Here is a list of all the postings Sam Stones has made in our forums. Click on a thread name to jump to the thread.
Thread: Macro-photography |
28/05/2020 23:43:33 |
Michael, I've just had another look at Saul's first pair of images and they (eventually) materialised. With egg on my face, I'm puzzled as to why they take longer than most other pairs I view. Any clues? Sam |
28/05/2020 23:30:31 |
As always Michael, another excellent contribution. In contrast, I can’t do parallel, but cross-eyed is instantaneous. It could also be how I view the world. SIRDS, (I had to look it up Bandersnatch) often took my eye/brain several seconds before the depth (3D) materialised. With so much cross-eyed practice of side-by-side pictures, I had, (for the kids and those not in the know) I had the irritating ability to ‘see’ all the differences in ‘Spot the difference’ pictures. When the two images are one above the other, it’s necessary to turn them around for side-by-side viewing. Sort of gives the game away a bit. The effect is curious in that the eye/brain (interplay?) cause the differences to twinkle - on and off. Sam PS – I’ve forgotten who ‘asked’, but it’s also possible I went for the circuit (PCB) layout because of its shallowness, needing little attention to DOF other than stopping down to f/16. The nylon screw and the capacitor next to it are blurring slightly. While f/32 was the smallest aperture certain voices in my head would be saying “Refraction!” Edited By Sam Stones on 28/05/2020 23:33:44 |
Thread: J.T.Slocombe micrometer very old |
28/05/2020 05:14:13 |
Yes Mike, 1/64"s on the back. If you wonder about my name, 'D' is my first initial. As I said earlier it was second hand. It had been engraved with someone else's name before I stuck it onto the engraver. I took the trouble to move in close and perhaps for the first time noticed it was a No.230. Now for a short story ... In the toolroom, we were discussing a very cheap brand of micrometer. They were die-cast in aluminium with a correspondingly low cost thread assembly. It may even feature here … [Search for die cast, there are two on Page 71] During the conversation, a story emerged about the ‘initiation ceremony’ of any freshly appointed toolmaker once they had settled in. For the initiation to work, it was also important that the new arrival was taking sufficient interest in their surroundings. The story continued, going something like this … Ensuring the new arrival could see him, Joe, one of the old timers shouts from far across the shop “Hey Fred, lend us thi nawt ta one!”. “Owd on a minit!” Fred would reply. He then proceeded to grab his extremely cheap micrometer from amongst his spanners, and pretend to measure something with a tight fist around the barrel. Then with a deft flick of his wrist, he would launch the mike along the concrete floor in Joe’s direction. Trapping it under one foot like a skilful soccer player, Joe would put on a good show of cranking the mike tightly onto a lump of iron, before whizzing the mike back along the floor in Fred’s direction. “Okay, thanks!” calls Joe, as the mike slid back to its rightful owner. With equal skill, Fred would grab the instrument, blow on it, and drop it back amongst his spanners. “Ta!” You can imagine the look of puzzlement and consternation on the face of the new arrival. Regards, Sam
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27/05/2020 01:50:29 |
Perhaps not of the same vintage as your Slocombe Barrie, but close. It was going for 10/- (ten shillings) second hand in about 1950 shortly after I started my apprenticeship. For years, both during my time in the toolroom and later, I used it mainly for small work on the lathe. Never as a ‘G’ clamp, and seldom swung around like a clog iron. As a college metrology exercise, various tests showed where it had worn. Almost at a forensic level, there were clear signs on the anvil and a section of the thread of it having been used for round stuff in the range of 0.3" – 0.5" diameter. An optical flat, applied to the anvil, revealed a ‘valley’ and ‘hills’ at roughly 45°, evidence of (my) holding it in my right hand from under the workpiece. Regrettably, my notes have gone the way of many. The micrometer is still in my toolbox. Sam |
Thread: Macro-photography |
27/05/2020 00:25:33 |
Not sure what happened to my latest post. However, I need to wake up. The cobbled-up slide-copier was described here ... Call it another of my Senior's Moments. "Must try harder!" Now where did I hear that before?
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26/05/2020 23:44:10 |
Another birdbath rescue, Raphael. This time it was a Fiddler beetle - Eupoecila australasiae. **LINK** Lots of 'free-style' swimming against a blue-glazed birdbath, it was difficult to follow. Fortunately, the camera has both an LCD and a viewfinder. Uncertain of its potential to bite or poison me, it is unlikely I would have lifted it clear with my finger. The image is a single-frame snapshot from a different video camera, a Canon Legria HF G40. I sold the Sony-HDR-CX405 when the far greater flexibility of the G40 caught my attention. It also sports the 58mm filter-ring thread and thus accepts a couple of my other bits. The latter were a part of the kit from the old digital Canon 300D I’d been using for years. More recently still were the two Canon close-up lenses. With a passion for close-ups and long before I bought the 300D, I’d been using its roll-film predecessor and a Novoflex bellows, which I still use from time to time. The electronics between the lens and camera, pass along a flexible printed circuit embedded in the folds of the bellows. Having the extra rack for camera positioning is very useful. To skew this topic slightly, it might be an idea to show my crude slide-copier cobbled together when I was copying some of my extremely old (50's) Kodachrome slides. It features a Canon f/2.8 - 100mm macro USM lens. Anyone interested? Sam
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26/05/2020 02:28:15 |
I forgot to mention ... Thank you Bandersnatch for the '3DStereo.com' **LINK** Nick, I can offer no extra help, but after years of on/off practice, I can squint and grab the images in seconds. It must be a special gift ... well not really. To everyone ... 'Good luck, and keep safe'. Sam |
26/05/2020 02:14:08 |
This picture has little merit in itself. It’s more about the way and with what it was taken. If I’m alert to their demise, I tend to rescue the few flying insects that have fallen into the birdbath. There has been the occasional bee struggling for her life and for which I see no threat. With their unpredictable nature however, wasps lose out. The ladybird presented no such threat that I was aware of. While it sat on my finger as a drying-out option, it was also a good opportunity for my wife to grab the relatively new Sony-HDR-CX405 Handycam. The camera specification boasts a 30x optical zoom and a digital zoom (extension) of unmentionable range. Here was a unique occasion to test the zoom. Unfortunately, in the brilliant Australian sunshine, it was almost impossible to see the image in the LCD. Focus was supposed to be both automatic and manual, although I can only recall being unable to stop the camera from grabbing a sharp image of the brick wall in the background. It should also have been easy to operate the camera with one hand while my other hand was preoccupied. It wasn’t. Struggling to keep the insect in frame while the camera preferred to focus on the background, in my haste to get the picture, I couldn’t remember which button to press or where it was on the camera. It took a smart woman to come to my rescue and between us … Success! There have been other specimens to survive the birdbath experience, but this will do for now. Sam Edited By Sam Stones on 26/05/2020 02:16:31 |
25/05/2020 01:30:35 |
Yes, I 'see' what you mean What a wonderful thread, and so much to learn. Keep it going Bandersnatch. Sam
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24/05/2020 23:16:34 |
Raphael, Until I scanned the Internet, I had only known of the cross-eyed method of unaided stereo viewing. This **LINK** explains various techniques including free-viewing which might work for you. For me, it doesn’t. My brain seems to have been exercised on too many occasions to only take a cross-eyed view of things. I've arranged this for free-viewing, and hope it works for you. Sam
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23/05/2020 23:26:16 |
Indeed, Chris. There's something special about contre-jour (back-lighting). Sam |
23/05/2020 02:28:49 |
Thanks Bandersnatch, The PCB was the most interesting thing I could grab before my curiosity and energy level began to fade. Never having seen them before, I’d guess the half-blinds in those Ritech glasses separate the left/right image pair and don’t send you cross-eyed?
Raphael, I like you suggestion that those dragonfly leading edge serrations may be … nature’s equivalent of vortex generators. I've wondered if they are a form of weaponry or a means of defense. There’s so much to learn from what has evolved, e.g. how some of the bones of birds are hollow, while being braced internally. In attracting other topics, I'm pleased to see this excellent thread is holding up. Great stuff, Sam |
22/05/2020 22:54:06 |
Very impressive results Raphael, and a smart move to use the slide from your mill. Now here’s another to add to your list. With a little more effort, you could try some stereo pairs. I wonder too if you’d need as many as 30 per pair. With my fascination for complex PCB layouts, here’s my one serious effort. Unless you are familiar with the method, unaided viewing can take a bit of practice. Both eyes need to be working, and if you can’t squint (i.e. turn your eyes in), it won’t work either. In addition, although it hasn’t happened to me, the method may make you feel uneasy. With the image pair as large as you can make it, AND your eyes positioned horizontal (parallel) cross your eyes while trying to align one of the larger components. Your brain should suddenly ‘lock’ the two images into one. Then, in the case of the PCB layout, it should begin to look like a 3D aerial view from a drone or similar. I’ve included the separate .jpg files in my album if you’d like to experiment with them. Our left eye will line up with the right, and vicky verka. I'm sure other members will improve on what I've written. If you want the original (Canon) RAW files you’ll have to PM me. Keep up the good work, Sam Edited By Sam Stones on 22/05/2020 22:55:15 |
21/05/2020 04:50:39 |
Please excuse my muscling in on your thread Raphael. Close-up photography can be fascinating. Having chosen this for my avatar, I have pondered over the colours. There are colour bands both distinct and diffused. Are they a result of different gases, different temperatures, and/or do they show limitations imposed by a stepped colour gamut within the image file? Sam |
21/05/2020 03:54:17 |
The rose, perhaps not quite MACRO in the accepted sense, was barely 2cm across. It sat about 30cm off the ground in a near abandoned shady part of the garden. The background was a not very inspiring old wooden fence, so it was an opportunity to open the file up in Photoshop. I couldn’t find a suitable background to slip in behind it so ‘all-black’ seemed an appropriate alternative. With a bit more jiggery pokery, I gave it a lift into pseudo 3D by hiding the edges of the frame behind the petals. There’s so many tricks you can do in digital photography, it’s becoming mind-blowing. Sam |
21/05/2020 03:21:15 |
Several years ago, I risked buying a couple of achromatic close-up lenses (250mm and 500mm) for my Canon Legria G40 HD camcorder. Although authentic Canon lenses threaded 58mm, I couldn’t be sure they would be fully compatible accessories in an optical sense, that was the chance I took. Later tests proved to be what I considered acceptable results. An early opportunity to test one of them came when I was fortunate enough to find this dragonfly to take home. Thinking it had died, I placed it on the nearest silver birch branch at a convenient height. As it happened, it was still alive and actually flew off later. It was early morning and perhaps cold enough to limit the creature’s movement but not mine. I dashed inside, grabbed the tripod and the 500mm close-up lens. I chose to run the camera on video, later selecting the single frames seen here. Head and shoulders? But what about the saw-tooth edges? What purpose do they serve? Any clues? Sam |
Thread: Macro rust spots. |
20/05/2020 22:34:47 |
This is my diversion from Raphael’s Macro thread which commenced here … **LINK** I have wondered about this pattern of rust spots. They are on the inside edge of the 1.5mm gauge plate marked CSt, see inset. Gauge plate has a probable carbon content of around 1.3-1.5%. The rest of the block is made up of several hundred stainless steel 'shims', marked SSt in the inset. The surface is rough, a result of the EDM wire cutting erosion. What puzzles me is why are the rust spots that shape, variegated in colour, and loosely distributed the way they are? Shouldn’t the rust appear uniform? By the way, the hole (2mm dia) at the bottom of the image was were they initially threaded the EDM wire. For reference, here's the block again ... Sam
Edited By Sam Stones on 20/05/2020 22:45:56 |
Thread: Macro-photography |
20/05/2020 22:10:31 |
Looking like a round solid, our brains tend to flip what we see with what we are more familiar, thus presenting a mind-confusing illusion. Sorry Peter, in reality, it is actually a hole through what remains of a sandwich of metal ‘shims’ after an EDM wire-cutting exercise. Crammed and riveted between two pieces of 1/16" (1.5mm) gauge plate (CSt) are several hundred pieces of thin 0.003" (0.08mm) stainless steel (SSt). Lying about over time (more than 30 years), the high carbon steel (gauge plate) has developed interesting rust spots. Rather than disrupt this thread, I’ll start another about the rusting. Sam
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20/05/2020 22:01:30 |
This continues to be a great thread Raphael !!! Thanks for your insights Dave. I’ve pondered for some time about how phone cameras are able to produce images with such amazing results. In the late 50’s I was ‘cutting-my-teeth’ on a Leica IIIf with three lenses and a document copier with three extension tubes. In those days, a resolution of 96 lines per millimetre was the sort of standard quoted. I have no idea how that relates to pixels. Perhaps someone here will explain? What at first is hard for me to digest is the amount of effort and technology which went into precision lens grinding, and how many elements were needed in the 50mm – f2 Summitar; seven from memory. Now we see a miniscule lens apparently producing similar resolution. Would any of these lenses be injection moulded? I can appreciate the scaled-down pixel size, but how are the lenses made with (I imagine) an essential high degree of accuracy? Not about macro, more about printing large from Nigel Danson’s phone camera images, is this ... Sam
Edited By Sam Stones on 20/05/2020 22:02:37 |
18/05/2020 23:20:49 |
But for the scale, this might even be the Grand Canyon. This was the thread **LINK** Oh, and the colours are wrong for the Grand Canyon.. That's a brilliant grasshopper photograph, Brandersnatch. Looks like flash from the side, with fill in from above? By the way, with this one (below) ... You'll see it when you believe it. It's a brain teaser. Regards, |
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