Practise for the Total Lunar Eclipse!

[iceman (Mike)]

Don't forget everyone, just over 4 weeks until the Total Lunar Eclipse on the 28th August 2007.

It's Full Moon tonight/tomorrow night, so take this opportunity to practise the techniques you'll be using on Eclipse night. Try different settings on your camera, different telescopes or focal length lenses, different post-processing techniques, etc.

Don't forget to read the article here, Total Lunar Eclipse, 28th August 2007 and the thread discussing it is here.

Good luck and post your trial full moon shots in the Solar System forum. If you'd like some advice on improving your shots, please just ask and we'll be glad to help!

[OneOfOne (Trevor)]

Originally Posted by iceman

It's Full Moon tonight/tomorrow night, so take this opportunity to practise the techniques you'll be using on Eclipse night.

I am not quite up to taking shots with my new scope yet, but the one thing I will be doing is checking where the Moon rises so I know where to set up and not have a tree in the way! Also thinking of inviting some friends/neighbours over for a look and it would be just too embarasing if I had the scope in the wrong place

[Lee]

Gee - may half my obs mostly built by then.... will be able to watch it from my bare ply floor I'd say, could lean back on the pier and enjoy!

[Astroman (Andrew Wall)]

I'll be out practicing as soon as I can see the clear sky.

[KG8]

I had a bit of a go tonight with my little canon powershot 560 Mike. Don't know if I can stick it up the tailpipe of the C11 but I managed to take a series of shots through a 20mm EP on a little Celestron 90mm mak I have here. The moon almost filled the EP so I got a good look, the camera seemed to focus alright too, which surprized me. The first shot below was taken through the camera at 4*zoom and no scope. Cute I thought, though no detail and I had to hold a bic lighter in front of the lens to get the shutter speed up. That was a mission, took 20 goes until I lucked a 1/250 speed and got a lifelike pic. The Big photo was 1/500 I think? Cut down in size by 3/4 to get on IIS


Frank.

[sheeny (Al)]

I got some clear sky tonight, so out I go...

I very quickly got the Oly C5060 sorted to capture widefield images to show the path of the moon and colour changes: 80ASA, f/8, 1/100sec, FL=6mm.

Had a bit more of a play with the E-510, but the 40-150mm lens just isn't long enough, for good results.

So time to experiment. I worked out the moon should give reasonable image scale in the ToUcam at about 200mm focal length. I also know the ToUcam works well imaging the moon at f/25 though my C8, so I figure I'll try my OM Zuiko 100mm lens with a Tamron 2x teleconverter, with the lens set on f/11 that should give me 200mm @ f/22 should be pretty close!

Noooooo... too bright! Can't get the exposure down enough in K3, and adjusting the lens aperture seems to have no effect... OK, so I put a pair of crossed polarizing filters on the front of the lens... no, still to bright. ...but I did notice that while fiddling with the crossed polarising filters I occasionally got good images/contrast while my hands nearly fully covered the front of the lens... hmmm

So I got the lid off a can of spray paint and drilled a 5/16" hole in it and stuck that over the front of the lens... still no joy... What??? the hole's too big??? A bit of masking tape over it and I put a 3/32" hole in the masking tape. OK, now the contrast is good but the resolution is poor.

OK, then... off with the masking tape, and I got my 18%ND Moon filter and put it into the filter holder for my ToUcam to T-thread adapter and slipped than into the Mogg adapter behind the lens...

Viola!

I'm not sure why the aperture on the lens didn't seem to have an effect - it works fine on either the OM-1 or the E-510, but changing it from f/2 to f/22 didn't seem to have any effect on the TouCam (though I haven't played with it since I got the agricultural grade aperture sorted...

Anyway, I thought a low tech solution might be appreciated by some bods here!

Al.

[iceman (Mike)]

Fantastic results, guys.

Frank - your second shot is very good. With better framing and some post-processing, it will be just what you need on eclipse night. I've attached a post-processed version of your shot as an example. Obviously I couldn't do anything about the framing Cropped, sharpened, levels and curves adjusted. Oh also converted to greyscale.

Al, those are great! Well done on the techniques! The only problem with the ToUcam will be the lack of resolution (640x480), but it's a good size to make an animation!

[sheeny (Al)]

Originally Posted by iceman

Al, those are great! Well done on the techniques! The only problem with the ToUcam will be the lack of resolution (640x480), but it's a good size to make an animation!

The plan for the ToUcam is an animation and a montage . I'm toying with the idea of a ring of smaller holes in the spray can lid aperture mask to allow the same amount of light but to increase resolution...

Unfortunately, I just don't have a camera/scope/lens combination that would allow good hi resolution shots of the eclipse, so I'm relying on the rest of you guys!

Al.

[sheeny (Al)]

Originally Posted by sheeny

The plan for the ToUcam is an animation and a montage . I'm toying with the idea of a ring of smaller holes in the spray can lid aperture mask to allow the same amount of light but to increase resolution...

Al.

OK I've done the calcs...

I had a 5/16" hole in the improvised aperture mask. Dawes limit for that set up is 14.5 arc seconds. The pixel resolution of the ToUcam is 5.77 arc seconds, so the images I captured at practice the other night aren't as sharp as they could be ( I thought that was the case! ).

Now I can get the same amount of light by drilling 4 x 5/32" holes in the aperture mask, and I can increase the resolution by spacing them apart. To decrease the Dawes Limit to less than the pixel resolution, I need the holes at least 20mm spacing. So I'm goignt o have to produce an aperture mask with 4 x 5/32" holes at say 23mm pitch circle diameter... that should bring Dawes Limit down to 4.64 arc seconds < 5.77 arc seconds.

Now to find myself another aerosol lid... (If worst comes to worst I can use the same one and tape up the first hole... and make sure I have the tape with me in case it's a last minute revert to plan A! )

Al.

[KG8]

Originally Posted by iceman

attached a post-processed version of your shot as an example. Obviously I couldn't do anything about the framing Cropped, sharpened, levels and curves adjusted. Oh also converted to greyscale.

Well that's a definate improvement on my basic pic, thanks for taking the time out iceman. Not being into astrophotography in any way aside from some snaps off the tripod I am illiterate when it comes to post processing platforms or techniques. All I know is that it looked a lot better in the EP than on my pic when I put it up. I will experiment a bit more, perhaps selecting the B&W mode or the *MyColours* mode.

[Omaroo (Chris Malikoff)]

I'm a few days late here, but I've been experimenting tonight with the C8,the Megrez 80mm and the Saxon 120mm refractors. The camera is a Nikon D40. The C8 is out of the picture because at 2,000mm FL I can't get the whole object into the camera's FOV.

Pic 1) Second one taken through Saxon 120mm f/8 refractor and a natural frame size.

Pic 2) Here's one through the Megrez and taken with the Nikon D40 at 200 ISO @80/sec.

Pic 3) Again through the Megrez but with a 2x Barlow.

Given this, I think that I'll be using the Megrez & Barlow on the night as it seems to take the most appropriate object size in relation to the FOV and is a good deal smaller to lug around than the Saxon or C8.

Cheers
Chris

[iceman (Mike)]

They look nice Chris, you've got just the focal length you need.