Broke the 2" objective lens on my overhead projector: Neumade C24LCN. Anyone out there have one or a source for one?
Question by Hubiewan | last reply
Hi! Im gonna try out this project, Telescope , as I know nothing about optic or lens function maybe someone could just let me know if I should go for a Tele-Auto 6.3/400 mm or a Sigma 70-300 mm F4-5,6 DL Macro Super. I asked the creator but as time runs out for me I hope this gives a faster response =) Thanks
Topic by Suizezem | last reply
Hi. Boatingman here. When I joined Instrucables several years ago, there was a post showing a fresnel lens salvaged from an old TV, then set up with the mirror from the same TV, and then set up with a set of collimating lenses. Now, of course, this didn't make an actual laser, but it did extend the useful range of the focal point and, thanks to the mounting system shown, could actually be aimed. I can't locate this "Instructable", so if anyone out there does have it (or if you have done something similar), could you please let me know. Thank you. Ed
Topic by boatingman | last reply
Hunting through the attic I found an old 35mm projector. I wondered what governs the field of view of the lens system - for this projector it is obviously about the size of a 35 mm slide but for my video projector it must be considerable bigger although the lens looks similar. (I know hat isn't a very scientific judgement!)
Question by rickharris | last reply
I recently got a set of marco lenses for my DSLR, an old E300. They are the simple kind, basically a magnifying lens that screws onto the the existing lens system like a filter. My first impressions of this simple and relatively cheap alternative to a dedicated macro lens in the 400$ range were quite good. But I also found some downsides and would like to know if they are a general thing to accept or a result of poor quality standards. 1. Although about 20% of the lens are unused (nothing at all visible when covering the outsides of the lens) there is some nocticable distortion happening. Especially the corner areas of the image when the object fills the entire picture appear to be slightly bend. Is that due to the marcro lens being a single and cheap system or a general thing with these marcro filter lenses? 2. It is quite hard to to get a clear focus even with F22 settings and good light. With the X4 lens it is not too bad and leaves about 8mm of totally sharp image before it gets blurry. But when using the X10 lens I often have troubles getting a sharp image of an object that goes less than 5mm into the background. Using a smaller setting, like f11 and only 1-2mm of the image is clear and sharp while everything in front or in the back of this area gets more and more blurry. Is this due to the marco lens affecting the focus? For example taking a full size shot of a rose flower is next to impossible if the entire flower should be be sharp - I would like to be able to get at least 10mm of totally sharp image when using f22 settings :( If this is a downside of cheap filter lenses then I already learned my lesson, but would like to know a bit more before saving money on a dedicated macro lens that I will rarly use...
Topic by Downunder35m | last reply
At work we have a ZING laser knockoff and SOMEbody "accidentally" walked off aaaand it caught on fire. Almost everything has been tried to clean it, even putting it in acetone in the ultrasonic cleaner, and the lens is still crap. Short of buying a £75 replacement lens what inexpensive methods could be used to return it to a near-original state?
Topic by The Ideanator | last reply
I have this LED torch, a luxeon 'MXDL' (next to a AA battery in the photo). It's a 3 watt LED torch (supposedly) running on a AAA battery connected to a joule thief of some sort (it has some sort of transistor, a capacitor, and an inductor), but it isn't that bright,( being about the same as a 3 5mm LED torch which has these lenses), but I still like it because of its compact size and light output. Anyhow, its throw is kinda poor, and I was wondering whether I could put a cheap lens onto it (from out of, say a camera's lens) to increase throw. Would it work? How would I go about it? P.S: I found these AAA li-ion batteries online, but I didn't even know that those batteries existed. If I put one of them into my torch, they'd probably increase brightness a lot, but because they are only rated at 300mah, I really doubt if it would be worth buying them. What do you think?
Question by .Unknown. | last reply
I'm trying to follow an I'ble posted by Patholio (fisheye lens, https://www.instructables.com/id/cheap-fisheye-lens/). He used an element of a 28-200 mm lens. I have disassembled a 28-80 lens, but the results are less spectacular even though the focal length at the low range (28mm) is the same. I can imagine that the elements of both lenses differ, hence the difference. Is this the explanation?
Question by bertus52x11 | last reply
Hello, Is it possible to make a pinhole lens for a compact digital camera? I mean an add-on; nothing that requires dismantling the camera. I've looked around on the internet and realise that it is easy to make a pinhole lens with a DSLR; I tried the same technique with my compact but the result is as shown. I don't mind experimenting further but I just thought that I would check if it is possible and worth pursuing ; and if not, why not? Thank you.
Question by FriendOfHumanity | last reply
My kodak easyshare mini camera fell 1m off a table onto a hard floor, while the lens was opened. now it won't close properly and the camera won't focus at all. we have tried gently forcing it shut and twisting the lens, etc can anyone help me or is my camera ruined?
Question by AussieAnglerGal | last reply
Question by tico381 | last reply
Do someone know how to make a kind of motorized optical zoom? it need to be cheap (mayB buying some cheap stuff at the dollar store (binocular some stuff like that)) (shorting all this means: I need to make a optical zoomer that i can control whit some button) thx Koax
Topic by koax | last reply
I have a Odis Spunkmeyer convection cookie oven, and it seems to me one could superheat air and blow it in with solar, perhaps a tube that would be more practical for heating just air then blowing the air into the oven. Is this just me thinking out of my butt or is this feasible?
Question by Sarah C J | last reply
I want to make the google cardboard VR, but I cannot find biconcave lens. Is there any household thing that contains biconcave lenses with about 45 mm focal lengh and can the spectacle lenses be used for this project? Also buying online is not an option for me.
Question by Ahtasham Ahmad Mohtashim | last reply
I'm looking for a way to build a cheap threaded lens hood for my video camera
Question | last reply
Would a magnifying glass/lens increase the amount of solar energy to a solar panel/cell? or would it just block the rays? i'm a bit confused because people haven't done it before and because people put glass (and silicon) in front of solar cells all the time.
Question by Houdinipeter | last reply
My old Minolta 35mm film camera has not been used in 10+ years. Time for a new purpose or recycle. What can be done with old lenses? I have several telephoto. Old 35mm camera bodies? Those are great ideas! I'm really glad I asked.
Question by ripperman2 | last reply
Hello, I recently bought an adaptor for my Canon 600d ( rebel 3 ? ) to allow M42 lenses to fit to it. That was fine but the adaptor is stuck on the camera. It is not cross threaded. I have tried using slip-jawed pliers really hard, but not as hard as I could because I was afraid of damaging something. There is a small hole in the front of the adaptor if I press that and turn it , the adaptor separates, so I stopped that method. Any advice ? If not , I'll just go with the pliers as hard as I can. Thanks
Question by FriendOfHumanity | last reply
I'm building a laser gun and I would like a lens for the laser to shine through. How much of an effect would this have and where can I find a lens? Could I salvage the one from my broken galaxy player's camera? Also, what would the effect be to feed the laser extra power? Right now, it runs off of three button batteries, like the cheap ones packaged with many things, but I would like to run it off of a battery bank with four AA batteries.
Question by metalshiflet | last reply
I'm building a UV(A) 365nm powerLED lamp and need to protect the leds without loosing performance. Does anybody know of a plastic to protect the led without blocking the uv, glass is to fragile (and blocks), it's for heavy use.
Question by Fonnie | last reply
So I'm trying to make a seven colored laser Spirograph, with lens' (that turn the beam into a crosshair for example) and I can't for the life of me work out how to make it work properly. I can design it so that I either have the lens or the Spirograph, but I cannot make it so that the Spirograph fits through the barrel of the lens thread. I think my best option might be to have two holes in the front of the device or use concave mirrors, what do you guys think?
Topic by 5225jackiechanman | last reply
Hi, I would like to create an almost parallel beam of light with an LED and a biconvex lens. Therefore I have to place the LED directly in the focal point. I thought of a setup with a PVC pipe with threading: I could glue the lens to one end and screw a cap onto the other. Then I would drill a hole in the middle of the cap and stick the LED through the hole. By screwing the cap back and forth on the PVC pipe I would be able to find the exact focal point and then fix the cap in place. There is just one problem: Lenses are either incredibly expensive or only available as sets. The only exception I found so far are lenses for google cardboard. They sell for just a few euros on ebay. Google cardboard lenses have a focal length of 45mm and different diameters, I would like to use a diameter of 25mm which is no problem. Now I wonder: Is the focal length of 45mm too small ? Will I be able to get an (almost) parallel beam of light out of this setup ? The LED is no ideal point light source. Originally I wanted to get f>80mm but that is really expensive. Anyone with experience on this kind of setup ? Tips you could share ? Can I get this to work, or will the approach be too unprecise.
Topic by mintwurm | last reply
I found a broken cell phone with it’s camera and wondered if the lens could be used as a microscope objective. Image A shows the lens and it’s mounting with the CCD. The back of the lens is shown. The lens is about 4 to 5 mm in diameter. The starters from florescent lights make good lens holders. Image B shows a starter along with my modifications to hold the cell camera lens. The starter tube has 4 slits along the length so it can be compressed to fit the turret of the microscope. Image C shows it mounted on the turret. Image D shows the resulting view of a feather. It’s quite bad. Image E shows, for comparison, the view through an ordinary 20x objective (.40 NA). Here are some more lenses that I tried: Lens from a discarded flatbed scanner..... Very good! Lens from a 8mm movie camera...... Fair. Lens from the laser pickup of a discarded CD player..... Almost worthless. To take pictures through the microscope, I used eyepiece projection with a wide angle eyepiece. The lens on the camera was set to wide angle and maximum aperture, with a remote used to trigger the shutter. The camera’s LCD was used to focus and adjust the image. The camera’s autofocus handles the rest. For even illumination, be sure to center the objective lens over the substage condenser.
Topic by ShutterBugger | last reply
I have seen somewhere a cut down digital camera rehoused in a wooden box. the thought strikes me- I have several redundant Olympus lenses could I successfully take a point and shoot digital camera, remove the lens, mount the camera body in a box and add my Olympus lenses to the front to make an exchangeable lens digital camera? I realize I would need to get the lens to CCD distance right but that doesn't seem to be all that difficult - I can engineer an adjustable mount if necessary. it seems a pity to have all these lenses and nothing to do with them. Opinions guys?
Question by rickharris | last reply
Five hundred pounds will buy you a work of art only half an inch across. Horror-fan Kevin Carter, 36, spends up to two days hand-painting colourful dye on to each lens with a fine brush. The result turns customers into zombies, mutants, gives them an eye with teeth, or mirror-finish eyes. For the connoisseur (or horror movie actor), there is the traumatised look... Daily Mail article with more images.
Topic by Kiteman | last reply
Is ebay a reliable source of LEDs? I bought a 3 watt LED off there once (http://cgi.ebay.com.au/3-X-POCKET-LUXEON-3-WATT-LED-TORCH-FLASHLIGHT-LIGHT-3W-/320514643442) and it had kinda poor performance...but I don't know whether it was because the torch itself was poor or if the fact that buying it from ebay was what made it bad. Any how, I'm looking for a 1 - 3 watt LED, and a (narrow beam) lens for it, and was wondering where I could get it all for under $10 (AU). WOuld ebay be a reliable choice?
Question by .Unknown. | last reply
I am currently using a home built 3'' refracting telescope, and want to build a shorter focal length eyepiece to get some detail for observing planets (lunar surface, rings on Saturn, more of the moons of Jupiter. The current setup uses a plossl eyepiece with about a 25mm focal length, giving 30 to 40x magnification, and allowing very clear viewing of the moon, and will pick out three of Jupiters moons on a clear night. Ideally I'd like a 5mm to 10mm focal length, for a 100 to 200x magnification. I've considered using the lens out of a DVD drive, which looks as though it could work, although I've only seen one example of it done before. I also have a selection of reasonable quality prisms and lenses about 1'' diameter, with focal lengths from about 2'' to 4''. So, how well would a DVD drive lens work, and are there any interesting designs that make an eyepiece with a focal length significantly shorter than any of its component lenses (in the same way the focal length of a plossl is about 1/2 the focal length of the lenses used). Thanks in advance for any help. (Would this get better response in the photography section)
Topic by The Skinnerz | last reply
Can anybody show me how to open the lens of pentax Optio LS1000. its lens stuck in the middle??? i've already open the camera but opening the lens part is risky...so i need some instructions to open the jammed lens...
Question by hotncold | last reply
I want some of these: http://www.9mmsfx.com/lenses.html But you need a prescription.
Question by bowmaster | last reply
I have acquired a couple of tv zoom lens from canon tv station cameras. Does anyone out there know of a way to turn them into a telescope. Or ad a camera back attachment. It seems like a waste tossing them out. The lenses are fine, btw I'm cheap!
Topic by cbucci | last reply
Just wondering if anyone has any ideas on how I can take clear plastic and totally black it out I am trying to create a shaped bokeh effect in a uv filter for a more permanent setting than cut out paper (what most people do). Now I bought quite a few for different shapes or if I mess up. Last night I printed out on sticker paper a heart and placed it in the center of the filter and used Krylon fusion (spray paint for plastic) on the filter. It took quite a few coats to get it so light never shined through. When It looked good I peeled of the heart sticker and half the paint went with it. An obvious failure. What im trying now is, I took that filter and scratched it up a bit and I found some super glue and just thinly spread some across the lens (to hopefully give the paint something to grip to) let that sit over night it was too late to paint. And today I am now putting a few coats on it and i plan to actually cut the heart shape out of the filter.
Topic by Ampix0 | last reply
Hello - I have a Nikon D40 with two lenses. The auto-focus works on one lens, but not the other. Suggestions I've already tried are to clean the lens thoroughly and clean the contact points. I'm not sure if I cleaned the contact points correctly, and I'd really like to know if anyone else has had this problem and been able to fix it. Thanks!
Question by brandegor | last reply
Not sure if this goes to the right section, if not, Im terribly sorry and tell me why I'm wrong so it doesn't happen another time. For a project I'm going to build a camera capable of taking picture (no duh) build with old materials. For my documentation process I was looking for anything that anyone already did, to inspire me and learn more about the building process. I found a lot of guides about pinhole camera and I wish to know if the process is the same if Im going to use a len. Naturally I would say yes and I would make the hole as big as the diameter of my len, or less and maybe I was wrong thinking that. The photography paper Im going to use is 10x13 centimeters and I would adjust the distance of the paper from the len. Also, I would like to know if covering part of the len (let say it's 5 diameter and 4 diameter is covered) is going to do anything to the outcome. The size of the len was never discussed in my lesson. Thank you.
Topic by sxdemon | last reply
Ever since I watched the first season of Stargate SG1, I've wanted one of those sweet little tactical periscopes that Jack o'Neill uses to look around corners to avoid Jaffa. The image is here, but it's just a prop! As far as I can tell, they either don't exist or are absurdly expensive or are just really hard to find. So I want to make one. I know some basic optics from working in a university laser lab, but we don't usually use lenses and such. I have played with simple two-lens telescopes and know that the ratio of the focal lengths is the amount by which an image is magnified. The corner would need to have a tiny prism in it. The problem I'm having is this: If I use tiny lenses, and a longish (~30cm) tube, the viewable area is ridiculously small. I would love to find a way to enlarge the viewable area I see in the eyepiece. Does anyone here know how this is done? At the very least I would like to know how to position the optics so that it seems like my eye is at the far end of the periscope. Maybe I could use a peephole lens to get a wider field of view too.
Question by laserjocky | last reply
I have made a simple version - using an acrylic sheet, heating, then pushing down a perforated metal sheet on top to create the 'bumps' Can anyone think of another way?
Question by sParekh | last reply
I have just started the optics section of my physics class and I was amazed to learn that one can use a simple magnifying glass to form a beam from an LED. Could this be used with a high power LED such as a 100 watt one, and then a beam expander (backwards to compress it) to form a laser beam of sorts. Obviously it wouldn't have a common frequency, but could one theoretically make a very high power, burning beam with this quite easily. I know from experience that holding your finger in front of a mere 10w led can get quite hot, so couldn't using a 100 watt led yield some awesome ant killing hotdog frying results? If not, how many beam combiners would you need to make it work
Question by seedorfj | last reply
I need a fish eye lens for an optical sensor. I have planned to get the lens from the front of a big (relatively) led from the attic. How can i do it without compromising on the focussing capability of the plastic lens ?
Question by sfsreporter | last reply