DIY = Do It Yourself

[stargazer]

Hello Dear Friends

This topic is for sharing Astronomical DIYs. Whether those you find in the net & astronomic sites or those you did them by yourself.

Hope you use & enjoy it:have a nice day:

[stargazer]

Everybody's Do-It-Yourself Dew Heater



by Alan M. MacRobert






[/URL][URL="http://media.skyandtelescope.com/images/dew_heater_m.jpg"]http://media.skyandtelescope.com/images/dew_heater_m.jpg (http://media.skyandtelescope.com/images/dew_heater_m.jpg)



A homemade dew preventer for a finderscope's objective. Six 25-ohm resistors, wired in series, will produce about 1 watt of heat when connected to a 12-volt power source. Tape the bare wires to prevent short circuits, and attach the ring as close to the glass as possible. Similar systems can be made for protecting other, larger optical elements.

S&T

If you're competent with a soldering iron and simple electrical components, you can make your own antidew device for a fraction of the price of a commercial unit.
Electrical resistors, available for small change at any electronic supply shop, make excellent customized warming devices for your telescope's dewcap, eyepiece holder, finder, and/or reflex sight.

First decide how much heat you need. The usual suggestion is 3 watts for an 8-inch Schmidt-Cassegrain corrector plate and 1½ watts for a finderscope objective or eyepiece. If your dew problems are severe you may need more. Fortunately, resistors are so cheap that you can experiment to find the minimum power consumption that works for a given application.

Electrical resistance is measured in ohms. To get a desired heat output in watts, the resistance you need is given by the formula


Ohms = Volts squared / Watts


where "Volts" refers to the voltage of the power source.

For instance, if you have a 12-volt battery and want 3 watts, you need 48 ohms of resistance. Eight resistors of 6 ohms each, wired in series, will do it. Resistors come in a limited variety of values, so you may have to settle for a little more or less than you want.

The resistors should be rated to handle the load you'll put on them. With eight identical resistors delivering a total of 3 watts, each puts out 3/8 watt of heat. So ½-watt-rated resistors should be good enough, though 1-watt resistors would provide a wider margin of safety.

The resistors can be taped into place with black rubber electrical tape. Get them as near the glass as possible. But be careful to ensure that no bare wire can touch metal; you wouldn't want a short circuit, much less an electrical fire.

How fast will the heater drain your battery? To find how much current it draws, use the formula


Amps = Watts / Volts


For example, a 3-watt heater running on a 12-volt battery draws ¼ amp. So a battery rated at 1 amp-hour will run the heater for 4 hours before needing a recharge.

If 120-volt power is available, obtain 6 or 12 volts with a small step-down transformer to run all the heaters you want indefinitely.

WARNING: It would be extremely dangerous to design a resistor heater, with its exposed wires, to run at 120 volts directly. Of course, you shouldn't mess with 120-volt power at all unless you're qualified. That includes knowing that anything using house current outdoors must be plugged into a ground-fault interrupt (GFI) circuit for safety — especially if you'll be touching a metal telescope while standing in wet grass! Plug-in GFI adapters are sold in hardware stores. And any power supply that plugs into a 120-volt outlet must be completely weatherproofed against dew.

From: Sky&Telescope

[stargazer]

CCD Eyepiece for Binoculars- Part 1



[/URL]http://www.instructables.com/image/FJ9MBBGFJXP7WCP/CCD-Eyepiece-for-Binoculars.jpg (http://www.instructables.com/image/FJ9MBBGFJXP7WCP/CCD-Eyepiece-for-Binoculars.jpg)


Have you ever looked through your binoculars and thought " I wish I could get this on tape" ? Well now you can. In this Instructable I'll show you how to build a cheap CCD eyepiece that will fit most binoculars.
You can use it with any camcorder that has a video input to capture whatever you can get a view on with your binoculars.


Step 1: Materials and tools



http://www.instructables.com/image/FHRQQHGFJXP7WNC/Materials-and-tools.jpg (http://www.instructables.com/image/FHRQQHGFJXP7WNC/Materials-and-tools.jpg)


40mm PVC tubing, 1.8mm wall thickness. Not cricital, inner diameter must be wider than binocular.
Badly centered threading tool in the back.*
6 nylon screws, 4mm.*


http://www.instructables.com/files/deriv/FXP/KNH3/FJXP7WNB/FXPKNH3FJXP7WNB.MEDIUM.jpg (http://www.instructables.com/files/deriv/FXP/KNH3/FJXP7WNB/FXPKNH3FJXP7WNB.MEDIUM.jpg)



Everything for a simple power supply for the CCD. Depends a bit on the module you can get.*
Round piece of perfboard. In the next steps I'll show you how to make this.*


Gather the following, but note nothing is critical. Here and there I'll tell you how you could do it differently.

Tools:

saw, soldering iron, pliers, electric drill with hole saw, sharp knife, 4mm threading tool.

Materials:

- 1 cheapo binoculars (mine cost me +-8 euros, but they are quite good.)
- about 12 cm of PVC tubing , inner diameter must be a larger (1cm is ok) than binocular diameter. (I used 40mm diameter, 1.8 mm wall thickness, thicker is ok too).
- 6 nylon 4mm 12..20 long screws.
- RTV silicone or other adhesive.
- 1 CCD camera module. I used what I could get, which was a module cheap B&W module intended to go in a security camera. It cost me <20 euros. If you have the possibility use a color module with a decent number of lines, as this will give you a better result in the end.

-Some electronic components to power and attach the CCD module. This really depends on the module you can get.
Mine needed 5V, so:
- 78L05 Voltage regulator
- 10uF 16V capacitor
- 10uF 35V capacitor
- 220 ohm resistor
- red 3mm led.
- 1N4148 diode for protection against power-reversal,
- connector to go to a wallwart
- cable with video connector that matches the camcorder/monitor/videorecorder you want to use.
- a piece of perfboard.

optional: AA-size battery holder and switch, if you want a portable power source.

I couldn't find the exact datasheet of the CCD module I bought (they didn't even have it in the shop), but here is a datasheet of one that looks just like it, and had the same connections.

Incidently, you could do this hole thing also with a gutted webcam and use a laptop to record what you see through your binos, while you're on the road.

Step 2: Construct the tube


http://www.instructables.com/image/FC3ZQWKFJXP7WOT/Construct-the-tube.jpg (http://www.instructables.com/image/FC3ZQWKFJXP7WOT/Construct-the-tube.jpg)


1cm long tube .*
cut out piece of +-1cm .*



http://www.instructables.com/files/deriv/FFA/8UCW/FJXP7WP5/FFA8UCWFJXP7WP5.MEDIUM.jpg (http://www.instructables.com/files/deriv/FFA/8UCW/FJXP7WP5/FFA8UCWFJXP7WP5.MEDIUM.jpg)


1cm long pieces fit nicely in 10 cm long piece.*
6 threaded holes , arranged in pairs 120 degrees separated, on one end of the 10 cm tube.*


http://www.instructables.com/files/deriv/F7Q/C009/FJXP7WP4/F7QC009FJXP7WP4.MEDIUM.jpg (http://www.instructables.com/files/deriv/F7Q/C009/FJXP7WP4/F7QC009FJXP7WP4.MEDIUM.jpg)



Easy adjustment. You can shorten the screws afterward so they don't stick out so much.*


Saw off three pieces of the PVC tube : one 10cm length, and two 1cm length. Remove burrs with knife.
Cut a piece out of the 1cm long tubes, so that if you push it together, it fits snugly in the 10cm long tube.

Take the 10cm piece, put 3 pencil marks at 120degrees on the circumference. draw lines along the tube on marks. put pencil marks at 5mm and 15mm from end of tube. Drill six 3.5mm holes.
Thread holes to 4mm using threading tool. Insert 6 nylon screws.
Actual dimensions depend on your binocular a bit, but take a look at the pictures, you'll see what I mean.

give it a try and fit the tube to the binoculars as in the picture.


Step 3: Assemble the CCD module




http://www.instructables.com/image/FB0AORWFJXP7WRC/Assemble-the-CCD-module.jpg (http://www.instructables.com/image/FB0AORWFJXP7WRC/Assemble-the-CCD-module.jpg)




http://www.instructables.com/files/deriv/FYQ/PPHT/FJXP7WS5/FYQPPHTFJXP7WS5.MEDIUM.jpg (http://www.instructables.com/files/deriv/FYQ/PPHT/FJXP7WS5/FYQPPHTFJXP7WS5.MEDIUM.jpg)




[URL="http://www.instructables.com/files/deriv/FYO/RSSL/FJXP7WRE/FYORSSLFJXP7WRE.MEDIUM.jpg"]http://www.instructables.com/files/deriv/FYO/RSSL/FJXP7WRE/FYORSSLFJXP7WRE.MEDIUM.jpg (http://www.instructables.com/files/deriv/FYO/RSSL/FJXP7WRE/FYORSSLFJXP7WRE.MEDIUM.jpg)



Select hole saw slightly bigger than PVC tube.*


..........

[stargazer]

CCD Eyepiece for Binoculars- Part 2




[/URL]http://www.instructables.com/files/deriv/FS0/RHIV/FJXP7WTX/FS0RHIVFJXP7WTX.MEDIUM.jpg (http://www.instructables.com/files/deriv/FS0/RHIV/FJXP7WTX/FS0RHIVFJXP7WTX.MEDIUM.jpg)


Then sand down until neat fit in PVC tube.*



http://www.instructables.com/files/deriv/F4S/LQD3/FJXP7WRB/F4SLQD3FJXP7WRB.MEDIUM.jpg (http://www.instructables.com/files/deriv/F4S/LQD3/FJXP7WRB/F4SLQD3FJXP7WRB.MEDIUM.jpg)




Don't forget to adjust the focus. Fix with silicone adhesive or something similar.*
Cable with video signal going to monitor or whatever.*


You want the CCD to be in the middle of the tube, therefore use a hole saw to cut a piece of perfboard a bit larger in diameter than the PVC tubing, then put a bolt through the perfboard and place it in the drill. Sand down on a file until it nicely fits the tube.

As already mentioned in step 1, the electronics depend heavily on the CCD module you have.
For my module, a 5V power supply was needed. I'm sure the world isn't waiting for another 78L05 schematic, but here it is, just in case.
The jumper labeled "gamma" on the CCD is there to switch between indoor and outdoor use.
Solder wires or connectors to the module. It's more or less up to you how you connect the module to the outside.

Try to get the CCD module as centered as possible on the perfboard, this will make alignment easier later on. Don't panic if you do not get it exactly in the middle: thats what the nylon screws on the tube are there for.

Next comes an important step: adjust the focus of the CCD. There's a small lens on top of it. On my module, I had to unscrew it almost completely to get it in focus correctly to a picture a few meters away on the wall. A drop of silicone adhesive keeps the lens in place.


Step 4: Assembly and Allignment




http://www.instructables.com/image/FCERWHTFJXP7WV8/Assembly-and-Allignment.jpg (http://www.instructables.com/image/FCERWHTFJXP7WV8/Assembly-and-Allignment.jpg)




CCD module rests on one of the short 1cm tubes.*





http://www.instructables.com/files/deriv/F6K/C027/FJXP7WV6/F6KC027FJXP7WV6.MEDIUM.jpg (http://www.instructables.com/files/deriv/F6K/C027/FJXP7WV6/F6KC027FJXP7WV6.MEDIUM.jpg)




Bright spot at beginning of alignment. Center and decrease distance of CCD to binoculars, a few mm at a time. *




http://www.instructables.com/files/deriv/FU9/SBXU/FJXP7WV5/FU9SBXUFJXP7WV5.MEDIUM.jpg (http://www.instructables.com/files/deriv/FU9/SBXU/FJXP7WV5/FU9SBXUFJXP7WV5.MEDIUM.jpg)




Almost there, beginning to see details. *

http://www.instructables.com/static/img/pixel.gif (http://www.instructables.com/static/img/pixel.gif)



http://www.instructables.com/files/deriv/FVT/RV93/FJXP7WV4/FVTRV93FJXP7WV4.MEDIUM.jpg (http://www.instructables.com/files/deriv/FVT/RV93/FJXP7WV4/FVTRV93FJXP7WV4.MEDIUM.jpg)




Done! Yes, it looks better on a TV, this amber monitor is real crap. *





http://www.instructables.com/files/deriv/FQM/U8WL/FJXP7WV3/FQMU8WLFJXP7WV3.MEDIUM.jpg (http://www.instructables.com/files/deriv/FQM/U8WL/FJXP7WV3/FQMU8WLFJXP7WV3.MEDIUM.jpg)


church tower +- 1km away. Not easy to hold the binoculars and take a picture of the screen at the same time. *



[URL="http://www.instructables.com/files/deriv/FQ8/431M/FJXP7WV7/FQ8431MFJXP7WV7.MEDIUM.jpg"]http://www.instructables.com/files/deriv/FQ8/431M/FJXP7WV7/FQ8431MFJXP7WV7.MEDIUM.jpg (http://www.instructables.com/files/deriv/FQ8/431M/FJXP7WV7/FQ8431MFJXP7WV7.MEDIUM.jpg)




RTV silicone adhesive. *
After allignment, second 1cm tube is inserted. You can also glue this if you want. *
While filming, you can still use the other eye. *


Alignment is not that hard, once you know how to do it:

Place the tube on your binoculars, try to get it more or less in the centered, by adjusting the nylon screws.
Insert one of the short 1cm rings inside the long tube, but not to deep yet, you want approximately 2cm between top of the CCD and the lens of your binoculars.
Power up and connect the CCD module to a monitor or tv. Insert the CCD module and press it against the ring. Aim at something outside. Make sure upfront that the binoculars are in focus with the object you are taking into view.
If you're lucky, you'll see a bright spot somewhere in the screen. adjust the screws until the bright spot is in the middle, then take out the module, push the PVC ring inside the tube a few mm further.
Insert the module again, The spot should be larger, an might be a bit of center. Center again and repeat, until you have a complete bright image.

At that point the distance from the CCD to the binoculars is optimal. Take it out, put some silicone adhesive on the edge of the perfboard and insert. Then insert the second ring. Done.

Now go film something interesting and don't forget to rate!

From: Instructables

[هانیه امیری]

Observing Chair


The amount of comfort that an adjustable height observing chair brings to a long night of observing is hard to put a value on. When your body is in a comfortable, stable position, you will actually see more. Long guided photographs are far easier to achieve. I started with the basic design of the Denver Observing Chair, then made a few modifications. This is a great, easy to build project that doesn't cost a lot. Assuming you already have all the tools, it shouldn't run you more than $35.




[/URL]http://up.avastarco.com/images/zfnrgejz8y65j3039naz.jpg (http://up.avastarco.com/images/zfnrgejz8y65j3039naz.jpg)




The biggest complaint people seem to have about this chair is that it tends to tip forward when the seat is low, so I added the board you see on the bottom. It extends past the front of the chair for stability, and is notched so that the seat-side upright fits in and doesn't slip. A latch hook is added to tie the upright to the bottom bar so that it doesn't come out of the notch when you pick the chair up to move it. The only bad thing about the bottom bar is that the chair will not sit stably on uneven ground. But, if your observing is done on a nice level pad, driveway, or deck, it works great. You might be able to add adjustable feet to make it work better on an uneven surface



http://up.avastarco.com/images/dgemgnw9x40ev3i3lpyt.jpg (http://up.avastarco.com/images/dgemgnw9x40ev3i3lpyt.jpg)




Originally, I used the stair tread material for the anti-slip surface that holds the seat in position. After just a few uses, this material came loose. I replaced it and it came loose again. Then I tried a new approach. I set my table saw blade at a 45 degree angle, and set the blade height so the teeth just barely rose above the plane of the table. Then I ran the board that makes the seat-side upright width-wise across the blade. I moved the board about an eigth-inch, ran it across again, and repeated this for almost the whole length of the board. It took a while, but the result was a nice non-skid surface to keep the seat in place. After applying a two coats of polyurethane, I think it will last the life of the chair, too. It also reduces the cost of the chair, and I think it looks better.


http://up.avastarco.com/images/em9pxcila95837vv1vf.jpg (http://up.avastarco.com/images/em9pxcila95837vv1vf.jpg)


One last addition: a hard foam garden kneeling pad to soften the seat. You can get these for just a few bucks at almost any store that carries gardening supplies. I didn't fasten it to the chair, so I can also use it to kneel on when I have to

The whole chair folds up nicely so that it is easy to transport.

From:[URL]http://www.shoestringastronomy.com/diy/diy.htm

[هانیه امیری]

Eyepiece Trays


I wanted a convenient place to put eyepieces, filters, and other small stuff that was close to the business end of the telescope so I wasn't constantly digging in my equipment case during an observing session. I used a white polyethylene cutting board that I bought at the local home improvement store for less than $10. This material is amazing. It is easy to machine with woodworking tools. It is easy to keep clean. It is friendly to your expensive equipment, and I think anyone can get professional looking results. The one tray straps to the pier as shown, has through-holes for eyepieces, and a milled out tray area for filters, etc



[/URL]http://up.avastarco.com/images/zjg72zayl6y7ywnkkv.jpg (http://up.avastarco.com/images/zjg72zayl6y7ywnkkv.jpg)


[URL="http://up.avastarco.com/images/eg9l7l4m8t8g5hav1uwf.jpg"]http://up.avastarco.com/images/eg9l7l4m8t8g5hav1uwf.jpg (http://up.avastarco.com/images/eg9l7l4m8t8g5hav1uwf.jpg).



From: http://www.shoestringastronomy.com/diy/diy.htm
(http://www.shoestringastronomy.com/diy/diy.htm)

[پیمان اکبرنیا]

these posts are very useful and practical and we have no similar posts like these in persian language. so if someone translate these into persian language, many people can learn and enjoy. could someone please translate these and post them in persian DIY topic? :D

[stargazer]

these posts are very useful and practical and we have no similar posts like these in persian language. so if someone translate these into persian language, many people can learn and enjoy. could someone please translate these and post them in persian DIY topic? :D

oh, thank you mr akbarnia for your attention. :whoow:(we are so glad for this attention:grin:)
ok it's good but if we do this after that anybody won't check english forum any more:pathead: so do you or other users have any good suggestions for making here more useful , active & of course make good & useful discussions????
:wink:

[هانیه امیری]

these posts are very useful and practical and we have no similar posts like these in persian language. so if someone translate these into persian language, many people can learn and enjoy. could someone please translate these and post them in persian DIY topic? :D



Thank you Mr Akbarnia. I agree with you...Ok, so we make a deal, you translate persian topics into english then we translate english to persian one
:دی :دی:دی:دی

Much to my regret, the english part of the forum is not active. Although we have some members that are good at english but they don't pay attention to english topics. If anyone have any ideas about activating this forum, share with us. we are single-handed and we need others to help us .we can discuss in these topics too. So we invite every one to join and help us
Good luck
:)

----------------------------------
oops, my post & stargazer's were sent at the same time :دی

[پیمان اکبرنیا]

Thanks for your attention. I know that we need more help for English topics and I try to help but unfortunately I think that I don't have enough English writing skills to patricipate (actually It takes too much time for me to write in English and I have many other responsibilities in the forum which takes a huge amount of time and energy
:melt:

the primary goals of English section are these two
(1)
Collecting good English articles for Iranian amatures which miss stargazer and amiri and other friends are doing it in the best way
:brigade.baka-wolf.c
(2)
Writing and translating good material and articles about Iranian astronomical groups, projects, scientists and etc for English readers

I think we should work better for second goal. This needs more help from our other friends In forum who I think have good potential to do this job
:have%20a%20nice%20d
again I thank miss Amiri and miss Stargazer for their extensive efforts
:wink:

[هانیه امیری]

Thanks for your attention. I know that we need more help for english topics and I try to help but unfortunately I think that I don't have enough english writing skills to patricipate (actually It takes too much time for me to write in english and I have many other responsibilities in the forum which takes a huge amount of time and energy
:melt:

the primary goals of english section are these two
(1)
Collecting good english articles for iranian amatures which miss stargazer and amiri and other friends are doing it in the best way
:brigade.baka-wolf.c
(2)
Writing and translating good material and articles about iranian astronomical groups, projects, scientists and etc for english readers

I think we should work better for second goal. This needs more help from our other friends In forum who I think have good potential to do this job
:have%20a%20nice%20d
again I thank miss amiri and miss stargazer for their extensive efforts
:wink:






Don't mention it, you are our professor. Sure you are right, I mean other members join these topics

The goals that you clarified, are certainly our aim of English Forum. I hope in the not too distant future we'll reach our aim but actually when we improve, that the others cooperate with us.

I believe by working in English topics , we can improve our skills of writing and reading in english, too. So it has so much benefits to us. After improving our skill of writing ,we can reach the second goal
Thanks Mr Akbarnia for your useful suggestion
:)

Ok dear friends let's join and help us
;)

[هانیه امیری]

Collapsible Tripod Spreader


I really liked the tripod that came with the Orion Sky View Deluxe, except for the spreader. It was a very nice tray that attached to a hinge on each leg of the tripod with screws and wing nuts. It was only easy to transport if the spreader was removed to allow the legs to collapse, but then it was difficult to put together in the dark without loosing a wing nut. I designed this collapsible spreader using some aluminum straps and strap hinges, with a hub cut from sheet aluminum. Now you just lift up on the hub, and the whole thing collapses together with nothing to unbolt. I can also set the tray on the spreader, with a locator pin in the center so the tray stays in place. Now it is far more portable, and much quicker and less frustrating to set up



[/URL]http://up.avastarco.com/images/1q75xfww4bulb2cpf4i1.jpg (http://up.avastarco.com/images/1q75xfww4bulb2cpf4i1.jpg)



http://up.avastarco.com/images/i050m06c0i4eh9n5i80.jpg (http://up.avastarco.com/images/i050m06c0i4eh9n5i80.jpg)




[URL="http://up.avastarco.com/images/10z898229vo71loiy92.jpg"]http://up.avastarco.com/images/10z898229vo71loiy92.jpg (http://up.avastarco.com/images/10z898229vo71loiy92.jpg)


From:http://www.shoestringastronomy.com/diy/diy.htm

[هانیه امیری]

Caring for Your Optics




Any telescope or binocular that you use for astronomy, no matter how humble it may be, deserves the best care you can give it. Much of the time you’ll be using it right at the limit of its capabilities, and when you’re trying to see very faint objects or fine detail, little things make a big difference




Then again, life is full of imperfections, and there’s no point fretting about them. Every telescope gets dirty. Dirt on lenses or mirrors scatters light, making dark skies less dark and bright objects less crisp — but not nearly as much as you probably think. The right attitude toward optics means knowing when to be vigilant and when to relax




The first tactic against dirt is defensive, and this is when you should be vigilant. Keep the lens caps on when the instrument is not in use. If it’s missing a cap, make your own; a shower cap, or a plastic bag or dishcloth held over the front of the tube by a rubber band, works fine. As for the eyepiece holder, a plastic canister for 35-mm film fits the standard 1¼-inch focuser size. So does a wad of cloth




I store my two reflectors with their main and secondary mirrors both facing somewhat down. That way dust won’t settle on them in storage. Eyepieces should be capped on both ends or kept in plastic bags or small plastic food containers. Telescope retailers sell cheap, durable cases to store and protect eyepieces



[/URL][URL="http://up.avastarco.com/images/hlpeofjx631ie6hy9joz.jpg"]http://up.avastarco.com/images/hlpeofjx631ie6hy9joz.jpg (http://up.avastarco.com/images/hlpeofjx631ie6hy9joz.jpg)





Never touch the surface of a lens or mirror. The acids in skin oil can attack optical coatings over time. If you do leave a fingerprint on, say, a binocular lens, clean it off using the method described below



So much for vigilance — now to relax. Dirt happens, and in moderate amounts it has amazingly little effect on performance. In his book Star Testing Astronomical Telescopes, Harold Richard Suiter analyzes the effects of dirty optics in full mathematical detail. His conclusion? “The maximum amount of dirt [that a perfectionist] should tolerate on the optics is about 1/1000 of the surface area, the size of a single obstruction about 1/30 of the diameter.” In other words, on a 10-inch-diameter telescope mirror you can have as much dirt as in a completely opaque blot a third of an inch across. That’s quite a lot of crud to have no effect at all



“Don’t decide to clean mirrors on the basis of shining a light down the tube at night,” advises Suiter. “All mirrors fail such a harsh inspection.” After you’ve done what you can to prevent dust, ignore it



There’s a good reason to ignore dirt, aside from reducing the things to worry about in life. A dirty lens or mirror can always be made clean, but a scratched one is scratched forever. Cleaning causes tiny scratches, or sleeks, if you don’t do it right, and maybe even if you do. A few sleeks don’t matter, but a lot of them will. So clean your optics rarely

But if things get really bad and you decide a cleaning has to be done, I will describe how to do it, in the next post


To be continued.....

[gandom]

thank you honey for this useful topic

I read the last post and it makes me to ask u one question:
about the cleanin' lenses and mirrors of a telescope the passage just explained about how sensibility of the mirrors and lenses are
but by what kind of matters we can clean the surface of a lense or mirror?
thanks alot!:)

[هانیه امیری]

thank you honey for this useful topic

I read the last post and it makes me to ask u one question:
about the cleanin' lenses and mirrors of a telescope the passage just explained about how sensibility of the mirrors and lenses are
but by what kind of matters we can clean the surface of a lense or mirror?
thanks alot!:)



Thank you dear gandom for your attention
:)
I'm so sorry, I forgot to write that the post will be continued

I hope you'll get your answers in the next posts
:)

[هانیه امیری]

Cleaning Lenses


The quick and easy way to dust eyepieces is to lay a finger across the eye end (without touching the glass!) and suck air under your finger past the lens. (This moves the dust from the eyepiece to your lungs, but every astronomer knows which is more important.) The job takes about one second.
If that doesn’t do it, the traditional method for dusting optics is to brush lightly with a camel’s-hair brush. Sold in camera shops, these brushes have soft bristles with minimum tendency to scrape grit against a lens. Brush very lightly. Store the brush in its container or a plastic bag



[/URL]http://up.avastarco.com/images/e3qdjv6mnvdx9s6fiy.jpg (http://up.avastarco.com/images/e3qdjv6mnvdx9s6fiy.jpg)



Camera shops also sell cans of compressed gas for blowing dust off lenses. Be careful with the kind that use liquid propellants; these have a reputation for spitting onto the glass and leaving a residue if the can is tipped or shaken in use. Blowing (instead of sucking) with your own breath is also likely to leave spit marks


For tougher dirt or stains, various lens-cleaning solutions are available. Good ones are pure isopropyl alcohol or methyl alcohol (methanol), available in drug stores and hardware stores, respectively. Standard, diluted isopropyl rubbing alcohol works well too and is easier to find, but avoid alcohol preparations with other ingredients that may leave stains. Camera shops sell lens-cleaning fluids such as Crystal Clear, which is pure methanol, but you can get methanol much cheaper in a hardware store. Also available are “lens pens” with a soft, retractable, solvent-impregnated cleaning pad


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You’ll need a soft, grit-free wipe. A well-washed piece of pure cotton cloth works well. Moisten it with the fluid and swirl the fluid gently across the lens, applying no pressure. If necessary, rub dry with a fresh piece very gently. Don’t drop liquid directly onto the glass. It’s liable to seep around the edge of the lens into the cell and carry dissolved grime onto interior surfaces, staining them


Eyelash and fingerprint oil may discolor coatings permanently if left on long enough. But such stainsare only cosmetic, eyepiece manufacturers insist, and should have no detectable effect on performance.
If problems develop inside the eyepiece, it’s best not to take it apart. You are almost certain to tilt and jam (“cock”) a lens element, and if you try too hard to uncock it, the edge will chip. Instead, call the manufacturer and ask about a professional cleaning


The big front lenses of refractors and mirror-lens telescopes should not be taken out of their cells except by an expert. Again, the danger is cocking and chipping the glass — or not re-assembling everything exactly the way it was! Big lenses can be cleaned right in place the same way as small ones, by using more time and fluid


To be continued.....

[هانیه امیری]

Cleaning a Mirror

To clean the mirrors in a reflector telescope, you’ll need to be confident about taking the telescope apart and putting it back together again — and about collimating the telescope (aligning the mirrors) once it’s back together


How do you know whether your mirrors need cleaning? It’s simple: if you’re asking the question, they don’t! Leave the mirrors alone unless they are so obviously crudded up (probably due to careless storage) that there’s no question


If you do go ahead, here’s the cleaning procedure.
Undo the screws attaching the main mirror’s cell to the back end of the tube. Reach in the back and gently pull out the cell with the mirror inside it. Unscrew the clips holding the mirror in, and push the mirror out from the back without touching its shiny surface


You’ll also need to remove the holder for the small secondary mirror inside the front end of the tube, and then get the secondary mirror out of the holder



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The first and most important cleaning step is to remove all grit correctly.Ordinary house dust contains bits of rock powder, and rubbing this stuff against glass (or, actually, against delicate optical coatings) causes sleeks. So you’ll need to get rid of grit without rubbing

You’ll need the kitchen sink, two towels, liquid detergent, a bottle of distilled or demineralized (“de-ionized”) water (available in drugstores), and a package of sterile cotton (if it’s sterile it’s more likely to be grit free). Wash out the sink, rinse it well, and lay a folded towel on the bottom. Take off any jewelry from your hands and wrists. Put the mirror face-up onthe towel, and with the drain open, blast the mirror’s surface with room-temperature water for a few minutes. This will remove most dust and grit safely




http://up.avastarco.com/images/yvbh6qnvn8e1easxyn7.jpg (http://up.avastarco.com/images/yvbh6qnvn8e1easxyn7.jpg)
From left to right: The safest way to remove grit from a telescope mirror is to blast the surface with tap water. That may be all you need to do. If dirt remains, swish the surface lightly with clean cotton in lukewarm water and detergent. Rinse with tap water, then do a final rinse with distilled water (to prevent water stains). Set on edge to dry. You can draw off remaining drops with the corner of a paper towel.





Turn off the tap and give the mirror a final rinse with a slosh of distilled or demineralized water. This will leave no mineral deposits when it dries. Stand the mirror on edge (on a folded towel to prevent slipping) and let it dry. You can draw off stubborn water droplets carefully with the corner of a paper towel. If the mirror looks reasonably clean, quit while you’re ahead. You can’t scratch a mirror you haven’t touched.


If it’s still cruddy, there’s more here than just surface dust, so you’ll need to go to Plan B. Plug the sink, put the mirror back in on the towel, and fill the sink halfway with lukewarm water. Add a squirt of liquid detergent and let the mirror soak for 5 or 10 minutes. Then, holding it underwater, swirl it around for a last chance at rinsing off loose grit.
Take a wad of cotton and, starting at one edge, swab the mirror in one direction, applying no pressure beyond the weight of the cotton itself. Grit is less abrasive wet than dry, so do this step under water if you can


Turn the cotton over in a backward-rolling motion as you go, so that as soon as a part of it rubs the surface, that part is carried up and away from the glass. Throw out the wad when it has been turned completely. For a big mirror, the job may take a lot of cotton


It’s good to work in complete silence. If you make sleeks, you may actually hear them! If so, stop and proceed to the rinse.
Drain the sink and run lukewarm water over the mirror for a minute. Finish with a rinse of distilled water, and tilt the mirror on edge to dry. Repeat the process with the small secondary mirror


If you’re ever faced with a truly ghastly cleaning job — for instance, if you’ve just rescued a $2,000 telescope from 10 years of moldy exile in a relative’s basement (something we get calls about all too often) — call the manufacturer and ask about a professional makeover. It may not come cheap, but it’ll be cheaper than a new scope


The right attitude is to be vigilant about preventing dirty lenses and mirrors — and then forget about them. Perfectionists are never happy, but astronomy should be fun. After all, what matters is not what you see on your telescope, but what you see through it


From:[URL]http://www.skyandtelescope.com/

[هانیه امیری]

Adding a Webcam to your Telescope


Many of us have wanted to capture that great lunar or planetary image to share with friends, or just use as wallpaper on a PC. There are plenty of FAQ on the Web covering image processing but this project goes back to the basic steps; how to get the image in the first place

What you need:
A webcam, many sites talk about the ToUCam but I have found the old (2003 vintage) Logitech QuickCam is an excellent starting point. Have a look on eBay and you will quickly find one close by; the one used in the FAQ cost me $12.50. Make sure it has a CCD sensor, not the much older CMOS type

Small hand tools

(A rubber doorstop (No kidding, keep reading

Some tape

A laptop or PC close to your telescope

AVI software that comes with the camera or can be downloaded from the manufacturer’s website.


Modify the webcam


What we are after is the CCD image sensor from the camera, the actual chip that does the conversion of the analogue signal (the light) into the digital pulses that make up our final image. So first, some surgery:



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This is our starting point. To get it open, you may be able to unscrew the housing or you may have to cut it open. If the latter is needed, I have found a fine coping saw blade or better still one of the small tools by Dremel work very well. The main thing is to get it open without damaging anything inside.
Once that is done, we have something like this:


http://up.avastarco.com/images/n48gcfalnxhn7tnqinmi.jpg (http://up.avastarco.com/images/n48gcfalnxhn7tnqinmi.jpg)


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In this particular camera, we have two surplus connectors for the shutter release and the microphone. All we want is the main board itself and the attached CCD chip.



Remove the board from the shell and unclip any extra connectors, then remove the lens that is fitted. On the Logitech cameras with is a rather crudely machined plastic screw thread, just unscrew until it comes off

http://up.avastarco.com/images/09cf5gdky0a7cipplhey.jpg (http://up.avastarco.com/images/09cf5gdky0a7cipplhey.jpg)


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In the photo above you can clearly see our prize; the CCD chip and associated electronics

...To be continued

[هانیه امیری]

The next step is to put is all together again so the electronics are protected and the whole unit is a bit more robust. Since the camera we are using here has a screw together housing that was simple


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Now for the next bit, mounting the camera to the telescope.


Mount the modified camera to your telescope



For lunar or planetary imaging, we are using the prime focus of the scope only, sometimes using a 2x Barlow. This means that we need to mount the camera directly to the focuser and that is where the rubber doorstop comes in


What we need is in fact the mounting block for the doorstop as it just so happens that this piece of plastic is a perfect fit for the focuser on my telescope. Of course you can substitute anything you like or have handy here; a 35mm film can is a good choice, some small food container would also do.



Drill a hole in your chosen mounting block to suit the size of the CCD chip and still leave enough plastic in place for a secure mount. I chose the quick and dirty method of electrician’s tape to secure my camera though you may decide to be a bit more fancy.



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http://up.avastarco.com/images/uidj05qarrknjeb02p3.jpg (http://up.avastarco.com/images/uidj05qarrknjeb02p3.jpg)


Note the CCD is clearly visible in the last photo.
Finally, time to mount the camera to the focuser.
On the left below is the camera mounted to my f7 / 130mm telescope. On the right is the whole setup



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http://up.avastarco.com/images/hwknrhwplzh8usqwpmqx.jpg (http://up.avastarco.com/images/hwknrhwplzh8usqwpmqx.jpg)

http://up.avastarco.com/images/m0u1hwqktt1qrk73g25.jpg (http://up.avastarco.com/images/m0u1hwqktt1qrk73g25.jpg)


One nice thing about the Logitech cameras is that they come with about 2 metres of USB cable making connection to the laptop easy.



Now you’re all set up, start following instructions for capturing and processing images.

From:[URL]http://www.iceinspace.com.au/home.html