Macro-photography

[Sam StonesParticipant @samstones42903]

Re your latest flower shot Raphael, I find it intriguing that so many flower petals, marine creatures, and other natural phenomena, e.g. Michael's micro-fossil, display in groups/segments of five.

By the way, besides being an excellent photograph, your daughter's pet is eye-catching

Sam

[Nicholas FarrParticipant @nicholasfarr14254]

Hi, I had another go at producing a stereo pair today, this would be a not so close up view. I first attempted one indoors on the floor with a digital multi-meter being the main view point. My technique was slightly different and I had to use the camera in the upside down position. After viewing from a central point, the camera was moved about 30mm to the right and then turned about 3 degrees back towards the centre view point and the first picture was taken, using the same distance and degrees the camera was moved to the left from the central view point and the second picture was taken. These measurements seemed to be a little too broad of field view and although it produced the stereo effect, the effect was only about 80 to 90 percent as ghosting on the left and right fringes of the opposite sides takes place. The camera in the first two stereo pairs, of which one is parallel viewing and the other is cross viewing, is a Canon IXUS170. The cross viewing one to me, looks a bit strange and I don't think it works very well. Both free-viewing and stereoscopic viewing produced much the same effect.

I next tried a pair outdoors and the subject is a Primrose, I had to use my Casio EX-70 as the battery needed a recharge on the Canon one, this time I only moved the camera right and left about 12mm and turned it about the same 3 degrees back towards the centre point view and this produced a much better stereo view in both free-viewing and with a stereoscope, although I found free-viewing a little harder to achieve to start with.

The photo below shows my set-up for both of these stereo pairs.

Regards Nick.

Edited By Nicholas Farr on 18/04/2021 21:53:03

[Sam StonesParticipant @samstones42903]

Congratulations Nick!

I see what you mean about ‘ghosting’. I would guess as you suggest that the camera positions are a bit too wide apart.

However, with cross-eyed viewing, both sets of pairs worked instantly for me, and there’s a great sense of depth with your low level approach. A good DOF makes all the difference too.

As I see them, the primrose pairs (again easily viewed) appear with the ‘cross-eyed’ pair below the ‘straight’ (stereo?) pair.

Sam

[Raymond GriffinParticipant @raymondgriffin40985]

Great to see the advances in taking 3D photos with a camera. My first attempts were very primitive. A piece of wood with stops at each end to limit the travel of the camera. Take a photo in one position, slide across and take the second.

I wondered if photos of the projector kit that I used in the 1970’s/ 80’s would be of interest. The first is a book published in 1982, that I found very useful. May be available today? The others are the Hawk Mk V1 projector that I used for lectures to people working in the specialities of anatomy and pathology. The projector was marketed by a company called Polaron in the UK who supplied consumables and equipment to us in laboratories specializing in electron microscopy. The projector has the look and feel of a custom-made item. The kit included over 100 pairs of polaroid glasses and a screen with a silvered surface. I also have a little device for aligning the photos in cardboard mounts. Good to see that this fascinating form pf photography continues to progress.

Ray

Mod Edit: rotated photo.

Edited By SillyOldDuffer on 19/04/2021 13:28:07

[roy entwistleParticipant @royentwistle24699]

Stereo photographs are usually taken with the camera taking two photographs separated by about 2 3/4 inches and through crossed linear polarising filters . the results are usually viewed through crossed polarising filters. I can see problems with using linear filters on digital cameras

Roy

[Michael GilliganParticipant @michaelgilligan61133]

Usually is an interesting word

MichaelG.

[Peter GreeneParticipant @petergreene36336]

Posted by roy entwistle on 19/04/2021 13:15:36:

Stereo photographs are usually taken with the camera taking two photographs separated by about 2 3/4 inches and through crossed linear polarising filters .

Stereo photographs are "usually" taken as a pair by a stereo camera with two lenses and viewed in an appropriate viewer. If the subject is static enough, they may be taken as separate shots by a regular camera with lateral movement between shots.

I think the reference to polarising filters is confusing the taking of stereo pictures with projecting and viewing them on screen.

[JAParticipant @ja]

I tried stereo photography a few years ago taking two sets of pictures about 3" apart of an object (Stuart 7A model) about three feet away. I did not use polarising filters. It worked but was not impressive. It was a bit like those disc stereoscopic viewers of my childhood in the 1950s.

JA

[Peter GreeneParticipant @petergreene36336]

'Viewmaster' you mean? They were fun to make yourself with the Viewmaster camera and matching cutter. The cameras used to be in fair supply (used) but the cutters were as scarce as hens' teeth (and demanded a commensurate price). I had both at one time but (unfortunately) sold them years ago. You can still get the blank reels.

Much of the bottom has fallen out of the stereo camera hobby because they were film-based and film is no longer plentiful. OTOH if someone wants to do stereo in digital, some of the smaller digital cameras look ideal for two camera side-by-side mounting. That used to be done with film cameras but camera size was often an issue in getting proper separation.

[Michael GilliganParticipant @michaelgilligan61133]

On the subject of VIEW-MASTER :

**LINK**

https://www.viewmaster.co.uk/htm/quickref.asp

**LINK**

https://www.ebay.co.uk/itm/ONE-OF-THE-HOLY-GRAIL-VIEW-MASTER-STEREO-VIEWERS-THE-RED-MODEL-E-WITH-BOXED/393233180005

MichaelG.

[Nicholas FarrParticipant @nicholasfarr14254]

Hi MichaelG, from your top link in the above post, is this one Weetabix viewer which is the one I mentioned earlier in this thread. The one we had was red in colour and I'm sure it had Weetabix in the area where VISTASCREEN is, the only stereo pair that came free in the Weetabix box that I can really remember though, was of a Porcupine. This viewer probably ended up busted between my siblings and myself, but I have purchased this VR Owl Kit which is really good IMO.

Regards Nick.

[Ian ParkinParticipant @ianparkin39383]

This is my stereo set up

a Fuji w3 camera which takes 3D stills and video

a owl viewer

and 100’s of stereo pairs

i print out the pairs almost automatically and stick to 3mm card

people love them takes them back to days of view masters

though some ( my wife) cant see the stereo

 

 

Edited By Ian Parkin on 20/04/2021 10:37:19

[Ian ParkinParticipant @ianparkin39383]

I also have this viewer which has a lenticular screen and shows stills or video without glasses in 3d

 

You can of course watch on a 3D tv or projector but with glasses on

Edited By Ian Parkin on 20/04/2021 10:54:22

Edited By Ian Parkin on 20/04/2021 10:54:38

[Michael GilliganParticipant @michaelgilligan61133]

Posted by Nicholas Farr on 20/04/2021 09:15:41:

Hi MichaelG, from your top link in the above post, is this one Weetabix viewer which is the one I mentioned earlier in this thread. The one we had was red in colour and I'm sure it had Weetabix in the area where VISTASCREEN is, the only stereo pair that came free in the Weetabix box that I can really remember though, was of a Porcupine. […]

.

Ahh … fond memories of an early TV advert

Something along the lines of:

There’s a new set of Weetabix 3D cards,

hurrah, hurrah

[…]

You can get the viewer from Weetabix

It’ll only cost you one and six

< etc. >

MichaelG.

[Michael GilliganParticipant @michaelgilligan61133]

Haven’t found the TV advert yet … but Nick might like this: **LINK**

http://cerealoffers.com/Weetabix_Ltd/Weetabix/1960s/Our_Pets_3D_Cards/our_pets_3d_cards.html

MichaelG.

[Nicholas FarrParticipant @nicholasfarr14254]

Hi MichaelG, thanks for the link, and they are the cards that were in the cereal packets, but we never managed the get any complete sets of any of the categories and I can't remember how just many cards we managed to get. The red viewer is the one we had and looking at that search link in the top right, in your link, it looks as if they did have vistersceen and not Weetabix in the base frame, but hey, I was only about seven or eight at the time. I also bought some cards on a buy it now, one of which is the porcupine. I can't remember any TV adverts, but we didn't get our first TV until the start of Wimbledon 1963.

Regards Nick.

[Sam StonesParticipant @samstones42903]

Having drifted further from the essence of this ‘Macro-photography’ thread, the mention of (left/right) image polarising for gaining a 3D effect raised a very distant memory along with a more recent observation.

In the early 50’s I recall visiting a local (Bolton, UK) cinema with my maternal grandmother. Each person received a pair of metal-framed spectacles, with instructions to hand them back at the end of the show. It was already clear to me that the ‘lenses’ were alternately polarised, one vertically, the other horizontal. I’m not sure how I knew this but, borrowing her pair of spectacles, I recall attempting to show her how, when one ‘lens’ was placed at right angles over the other, light would be blocked. What isn’t clear is how effective my explanation was in conveying to my GM, the very purpose of such a spectacle, pun intended.

Almost seventy years later, I was unable to resist responding to the current thread’s 3D occasional digression. This group of images demonstrates an effect that puzzled me. [If you’re in a hurry, the answer is in the link below.]

For no particular reason, I chose to display on my (aging) AOC 2436 desktop monitor a photograph of Waterman’s Dock in Hobart, Tasmania, (top left).

In each of the three remaining images, I’m holding in front of the PC monitor screen, a pair of polarising filters crossed at 90°. Where they overlap (as I explained to my GM long ago), most of the light is blocked.

What I found strange was if I repeated the test but rotated the pair at 45° as in the lower left image.

There was still a similar blocking where they crossed, but one filter almost completely blocked the covered part of the image. This suggests that the monitor is displaying a polarised image at 45°.

Taking the same pair of crossed filters and rotating them at about 60°/30° produced a similar result, although now allowing more light through (see lower right).

Testing our TV screen (a Bravia Oled) using a single filter, reveals that the display is horizontally polarised.

As often happens, I decided it was time to stop guessing and check the Internet.

Here I found an answer …

http://www.nelson-miller.com/why-are-lcds-polarized/#:~:text=Aside%20from%20the%20use%20of,feature%20a%20polarized%20filter%20layer

[A novel use of a pair of crossed polarising filters is to sandwich between them, a transparent object such as a PMM (acrylic) or GPPS moulding. As here from a CD case lid moulded in acrylic, the stress levels appear in multiple bands of the colour spectrum. The position of the gate into the mould appears in the upper left corner halfway up the part.]

Sam

The LINK 'mechanism' proved smarter than I realised, and had already inserted the URL.

Editing was unnecessary.

Edited By Sam Stones on 25/04/2021 00:38:01

[Martin KyteParticipant @martinkyte99762]

On the theme of MacroPhotography here are the finalists from our Lab's Science imaging competition.

As part of the LMB’s Microscope for Schools outreach project, the Science Image Award is a competition aiming to stimulate scientific curiosity in primary school children by connecting the microscopic world to everyday life. Each compeating primary school is loaned a hand held microscope camera and they submit their best images.

Results can be seen here:-

**LINK**

Great to see children getting so enthused.

regards Martin

[Peter GreeneParticipant @petergreene36336]

This, on the theme of both macro and 3D, Macrophant3D may be of interest (and other stuff on the same site).

[Michael GilliganParticipant @michaelgilligan61133]

Maybe not to everyone’s taste, but this is quite astonishing:

Cat Flea … colourised SEM images:

**LINK**

https://www.c-cina.org/stahlberg/research/res-art/art/color/

… and here’s the video:

.

MichaelG.

[Nicholas FarrParticipant @nicholasfarr14254]

Hi MichaelG, not a pretty thing, but yes it is quite astonishing. If its image was blown-up and used in a Sci-Fi movie, I guess not many people would recognise what it is.

Regards Nick.

[Michael GilliganParticipant @michaelgilligan61133]

This is an unexceptional photo of some scales on a rather bedraggled specimen on an old slide … but I thought it might be of some interest:

.

.

The donor was a Cinnabar Moth: **LINK**

https://butterfly-conservation.org/moths/cinnabar

The scales are imaged at about 170x on the sensor

Sensor pitch is 4.33 microns, so each scale is about 30 microns wide

This is approaching the limits of what we can usefully image using visible light and a single frame … so it is rather humbling to see what can be achieved with the Scanning Electron Microscope : **LINK**

Butterfly and Moth Scales

MichaelG.

[Nicholas FarrParticipant @nicholasfarr14254]

Hi MichaelG, I have to admit that the Cinnabar Moth link you posted was more interesting than the photo. I get a lot of Cinnabar moths in my garden and in 2018, with one thing or another (I was still doing a day job at this time) I didn't manage to mow my rough terrain lawns before it was rather full of the same plants in the photo of the Cinnabar moth caterpillars are on in your link. By the time I was able to mow, all these plants had many of these caterpillars feeding on them and knowing they were an endangered species, I decided that I would wait until they had all gone, I guess there must have been close to a thousand or even more caterpillars in all, OK so the lawns looked somewhat untidy for a while, but I thought the wildlife was much more important, but I do now always keep a sizable patch unmown now.

Regards Nick.

[roy entwistleParticipant @royentwistle24699]

Hi Nick

The plant in question is Ragwort

Roy

[Michael GilliganParticipant @michaelgilligan61133]

Posted by Nicholas Farr on 23/05/2021 08:10:33:

Hi MichaelG, I have to admit that the Cinnabar Moth link you posted was more interesting than the photo.

[…]

.

Thanks, Nick … You may well be right

… but, in my defence, I did post it with a specific purpose in mind.

Thanks for the photos of the caterpillars in-situ and en masse !

MichaelG.

.

As a bonus … here’s a good page about Ragwort:

https://markavery.info/2019/07/09/guest-blog-ragwort-friend-or-foe-by-paul-sterry/

Edited By Michael Gilligan on 23/05/2021 09:36:25

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