Click here if you are having trouble logging into the forums
Privacy Policy |
Please read our Terms
of Service | Signup and
Troubleshooting FAQ | Problems? PM a Red or a Green Gu.... uh, User
tim53
Pooh-Bah
Reged: 12/17/04
Posts: 1447
Loc: Highland Park, CA
|
|
fore
--------------------
"We`re just waiting looking skyward as the days come down.
Someone promised there`d be answers, if we stayed around."
-Orchestral Maneuvers in the Dark, "The Romance of the Telescope"
|
tim53
Pooh-Bah
Reged: 12/17/04
Posts: 1447
Loc: Highland Park, CA
|
|
Here's the setup I got the best image scale from:
William Optics 0.8x focal reducer/field flatener, 2x shorty barlow (really, just the barlow was too big, without- too small), Point Grey Research color Flea2 firewire camera.
-Tim
--------------------
"We`re just waiting looking skyward as the days come down.
Someone promised there`d be answers, if we stayed around."
-Orchestral Maneuvers in the Dark, "The Romance of the Telescope"
|
Mike I. Jones
Carpal Tunnel
Reged: 07/02/06
Posts: 1572
Loc: Fort Worth TX
|
|
Tim,
Which FLEA2 camera did you get? Point Grey has them in 7.4um, 4.65um and 3.75um pixel sizes. We have some at work and I've been wanting to take one home and try it on my scopes. At your focal ratio of f/15 the 7.4um array is probably best matched to the optics, and has the highest sensitivity of the three. Either the 7.4um or 4.65um cameras would work well with my 16" f/6 Newt.
Mike
--------------------
56 mirrors, lenses, 16" f/6 Newt, 6" f/10 refractor, TOA-130S, Tinsley 5" f/15 Mak, 6" f/4 RFT, Coronado PST. Still to build: 24" f/10 Modified Dall-Kirkham, 10" f/26 Mak, 8" f/12 apo, spectrohelioscope, Herrig, Schupmann, and others.
|
mikey cee
Post Laureate
Reged: 01/18/07
Posts: 3520
Loc: bellevue ne.
|
|
Tim....I'm lost here. Is that scope that lens heavy or is it more convenient to get the eyepiece locale closer to your work? Also did you knock off your chimney and then cap it? Nice looking home there.  Mike
--------------------
7x35 and 10x50 sears tower binocs, 3" f/10 edmunds reflector, 2.4" f/11.7 manon refractor, 6" f/8 jaegers refractor, "The 8 Ball" 8" f/13.3 brandt refractor, 3" f/15.8 sans&streiffe refractor, 3.1" f/15 selsi refractor(towa 339), 2.4" f/15 sears refractor, selsi 30x30mm spyglass, criterion 5-draw 25x45x75x spyglass(1957), 4.25" f/14.8 tasco 20te.
|
tim53
Pooh-Bah
Reged: 12/17/04
Posts: 1447
Loc: Highland Park, CA
|
|
Quote:
Tim,
Which FLEA2 camera did you get? Point Grey has them in 7.4um, 4.65um and 3.75um pixel sizes. We have some at work and I've been wanting to take one home and try it on my scopes. At your focal ratio of f/15 the 7.4um array is probably best matched to the optics, and has the highest sensitivity of the three. Either the 7.4um or 4.65um cameras would work well with my 16" f/6 Newt.
Mike
Mike:
This one's the Flea2 with 1032x776 4.65 micron pixels. I tend to use this one more than my Flea 640x480 with the 7.4 micron pixels because it's easier to pick a ROI and get a larger range of possible image scales. I've compared them, and when they're at the same scale on planets (requiring different barlows on same scope), the sensitivity is the same.
Also, with Astro IIDC, you can bin COLOR, though you have to change the R and B gains to balance things. I've been wanting one of the bigger chip Pt Grey cameras. Unfortunately, the one I'd want is the Grasshopper with the Exview HAD chip in it (same as the DSI III Pro), and it's something like 2600 bucks!
Here's one of my Jupiters from this morning. I'm still processing, so this might not be the best. In addition to the optical train above, I had a Baader contrast booster in the system. Without it, there's still too much CA for planetary color imaging. But at least I can get good color balance with it on the f/15, whereas I can't with the f/10.
-Tim.
--------------------
"We`re just waiting looking skyward as the days come down.
Someone promised there`d be answers, if we stayed around."
-Orchestral Maneuvers in the Dark, "The Romance of the Telescope"
|
tim53
Pooh-Bah
Reged: 12/17/04
Posts: 1447
Loc: Highland Park, CA
|
|
Quote:
Tim....I'm lost here. Is that scope that lens heavy or is it more convenient to get the eyepiece locale closer to your work? Also did you knock off your chimney and then cap it? Nice looking home there. Mike
Mike: Yep, it's heavy at the lens end. The wood components are actually quite light. Probably a lot lighter than an aluminum tube would have been.
That chimney has been cut off for as long as any of the neighbors can remember. I'm guessing the Long Beach earthquake of 1933, but I have no particular reason for picking that date. The other two were cut off after the Sylmar quake.
When we were rebuilding our house after the roofer set it on fire in 2001, we looked into having the chimneys rebuilt to match pics (of the other two, this one there are no pics of that we've found... ...yet). We were quoted upwards of $100K, so it's not going to happen soon!
-Tim. 
--------------------
"We`re just waiting looking skyward as the days come down.
Someone promised there`d be answers, if we stayed around."
-Orchestral Maneuvers in the Dark, "The Romance of the Telescope"
|
tim53
Pooh-Bah
Reged: 12/17/04
Posts: 1447
Loc: Highland Park, CA
|
|
Here's one with just the 2x shorty barlow in place, resized to 800x602 pixels
--------------------
"We`re just waiting looking skyward as the days come down.
Someone promised there`d be answers, if we stayed around."
-Orchestral Maneuvers in the Dark, "The Romance of the Telescope"
|
Mike I. Jones
Carpal Tunnel
Reged: 07/02/06
Posts: 1572
Loc: Fort Worth TX
|
|
Looks great! Try making a composite shot through a few different narrow-band filters rather than a white-light shot. Focus at each different wavelength with a Bahtinov mask. That's a sharp lens at any one wavelength or correct pair of wavelengths between F and C, just not all of them together. Blue and violet focus farther away from the lens, so the image scale actually increases slightly and has to be compensated for when making the composite image.
Love the King Crimson avatar. I wore the grooves off that LP back in the 70's. You know that Fripp tours with the California Guitar Trio now, right?
Mike
|
tim53
Pooh-Bah
Reged: 12/17/04
Posts: 1447
Loc: Highland Park, CA
|
|
Quote:
Quote:
Well, it's pretty obvious!
I still couldn't figure out where to put it when I was done, so it's on the dining room table!
-Tim.
Just take it...and be the better for it..
She'll probably fall in love with it too...it's awesome!
Rob
Well, I was struggling with where to put the scope when I take it down, and my wife made the suggestion that I set it up in the living room on the NJP!
This way, I can cogitate on how to rig up tube weights after I get home from work!
-Tim.
--------------------
"We`re just waiting looking skyward as the days come down.
Someone promised there`d be answers, if we stayed around."
-Orchestral Maneuvers in the Dark, "The Romance of the Telescope"
Edited by tim53 (07/12/09 08:28 PM)
|
tim53
Pooh-Bah
Reged: 12/17/04
Posts: 1447
Loc: Highland Park, CA
|
|
Quote:
Looks great! Try making a composite shot through a few different narrow-band filters rather than a white-light shot. Focus at each different wavelength with a Bahtinov mask. That's a sharp lens at any one wavelength or correct pair of wavelengths between F and C, just not all of them together. Blue and violet focus farther away from the lens, so the image scale actually increases slightly and has to be compensated for when making the composite image.
Hi Mike:
Well, I got up this morning about 5am (starting to get light) and plugged the scope in and attached my Meade DSI Pro III with filter bar to the scope for some filtered imaging tests (via Nebulosity on the mac) like you suggested, changing focus for each color. I was still rather groggy, though, and the coffe wasn't ready until I was well into the imaging sequence, so I forgot to put the IR block filter back on the nosepiece. So IR was getting into the RGB filtered images. I did notice a wider range of "good" (but not great) focus with the green and blue filters (duh!), but I'd have to repeat the experiment in a lot more awake condition for the results to be meaningful.
...and unfortunately I took the scope down to set up again in our living room, because it looks like it'll be about a month before I can spend much time again on the project.
Until then, I'll likely do any imaging I get time for either with the NP101is, my good ol' Orange tube C-8, or the Nexstar 9.25 GPS.
Quote:
Love the King Crimson avatar. I wore the grooves off that LP back in the 70's. You know that Fripp tours with the California Guitar Trio now, right?
Mike
Yep. I'm a big fan of Fripp, but especially the early King Crimson stuff. The later stuff isn't quite as cool.
-Tim.
--------------------
"We`re just waiting looking skyward as the days come down.
Someone promised there`d be answers, if we stayed around."
-Orchestral Maneuvers in the Dark, "The Romance of the Telescope"
|
tim53
Pooh-Bah
Reged: 12/17/04
Posts: 1447
Loc: Highland Park, CA
|
|
I should ad that I've tried this with the 6" f/10 before (though not with a monochrome camera and filters, but with Bayer on-chip RGB filtered color cameras), where I shot video sequences in red, green, then blue monochrome mode, refocusing for each. At that f/ratio, I found the blue channel to be way too soft, even at "best" focus. To be fair, though, I should try that again with the DSI (and the IR blocker!), because the red and blue pixels are only a 1/4 of the total number in a bayer color camera.
-Tim.
--------------------
"We`re just waiting looking skyward as the days come down.
Someone promised there`d be answers, if we stayed around."
-Orchestral Maneuvers in the Dark, "The Romance of the Telescope"
|
tim53
Pooh-Bah
Reged: 12/17/04
Posts: 1447
Loc: Highland Park, CA
|
|
I reprocessed that Jupiter picture I posted above. I think this is more better:
--------------------
"We`re just waiting looking skyward as the days come down.
Someone promised there`d be answers, if we stayed around."
-Orchestral Maneuvers in the Dark, "The Romance of the Telescope"
|
Jim Curry
sage
Reged: 10/29/07
Posts: 432
Loc: Maine
|
|
Tim:
I've been silently following this thread. Fantastic workmanship. This last photo of Jupiter is great, too. As far as tube weights go you might consider some weights extended from the saddle to keep from overloading the tube. Weights at the end of long rods, I'm sure you've seen them on some classic scopes.
Jim
--------------------
Vixen 140 refractor
|
tim53
Pooh-Bah
Reged: 12/17/04
Posts: 1447
Loc: Highland Park, CA
|
|
Hi Jim:
That's an interesting thought... sort of "Zeiss-like", though they also mounted the Griffith 12" on an inverted fork mount.
For my 6" f/10, I simply attached short dowels big enough to fit inside standard barbell weights to the tube, then put on the weights, followed by fender washers and screws into the dowels. But those weights are only 2.5 pounds apiece. I'll likely need a pair of 5 pounders for the f/15!
-Tim.
--------------------
"We`re just waiting looking skyward as the days come down.
Someone promised there`d be answers, if we stayed around."
-Orchestral Maneuvers in the Dark, "The Romance of the Telescope"
|
|
10 registered and 2 anonymous users are browsing this forum.
Moderator: Don W, Mike I. Jones
Print Thread
|
Forum Permissions
You cannot start new topics
You cannot reply to topics
HTML is disabled
UBBCode is enabled
|
Thread views: 1381
|
|
|
|
|
|
|
Previous
Index
Next
Threaded
[Re: 
Edit
Reply
Quote
