robrj
Member
Posts: 248
home town/country: Escondido, CA
|
Post by robrj on Feb 16, 2017 23:55:45 GMT
That would be interesting. I've seen your videos on the mesh mask. I don't have a clear filter. I do have some screen mesh that I could cut up. Since it's just a proof-of-concept, I could probably make a small mesh and tape it on one of the carousel's open slots just to see if it gives a spike pattern. To use it for focusing with a narrowband filter, I'd need a clear filter that was parfocal.
|
|
|
Post by davy on Feb 16, 2017 23:56:30 GMT
Hi Howie What about making an actual bahtinov mask from sticker vinyl and sticking it to a filter lens,, I found a pattern years back on the web and cut one out in card with my vinyl cutter,. I'm wondering if I could make one small enough in viny.. another project lol
|
|
|
Post by davy on Feb 16, 2017 23:59:03 GMT
Hi rob I was thinking, would the moon glow filter be an option for it,, or would it dim a star too much
|
|
robrj
Member
Posts: 248
home town/country: Escondido, CA
|
Post by robrj on Feb 17, 2017 0:18:30 GMT
I don't have one of those either. Haha. When I was doing visual, all my filters were 2". I do have a 1.25" generic UHC filter but I think that would be too dark. I was thinking 1/2 of a polarizing filter might do the trick. The Zhumell 1.25" polarizing filter is $18 (US) but then decided to pick up an Optolong 1.25" clear ($24). I wanted one anyway. It's hard to plate solve with a narrowband filter (almost always fails).
If it was a lighter moon filter, that might work. You just need a bright star. My guess is if you can do it with Bahtinov mask, you should be able to do it with the screen over the filter. I wonder is a CLS filter would work? I have an extra one of those.
|
|
|
Post by davy on Feb 17, 2017 0:45:05 GMT
Yeah was the light grey I was thinking about... if I find the template for the mask on the net again I will see if it's feasible to do at 1.25 and 2" in vinyl,, would be pennies to knock them out if it works
|
|
robrj
Member
Posts: 248
home town/country: Escondido, CA
|
Post by robrj on Feb 17, 2017 0:50:15 GMT
That would be cool! Just stick and go!
|
|
|
Post by ChrisV on Feb 17, 2017 3:18:44 GMT
|
|
robrj
Member
Posts: 248
home town/country: Escondido, CA
|
Post by robrj on Feb 17, 2017 3:24:52 GMT
I don't know if you've seen the video or not but you have to cut the flyscreen in half and then put the bottom half together at a 45* angle to the top to get spikes.
Here's the video on making it:
|
|
|
Post by howie1 on Feb 17, 2017 3:25:59 GMT
That would be interesting. I've seen your videos on the mesh mask. I don't have a clear filter. I do have some screen mesh that I could cut up. Since it's just a proof-of-concept, I could probably make a small mesh and tape it on one of the carousel's open slots just to see if it gives a spike pattern. To use it for focusing with a narrowband filter, I'd need a clear filter that was parfocal. Yes Robert ... that would do (taping the two small semi-circles of mesh onto the carousel open slot) provided it doesnt foul anything internally to your filter wheel's innards
|
|
|
Post by ChrisV on Feb 17, 2017 3:46:29 GMT
|
|
|
Post by howie1 on Feb 17, 2017 3:55:23 GMT
Hi Howie What about making an actual bahtinov mask from sticker vinyl and sticking it to a filter lens,, I found a pattern years back on the web and cut one out in card with my vinyl cutter,. I'm wondering if I could make one small enough in viny.. another project lol I tried all ways of making bahtinov masks davy (too much time on my hands). Making small ones is reaaaaaaaaallly hard! That's why I use flyscreen mesh ones for my 50mm lens. - plastic or cardboard cutting fine holes to make the mask to the correct dimensions from various websites based on your scopes aperture. Waaaaay time consuming and tedious to do - taking the PDF file of the required mask as generated by the various websites down to Officeworks and having them print it out on clear film. So no cutting of all those numerous holes in the mask. Works but the film gets cloudy (excuse the pun give we are all astronomers here! LOL) and it ends up costing heaps continually getting it printed on clear laminate. - got a mate with a 3d printer to print one out. Works great but his printer could only go to about 6". Found a commercial guy but it cost way more than just buying a commercial one from an astro shop! It was only upon reading how a bahtinov mask actually works ... or how diffraction spikes actually happen ... that I finally realised flyscreen mesh would work. So simple to make ... so back in 2015 I made the video on my YouTube Channel. Flyscreen and carpet underlay ... works a treat.
|
|
|
Post by howie1 on Feb 17, 2017 3:59:06 GMT
I don't know if you've seen the video or not but you have to cut the flyscreen in half and then put the bottom half together at a 45* angle to the top to get spikes. Here's the video on making it: Hey Robert ... thats my Channel. I made that vid LOL Been using them for years. They are especially useful if you ever stick a Canon EOS lens onto a ZWO or other cam for widefield. You try and cut a very small mask the traditional way ... its really tough and they do not let enough light through. But very, very simple to make a small flyscreen one to fit a 50mm lens in a few minutes and they let heaps of light through!! Works a treat.
|
|
|
Post by davy on Feb 17, 2017 8:25:33 GMT
Brilliant guys,, seems a big push on, getting to know each other better,, keep the videos coming in,, it all helps someone out there.
|
|
|
Post by ChrisV on Feb 18, 2017 13:44:37 GMT
Lousy weather. Clouds and these hailstones So I made a little Howie flyscreen Bahtinov to fit over the 1.25" filter insert of a T-spacer. Then put different T-spacers between it and the ASI290 And it seems to work. Here's a series of shots of a fake star (torch shining onto a pinhole in a box) 1 to 4 - approaching focus. This was with the Bahtinov about 35mm away from the sensor. It doesn't look very Bahtinov-like out of focus, but the central star appears as a number of spots that converge and then look Bahtinov-like when in focus. Also, it seemed really sensitive. It seems to work better the further away from the sensor you go. Wouldn't work at all when it was less than 10-15mm away from sensor. Be good to try it on a real star ... And with a filter wheel, so then could check if it really is in focus. You're a genius Howie !
|
|
|
Post by howie1 on Feb 18, 2017 14:47:59 GMT
Thanks for the kind compliment Chris, but the real genius was Mr Bahtinov. Wonder how he figured out the mask in the first place?
Thanks for trying it out too Chris! I would never have had hands steady enough to do the fine cutting and such.
You can loose the central strip which divides the left and right hemicircles of mesh. Just leave it held onto the filter by the edges. That strip you have in the middle is so large relative to the light going through such a small thing as a 1-1/4" filter that it is causing that big dark line through your images. So take that centre white strip of tape off.
Next, I see the issue re why its 4 stars which have to be centered ... I've never seen that when using a big version for use at the end of a scope. Once again, I think it is a relative scale sort of thing ... IE if you think how tiny a star would be at the scale of that 1-1/4" diameter filter IE focused down somewhat since its light entered the scope at the aperture end. It is so tiny that the holes in the mesh are relatively large. Having said that ... it does seem to work when you get near focus. Any spike you look at will move left and right towards its neighbour as you move from out of focus, through focus, to out of focus again. You just tweak the focus knob until all spikes are equidistant to each other and bingo you have focus.
Cheers Howie (Aussie one!)
|
|
robrj
Member
Posts: 248
home town/country: Escondido, CA
|
Post by robrj on Feb 18, 2017 15:47:16 GMT
That's pretty cool. We've got a storm blowing through at the moment so it'll be a while before I can try it out. Focusing with filters can be tough (especially S-II). If I can get it parfocal with those, that would be awesome. Great idea Howie!
|
|
robrj
Member
Posts: 248
home town/country: Escondido, CA
|
Post by robrj on Feb 24, 2017 18:38:59 GMT
I'm going to give the focuser mask a shot tonight if the clouds permit. I was set to try it last night but the clouds rolled in. I cut two pieces of screen and taped them to the filter wheel with regular tape. It doesn't really stick to the screen but it holds well against the filter wheel so I don't anticipate any problems. I'll take some shots with the mask in place.
|
|
robrj
Member
Posts: 248
home town/country: Escondido, CA
|
Post by robrj on Feb 25, 2017 18:04:37 GMT
I gave the mask a shot last night. It worked well. Unfocused Focused
|
|
Deleted
Deleted Member
Posts: 0
|
Post by Deleted on Feb 28, 2017 20:13:24 GMT
Friends: I am making some progress with the Stick setup. Finally got it up and running after a bunch of error messages in Toaster. Had to reinstall. I also had some luck this weekend with a mask, not a screen one, but a commercially produced one, using Live View, and it worked great. I was at my obsy in dark skies, and at that point was simply shooting with EOS Utilities. This photo is no great shakes, but I sure was happy to get this much. ISO 1600, 120 seconds, tweaked a bit in Fotor. Can't wait to get the stacking up and running. About that, a question for Howie / "Carl": In your vid you seem to be pulling darks and other calibration files into the "stew" of the monitor folder. I note that DSS allows you to create darks files and such and store them. When using Astro Toaster, to employ darks is it necessary to lodge them in the monitor folder? If in another program you create a master calibration file, can you simply add that one file in the monitor? Or, does Astro Toaster / DSS work to find the calibration files in the native DSS folders. Thanks Jack
|
|
|
Post by ChrisV on Mar 1, 2017 0:21:50 GMT
Really nice shot for a single 120sec. Doesn't even look like you need darks and flats, really nice as is.
|
|