Mars, bad seeing and image scale - 9th Oct

iceman (Mike) · #1 10-10-2005, 09:07 AM

Hi guys.

I was out imaging Sunday morning at 1am, even though it had been blowing a gale all day in the Sydney area, I thought I'd try my luck.

Alas, it wasn't any better at that time of morning. The wind was still blowing hard and the seeing was terrible, 3/10 at best. I was dying to try my new 5x powermate though, so I did some experiments to pass the time.

Attached is a composite image showing Mars at different image scales, by using different barlows. You can see how, when the seeing is bad, the image deteriorates the more you push the magnification.

I know the images are not good, but I thought the results might be of interest to some.

vindictive666 (John) · #2 10-10-2005, 09:15 AM

still looks ok to me mike

davidpretorius · #3 10-10-2005, 09:38 AM

New favourite thread to be added to the iis awards.

This is great for educational purposes Mike. Thanks!

I also have a new background for the computer.

ving (David) · #4 10-10-2005, 09:41 AM

the 3x looks about the limit. good stuff mike

atalas · #5 10-10-2005, 09:57 AM

Yeah what David said, but boy the 5 x powermate when the seeing permits will be a gooden ! Sunday sure was windy in Sydney alright ,my auto-guider was doing donuts

Louie

Eardrum73 · #6 10-10-2005, 09:59 AM

hey this stuff is great....

Especially for newbies like me. Now I roughly know what type of barlow to get... sounds like 2.5x or 3x is good for my 12' dob.

cventer · #7 10-10-2005, 10:35 AM

Nice post mike. Its cool to see the various image scales. I have been trying to decide what barlow to get myself. I want a 2" powermate so just need to decide what image scale is best suited to my C925

Regards
Chris

iceman (Mike) · #8 10-10-2005, 10:40 AM

Thanks guys. I just wish the seeing was better so I had some better final images.

Chris, what's the FL of the 925? I'd imagine the 2x 2" would be about the limit most times wouldn't it? Although if the seeing is really good, you'd want the 4x as well

Just get both

ving (David) · #9 10-10-2005, 12:34 PM

Quote:

Originally Posted by Eardrum73

hey this stuff is great....

Especially for newbies like me. Now I roughly know what type of barlow to get... sounds like 2.5x or 3x is good for my 12' dob.

only if your are imaging like mike. 3x is prabbably still too much for visual. believe me, 2x is plenty for you

iceman (Mike) · #10 10-10-2005, 12:41 PM

Agree with Ving - a 2x barlow, or 2.5x powermate, is all you need for visual. It'll give you the most use out of your eyepiece collection.

ving (David) · #11 10-10-2005, 12:47 PM

of course you agree with me... I am always right!

asimov (John) · #12 11-10-2005, 02:29 AM

Very good Mike. Nothing like a visual demonstration to really drive a point home. I've been trying out other stuff as well like unscrewing the actual barlow lens element section & attaching directly to the EP. Certainly opens up the magnification range even more so depending on how many EPs one has & what FL they are.

Good job mate.