Under Israeli Skies

Pimp My Telescope -- Red Dot finder

2008-03-10T03:52:00.000-07:00

I managed to pick up a simple red dot finder, actually it is simpler than I thought and I think I can make one out of a laser pointer and some optical glass etc.

Pimp my Telescope - components list

2008-02-20T00:13:00.000-08:00

Parts to make/fabricate

Bearing Box

The box, 4 sides about 7" long by 3" wide
Bearing disks, 120 mm diameter, (double thick, apply laminate)

The Fork

Bottom Disk, 10" Apply Laminate
Fork Arms 8" high (Double Thick, apply teflon)

The Base

Tripod top disk, 10" (Teflon on top)
Legs, 4 foot, round edges.

Building the Dob-like mount

2008-02-18T02:19:00.000-08:00

For the Bearing Box:

1 sheet HVHC plywood (3/8 should do it)
1x2's for the legs (3)
Teflon (On order)
Ebony Star (on order)
Varnish/wood finish

Tools

Jigsaw
Router
Sander
Square
Clamps (have a few more would help)
Circle Jig

Modding the telescope (ETX-127)/ AKA PIMP MY SCOPE

2008-02-17T22:25:00.000-08:00

OK so I have a meade ETX-127 Optical tube that I picked up used. currently it has a orion 9x50 Finder which Is pretty nice but poorly placed. In addition the scope is currently sitting on a tripod head that was really made for a view camera. and while it works well with a view camera it kind of sucks for a telescope.

SO some changes, I would like to do 1 and 2 and maybe 3 in the next month.

Build a dob style alt-az mount, and maybe a new wood tripod
Move the current finder to the structure of the mount (see #1) (may need new finder bracket)
Add a Zero Power Finder
Add Binoviewers
Green Laser Pointer?
Pair of 13mm Naglers

Photography projects

2007-12-25T03:42:00.000-08:00

I think with the equipment I have now (save what I just wrote about in the last post) I can do most of the things I want to do. I have some ideas for stuff involving flash that will have to be put off until some future point, but I think I can do the projects I'm working on now at least to some extent with the cameras I have. I think a normal lens (Which is what most of the cameras have) will work for all of these.

Flowers: Sinar with the "Flower Tripod" Just have to wait for the flowers to bloom, I will probably also have to find a large piece of cardboard to lie down on while working.
Milky way, Round 1: Pentax or Rollei with Barn Door, next summer mostly
Landscapes, Sinar just need to find the time, and get my car back. I would like to drive down the Allon road over Passover to take these.
Moonscapes, Full moon in the desert, can use any camera, normal lens will work fine.

Equipment to aquire in the short term

2007-12-25T03:35:00.000-08:00

"Flower Tripod" Will be just two boards screwed together with a screw to attach the camera. I may have to buy the machine screw and a few screws to build it. Should be able to salvage the wood. Total cost less than 50NIS.
Need to buy

Machine screw to mount camera
Some wood screws (May have)
Wood glue (may have)
1x4 board , about 3', may be able to find
Loops for tent pegs (Strapping, 12")

Barn Door mount/ bent bolt.
Needed to buy (See sky and telescope)

Wood, (See above)
Some eletronics (current regulator, Pot, Resistors, LED, breadboard)
gears (2 same tooth count)
extra finder bracket ($12)

New Telescope

2007-12-25T03:33:00.000-08:00

I picked up a Meade ETX 127 MCT telescope, well just the OTA. I attached an Orion 9x50 finder and put in some eyepieces that I already had. So far mostly been looking at Luna (as I didn't have that finderscope)

Also recently aquired a Carl Zeiss Jana 300mm F4.5 Tessar lens for the astrograph.

Building a small ball scope

2007-10-12T02:35:00.000-07:00

So I have a 114mm F8 Mirror with a secondary and spider, I have been wanting to turn this into a telescope for some time (and will do so if I ever have any money). I would like to build a small ball scope with it.

Needed:

Sheet of plywood (1/2 inch should be fine)
3/4 Al tube (enough for 3 trusses)
Tube Cutter
6-7" Sphere
Random fasteners
Some Lead Shot for counter balance
Wood Varnish
8cm fan

Large format Astrograph

2007-10-08T23:50:00.000-07:00

Plans for a 4x5 astrograph box camera.

Framework of camera 1/2" Plywood inner painted flat black with velvet ribbon light traps.

Front with current 150mm F5.6 Lens on lensboard.

Back Ronchi Screen 100LPI printed on transparency film over glass.

Ensure that film plane and the glass are in the same spot. Focus with Ronchi Screen, then check the focus with B&W film.

Focus travel +/- 1".

Film and Tracking

2007-09-09T09:31:00.000-07:00

It looks like a tracking platform (AKA Barn door mount) will be on my to do list for the near future. I want to get a GEM but for now its on hold due to lack of cash. This should at least allow me to do 2-3minutes on the K-1000. This should be good for a few rounds (or at least until I use up the 6 rolls of Provia 400F that I have)

Longer term I want to get a GEM so I can track longer and guide.

For Large format film I'm no deciding between Provia 100F and Kodak E100G.

The Moon and venus at sunset

2007-08-07T09:23:00.001-07:00

Milky way project -- Test Image (take 2)

2007-08-06T03:54:00.000-07:00

Milky way picture, same as the last one, but a better scan. (Click for larger)

15s Fuji Provia 400F, pushed 1 stop, on a tripod. with a 50mm Normal lens at F2.0.

Milky way project -- Filters

2007-08-05T11:54:00.000-07:00

Deap Space objects including the Milky Way in general are pretty low contrast objects. So filters seem to be a good idea if one can be found to pass the correct parts of teh spectrum. It appears that a Kodak 3x3" (75mm) #32 Magenta Special Color Effect Wratten Gel Filter
will do the trick. According to various sources I found it will pass 320-500nm and 600nm plus thus removing much of the green parts of the spectrum. The green range includes a lot of light polution and sky glow from O2 in the high atmosphere. This should bring out milky way nebulosity and structure though it may reduce stars a bit.

I need to figure out what the best way to attach one of these to the camera is, but I expect its not too complex.

Milky way project -- Focus

2007-08-03T06:17:00.000-07:00

The critical factor in the milky way photo atlas will be getting the best possible focus out of the camera. At F5.6 the ground glass is not that bright, but 0th magnitude stars can be seen with help from the loupe. The nice thing is a star forms a clean point at proper focus. So assuming that the film plane and the ground glass really are at the same place (Something to check) it should be possible to establish a clean photo.

Film buckling may be a problem, so a vacuum back film holder will be useful. (see link). At least 3 film holders would be a good number to be able to work in the field. Even that will require a changing bag. Quickloads might be better.

http://www.deadbread.com/crumbs/vac.html

Milky way project -- Film Choice

2007-08-02T12:03:00.000-07:00

After camera selection for the Milky way project the next more important thing will be film choice.
The "perfect" astro film would combine a few characteristics:

No reciprocity failure
Fine grain
sensitive to H-Alpha at 656.4 nm
Sold in 4x5 format
Fast
E-6 positive development
Handles push processing

However there is as far as I know no such film. Fuji's provia 400F is gets 1,3 and 5, and not bad on #2, but is not sold as sheet film, so that kills that idea. So what is left

Provia 100F
Astia 100F
Velvia 100
Velvia 100F
A Kodak film

It looks like Velvia 100 might do a bit better on the red, Astia has a bit finner grain, and I think Provia will push better. I think they will all be fine on the other points. Kodak's datasheets are not as easy to understand as Fuji's, so I will stick to Fuji.

I may have to buy a few rolls/boxes and take them out to test and see what does best.

Milky way project

2007-08-02T06:46:00.000-07:00

In the early 20th century Astronomer EE Barnard composed a photographic atlas of the milky way, this work was done at the Lick observatory in California and was at the time a rather technical venture. However with the advances in film and camera technology it should be possible to take similar pictures today with amature level equipment.

With modern films such as Fuji Provia 400F it is possible to get quite a lot of milky way detail in as little as 15 seconds at F 2.0. With an equatorials mounted telescope and a camera mounted piggy back wide fields can be captured of much of the northern milky way, from Sagatarius up across to Cassiopea and down into the winter sky. This will take many sessions probably over a course of several years.

The first question is what type of camera to use:

The Options:

* 35mm (Pentax K-1000)
Advantages:

* Easy to use
* Easy to get lens for
* F2.0 Lens
* Light weight
* Film is reasonably cheap

Disadvantages:

* Small Negatives
* 50mm Lens leaves a pretty small plate scale

* 120 format, Rolleiflex F2.8 80mm
Advantages:

* Film is larger
* High quality optics, probably can be shot at F2.8 or F4.0
* Film is still not very expensive
* Not too heavy

Disadvantages:

* Camera is flakey and needs repair
* only one lens (but at least is a really good one)

* 120 Format Pentacon 6 or the like with 250 mm lens
Advantages:

* Same size film as the Rollei
* Long lens will bring out more small details,

Disadvantages:

* Unknown mechnical and optical quality
* Would have to buy camera (1200NIS or so)
* Weight?

* 4x5 format, Sinar F1
Advantages:

* High end 150mm APO lens
* 150mm Lens will bring many smaller details above the grain of the film
* 4x5 film is much bigger allowing for a lot of detail

Disadvantages:

* Provia 400F is not made in 4x5 would have to use Provia 100F
* Lens is only F5.6, so exposures would have to be in the 5-10min range
* Camera weight
* Camera flex could be a problem
* Film flatness could be an issue, with luck quickloads would fix this, or if not we can build a vacuum back

For now I plan to start trying with the Sinar, this may get swapped out for a flatbed camera, however if the project can be made to work with a LF camera the result will look amazing.

Milky way project -- test image

2007-08-02T05:53:00.000-07:00

This is test shot of the milky way near sagatarius. I think the double stars are due to a bump of the tripod. The shot was taken bya 30 eyar old Pentax K1000 camera with Fuji Provia 400F film pushed one stop, 15s on a fixed tripod from outside Mizpe Ramon Israel.

Orion With labels

2007-07-08T09:17:00.000-07:00

Fuji Provia 400F, 15S at F2.0 ( I think)

Best Observing in a long time

2007-06-21T13:12:00.000-07:00

Ok so sometimes Insomnia pays off. I took my binoculars out and had a very nice time. I spent most of my time
touring around scorpius and sagatarius. Nice view of Jupiter and a few moons. Spent some time viewing M7, as well as a globular (not sure which one) and a gassious nebula. (M20?) I also saw an amazing fireball. One of the best ones I've seen. It went from Lyra or Aquila all the way to Ursa Major. with a pretty well defined head and a very long tail. I also took the binoculars off the tripod and looked around Lyra and the summer triangle. To bad that that the ring nebula is not within what you can do with my binoculars.

This was all out the back and side of the house with my celestron 15x70 skymasters. If anyone wants an intro astronomy tool these are great. Not the fanciest thing in the world, and not really great for planets. But for under $100 its about the best you can do, assuming you can find a heavy duty tripod.

Mirror in hand

2007-05-20T02:20:00.001-07:00

I have my 114mm F8 Mirror. I should be able to start building the scope around it in the next few days. I'm going to find a few feet of sonotube after work. Then to get started working on putting the thing together next week.

Low cost small telescope project

2007-05-07T02:09:00.000-07:00

One of my current goals for this blog is my 500 Shekel telescope project. I would like to build a number of small (4.5"/114mm) reflecting telescopes for as little as possible. My current goal is that it should be about 500 Israeli Shekels including 1 eyepeice (A 25mm Plossl) and the main optics etc. 500NIS is as I write this about $125 USD, and this should include the cost of importing the optics from the USA. I don't know if this will actually be a price goal that can be hit, but its worth trying.

So why the blog? It is my hope that if other people in other far off corners of the world would like to build a telescope (or a bunch of scopes). that this blog might prove some useful ideas.

If anyone out there ever does use my plans or ideas, please let me know. Or even post a picture of the scopes you may build from them.

Cost of Plywood

2007-04-25T01:29:00.000-07:00

A co worker has just informed me that a 4'x 8' sheet of plywood costs about 100NIS. If cut carefully this should be enough for 3 telescopes. Now to find out about PVC for the focuser.

Telescope Components

2007-04-19T23:14:00.000-07:00

Ok in addition to the optics, to build a scope we will need the following sections

Scope Tube (Sonotube)
Spider and Secondary Holder (wood and metal for the spider)
Mirror Cell (Plywood, some bolts and something to allow them to be adjusted)
ground board (Plywood, with furniture feet)
Mount (More Plywood)
azimuth bearing (wood or PVC)
Focuser (PVC)

Tools needed:

Circular saw
Router
Drill
Jigsaw
Some jigs for various things

Other things needed

epoxy
bolts
Nuts
1" Dowel For secondary holder
metal strapping
Cork shims
teflon

Telescope factory, copied from my LJ

2007-04-19T23:10:00.000-07:00

OK I have had this idea for a while but the strong shekel and the fact that I have found some decent sources for optics in the USA makes this seem like a good time to put the idea out to those in Israel, would anyone be interested in finding some time this summer to build telescopes.

In terms of cost this is what we are looking at

Primary Mirror $33 (4.5" F8, good for a small starter scope), secondary included
Plossl Eyepiece $25 each, I would suggest at least a 25mm, but it may be worth getting a few

Here is the thing, if you just order the primary mirror shipping will be about $23 to Israel, however according to their shopping cart if we order 3 mirror sets and 3 eyepieces then shipping only goes up to about $40. The upshot is that if we want to build 3 scopes then the cost would be about $70 each for the optics. We would have to fabricate a bunch of stuff locally (Mirror cells, Spider, Focuser, scope tube & dobsonain mount) but none of that is impossible. Best guess would be about 300NIS for optics, and at most 200 NIS more for everything else. Maybe less.

I'm still working out ideas for finderscopes

If anyone is interested please let me know. Power tools would be a plus! Routers and circular saws seem to be the things we would need the most.

I would be happy to also show people how to find star charts on the web.

Feel free to pass this on to anyone you know who might be interested.

In terms of what can be seen with a 4.5" Scope

The Moon, in great Detail
Jupiter, including the 4 major moons and some surface detail
Saturn, Rings and Major moons
Most of the 109 Messier Objects, some may require a dark sky
A large number of double stars, variable stars etc
Sunspots and the like ONLY VIEW THE SUN WITH A PROPER SOLAR FILTER, Such as Baadar solar film!

Some details on Jupiter and Saturn will be better with a higher magnification eyepiece such as a 8mm Plosssl, about another $25.

Back to Medium format

2007-04-04T13:39:00.000-07:00

I was photographing with the Rolleiflex today, and it felt good to have it back out. Its a joy to use, that big ground glass on top make composition so much nicer than on my 35mm SLR with its tiny view finder. It also felt like the film advance was working again. I will take in the roll of print film tomorrow to be developed. I love the waist level finder

At some time in the near future I will take it in to the shop for a CLA (clean, lube, adjust) it will probably cost a bit but the camera is so worth it. A joy to use, with wonderful optics and a big 120 format 6x6 film it just takes great pictures.

EDIT: The pictures of Belvior came back, they were quite good. I'm going to be using the rollei more often now that I know that it is working.

Some actual observing...

2007-03-31T11:37:00.000-07:00

Mostly the weather has been bad and I've been really busy, so I haven't had much time to observe.

However yesterday afternoon the moon was out in the afternoon sky, and could be seen in my home office window. I was able to get a nice view without ever leaving my chair care of my 15x70 binoculars. This morning as I got up before dawn to go to Natz* Jupiter was shining high in the south. Maybe one day this week I will get up to get a good look, as I didn't have a chance to get the binoculars out.

*Natz, is the jewish morning prayers done literally at dawn (IE The first possible moment you can) . I go because there won't be a long sermon to listen to.

Tools needed

2007-03-29T01:18:00.000-07:00

So I figure to build these scopes I will need these power tools:

Plunge Router (with some bits and jigs)
Miter saw. Specifically I will need to make an angle of 32° (as I live 32° north)
Hand drill
Jig saw

(Tools I have)

Non power tools that I may need:

Goggles (for eye protection)
Sandpaper
Clamps (a bunch)
hammer, screwdrivers etc
Tape Measure

All of this will also put me in a good position to build a bunch of bookshelves.

As for router bits, I think a Dado bit and something to let me cut circles, the dado may work there, a small quarter round might be helpful too.

I'm going to see if my jigsaw can cut on an angle with a jig. Cutting at 30° should be good enough. Or I can see if a neighbor has a miter saw that can do 32°

Two scopes

2007-03-27T12:00:00.000-07:00

So for right now I'm working on the 4.5" starter scope, after that I plan to make a larger (10-12") scope. The question is really how big a scope can I make that will still fit in the trunk of my car. It will be some time until I can afford the optics etc for this scope, so at this point its more a theoretical thing. For now I am planning on taking a tape measure to the trunk of the car.

Building an equitorial mount (Some Math)

2007-03-25T23:22:00.000-07:00

I want to build a simple equatorial mount, which is to say a mount that can be aimed at the North Celestial Pole, and then turn at the rate of 1 turn per sidereal day. Or 1 turn in 1436.06 minutes. This will match the rate at which the stars move across the sky.

To do this I will need a main gear which will be a wood disk cut on a router of radius R.
This will be driven by a threaded rod with 20 turns per inch turning at 1 rpm. This will move the disk at the rate of 1/2oth of an inch per minute. As such the circumference of the drive wheel must be (1436.06 minutes * 1/20 inches /minute) which is 71.8 inches.

Thus the radius (R) of the drive wheel should be 11.4278 Inches. I expect 11.45 or so will be about as close as I can machine the thing, this should be close enough for visual use and for astrophotoraphy as long as the exposures are short (say 10-15 minutes max).

In need of tools

2007-03-25T23:04:00.001-07:00

I found a few episodes of "The New Yankee Workshop", and have been watching them to learn something about woodworking. Last night I saw the router 101 episodes (as well as the lathe episode). It looks like plunge router and a few jigs will get me a long way to where I want to go.

To build various scope parts I will need a circle jig, which he showed how to make, and it looks quite doable.

Starting Small

2007-03-25T01:57:00.000-07:00

So I think I am going to start by building a 4.5" F8 small dob. The primary & Secondary will cost me about $53 (USD) with shipping plus any customs. I sent an email to the customs service to see how much that will be.

The next thing to decide is do I want to make it a solid sonotube or some sort of truss travel scope. I am looking around talpiot for sonotube, and will try to see how much it goes for. From there I can decide if I want to lug the scope around in 1 piece or not. I'm thinking with this one a solid tube makes sense.

Finding optics

2007-03-22T23:28:00.000-07:00

I have found these 3 companies that sell telescope mirrors on the low end.

Meridian has a 4.25" F8 mirror for about $32, which would be about $40 with shipping. This also includes a secondary mirror. It would make a decent long tube for a narrow field of view.

A 6" F5 mirror seems to be about $80. This would make a nice wide field scope. including a spider and mirror cell it would run me about $150.

If I want to go larger then I found a 12" F4.5 with secondary for about $399. It would need a mirror cell and a bunch of other stuff. This is a plan for the future.

I think for now the 6" rich field scope makes the most sense.

pocket microscope

2007-03-21T06:00:00.000-07:00

My dad sent me two 30x pocket microscopes. They are quite fun. I have one in the office today and have been showing it off to pretty much everyone. This thing is pretty simple. It has a small flashlight bulb to illuminate the target and a simple set of optics, which I assume are plastic. You don't need slides, just press the front end against what you want to look at and adjust the focus knob.

30x is enough to see quite a bit of detail without.

Things worth looking at (so far).

Coins
Bank notes
Fabric
leather (tooled leather even more so)
LCD screens.
A dish scrubby/sponge
A photo (not very useful, but interesting)

I have 2 of them, I'm going to at some point give one to each kid and give them a scavenger hunt where they have to find various types of features under the microscope.

This is pretty cool for a toy that costs about $9 (USD), plus 2 AA batteries.

rebuilding a telescope

2007-03-21T05:49:00.000-07:00

So I have this telescope. Its a meade short tube reflector. Which is to say that it has a spherical primary (bad) which is probably about F4 or F4.5. It also had a bad finder which is now broken and a crappy focuser and mount. So I'm going to rebuild it a piece at a time, until I have a scope that I like. First step is a new finder scope and a crayford focuser. The new finder is a 9x50 from Orion and the focuser is from the same source.

Next step is to rebuild the mount into something better for this there are 3 options:

A standard dob. maybe a travel dob. Basic alt/az platform scope, nothing fancy but will be easy to build.
A Equatorial mount. I have seen plans for some that use a wood disk for a drive wheel. My cousin in Hod Hasharon is a wood worker with a lathe so if he can help me this would be an option. This would require a motor that can be adjusted to allow it to track the sky. The major advantage here is that i could use this for piggyback photgraphy.
A Trackball. This would involve mounting the mirror in a sphere such that the scope could turn any way. It would therefore be possible to have a polar drive motor to track the sky, but it probably would not be possible to balance it to do photography.

If I go with 1 or 2 I may get a palm pilot or the like and hook up a mouse or two to act as an encoder to be a setting circle. This would allow me to know exactly where my scope is pointing and allow me to find object quite easily. On the other hand I'm not sure I want all that complexity, and of course there is the trunk space issue (my car is quite small)

Photoraphy and astronomy blog

2007-03-20T03:01:00.000-07:00

This blog is designed to be my photography and astronomy blog. Different from my livejournal. In terms of astronomy I'm mostly using a pair of Celestron Skymaster 15x70 binoculars. And trying to rebuild a meade short tube reflector into something decent over time.

In terms of photography I'm using a Pentax K-1000 (35mm), a Rolleiflex TLR 2.8E (120 format) and soon a Sinar F-1 view camera. I am almost exclusively shooting Film, mostly slide film (Fuji Provia and Velvia). I plan to start doing some black and white soon so I can develop at home.

Photography targets are mostly landscapes and the night sky.