies: 121
Views: 8326

Re: NIKON PlanApo 100X/140 oil that is a PlanApo 60X/140 oil

There are quite a few objectives taken apart on this site:
https://www.funsci.it/schede-tecniche.html

(It doesn't have your objective, but it might give some general idea about how it might be put together)
by Chas
Sun Jan 21, 2024 2:39 pm
Forum: Microscopes and optics
Topic: NIKON PlanApo 100X/140 oil that is a PlanApo 60X/140 oil
Replies: 121
Views: 8326

Re: NIKON PlanApo 100X/140 oil that is a PlanApo 60X/140 oil

Do just check (with a stereo or magnifier) that above or below the knurled ring there isn't another thread that splits the barrel. It is sometimes a bit of a guess whether an edge is just a machined ledge or the edge of a thread .. scraping into the edge with a needle can sometimes help to see what ...
by Chas
Tue Jan 16, 2024 10:17 am
Forum: Camera systems and imaging
Topic: How can i fix the checker pattern created from 3x binning?
Replies: 2
Views: 1133

Re: How can i fix the checker pattern created from 3x binning?

I can hardly see any checker pattern, just a bit of roughness to the background.
It is great to see the flagella in slow motion!! :-)
....Hypnotic.

I guess doing this requires quite a powerful illumination?
by Chas
Thu Jan 11, 2024 2:41 pm
Forum: Beginner's corner
Topic: Looking for camera for Swift SW380B
Replies: 28
Views: 8198

Re: Looking for camera for Swift SW380B

If you would like to explore using your mobile phone a bit further there are a couple of things to be aware of: A] Over time the eyepoint of eyepieces has got higher which can mean that the basic camera phone clamps can sit in the wrong place. B] Some mobile phones dont let the user manually set the...
by Chas
Sat Jan 06, 2024 9:34 pm
Forum: Pictures and Videos
Topic: Advices to improve my pictures
Replies: 11
Views: 7762

Re: Advices to improve my pictures

As for cleaning the lens you need a good amount of dirt to really notice the difference in contrast It might be the English weather or perhaps the English glass but just about every single eyepiece from the black era microscopes I have has needed a good clean. For some reason the few eyepieces that...
by Chas
Sat Jan 06, 2024 9:10 pm
Forum: Microscopes and optics
Topic: Diy phase contrast on BHS
Replies: 3
Views: 4833

Re: Diy phase contrast on BHS

I dont know if this would work for your particular microscope but see here: https://microscopyofnature.com/low-budget-condenser-darkfield-phase-contrast-and-circular-oblique-illumination Or perhaps this?: http://www.microscopy-uk.org.uk/mag/indexmag.html?http://www.microscopy-uk.org.uk/mag/artjan01/...
by Chas
Sat Jan 06, 2024 11:18 am
Forum: Pictures and Videos
Topic: Advices to improve my pictures
Replies: 11
Views: 7762

Re: Advices to improve my pictures

Actually, Sacrodactyl is correct :-)
by Chas
Fri Jan 05, 2024 10:00 pm
Forum: Specimens, samples and slides
Topic: How to best photograph parasitoid wasp collection for ID
Replies: 6
Views: 5947

Re: How to best photograph parasitoid wasp collection for ID

A deep cell sounds like a good idea, but if you are after more control in terms of rotation, you could try putting them in a thin walled glass tube and then rotate that . Things like this were made 100 years or so ago. The only example pic I can find at the moment is this one: https://www.flintsauct...
by Chas
Wed Jan 03, 2024 12:02 pm
Forum: Home-made microscope adaptations
Topic: Dichromatic Illumination?
Replies: 61
Views: 115430

Re: Dichromatic Illumination?

'Why the flare out' .. 'why the black ring' ? My guess; the light that is entering the cone and going less than the critical angle will exit the cone and other light (heading straighter) will bounce down the inside of the cone (?) I think that the cone ought to concentrate light. Conrad Beck in 'The...
by Chas
Wed Jan 03, 2024 10:15 am
Forum: Beginner's corner
Topic: Question Regarding Darkfield Condensers
Replies: 39
Views: 115045

Re: Question Regarding Darkfield Condensers

Just pop out the BF condenser and pop in the DF condenser. No It would be nice wouldn't it be? ......Tooo nice, the manufactures might say. (and if you really want the freedom to use a standardised condenser you are going to have to purchase a special mount ). Of course they each maintained other d...
by Chas
Tue Jan 02, 2024 6:57 pm
Forum: Beginner's corner
Topic: Question Regarding Darkfield Condensers
Replies: 39
Views: 115045

Re: Question Regarding Darkfield Condensers

The inability to get the correct height for the DF oil condenser is strange, especially given the fact that I have found no such difficulty. Would I be right in thinking that when you used the darkfield condenser on the No.5 that it came pre-mounted on a push-in disc similar to the disc with the RM...
by Chas
Sun Dec 31, 2023 1:02 pm
Forum: Beginner's corner
Topic: Question Regarding Darkfield Condensers
Replies: 39
Views: 115045

Re: Question Regarding Darkfield Condensers

Maybe the first thing to do is to try out the DF condenser head? ... You could attach the DF head directly to the RMS condenser mount disc with some hot melt glue if the RMS disc is flat enough in the right area and the threading on the head is long enough to raise the darkfield condenser head to to...
by Chas
Sat Dec 30, 2023 10:02 am
Forum: Beginner's corner
Topic: Question Regarding Darkfield Condensers
Replies: 39
Views: 115045

Re: Question Regarding Darkfield Condensers

It seems that Spencer had to put a darkfield condenser onto an extension tube at some point: Spencer darkfield long.jpg I have a Leitz ' helldunkenfield' (whose head has pretty much the same thread measurements as you measure on your condenser) and fitted that into a Watson centering mount with a pu...
by Chas
Fri Dec 29, 2023 12:49 pm
Forum: Illumination Techniques
Topic: Does phase contrast make sense for its price?
Replies: 49
Views: 32385

Re: Does phase contrast make sense for its price?

I think more likely, use a 70 to .75 objective. with your dry DF condenser. Maybe even less The dry darkfield condenser made a good annular illuminator for the 1.25 oil objective. The yeast cells dont seem to be the right target for darkfield. Quite a nice set of three photographs in the middle of ...
by Chas
Fri Dec 29, 2023 11:59 am
Forum: Beginner's corner
Topic: Question Regarding Darkfield Condensers
Replies: 39
Views: 115045

Re: Question Regarding Darkfield Condensers

There seems to be a general and ongoing problem uploading images :
viewtopic.php?f=8&t=19281
by Chas
Fri Dec 29, 2023 11:26 am
Forum: About the website, the magazine and this forum
Topic: New trouble uploading images...
Replies: 19
Views: 16165

Re: New trouble uploading images...

29 December;
'The image file you tried to attach is invalid'

:-(
by Chas
Thu Dec 28, 2023 9:22 am
Forum: Illumination Techniques
Topic: Does phase contrast make sense for its price?
Replies: 49
Views: 32385

Re: Does phase contrast make sense for its price?

What about the movement of the organelles inside the yeast cells? Is that brownian movement as well or rather a result of cellular function and metabolism? Or both? Here is a timelapse video, taken in light-grey darkfield; a dry darkfield condenser under a 1.25 oil Lomo objective (it covers about 1...
by Chas
Mon Dec 25, 2023 9:26 pm
Forum: Illumination Techniques
Topic: Does phase contrast make sense for its price?
Replies: 49
Views: 32385

Re: Does phase contrast make sense for its price?

My 40x images of yeast are not any better (slightly worse in fact ) however the Cooke Troughton & Simms phase kit I used is not new (cough). The 95x 1.3 does rather better at showing interior detail. If you look at DIC images of yeast they are maybe the best you could dream for: https://www.youtube....