Cloudy NIGHTs
UmaDog : 02/26/11 12:04 AM from Long Island, NY
Thank you for sharing your images of Saturn. How about M93 next?
MANDII : 02/26/11 11:41 AM
Thank you .
Yes, I may try this one , the M93 cluster .
Because as I check it just now , it's in location about 40 degree elevation in southern side at time around 9:00 p.m in this season , that is a good timming and good position for me , because normally I can afford to do imaging from 9:00p.m to 12:00p.m , too late I need to go bed . And 40 degree is a good position . I mean easy to manupulate the scope . But just one thing that the southern sky area may get a bit light pollution in my area .
let's see it .
Need to wait good weather comes ,and bring me some clear nights .
mexjon : 02/25/11 09:59 AM from Jacksonville, FL- Merida Yucat...
Is it just not barlowing well, or is it a matter of fine focus? Your very first one with 2X is so much clearer than even this one, although this one is so much better than the other 3X. I'm sure you're going to figure this out soon.
I think maybe you should play with the frame rate a bit and see what difference that makes.
MANDII : 02/25/11 10:48 PM
Yes , John .
Actually , the reason can be much . ..
At first , if the maginification getting higher , the image should be less sharp , this is very natural . My scope is 6" aparture 750mm FL , maximun magnification should be around 150mm X 2 = 300X . I had used a 7mm eyepeice to look at the saturn that night , 7mm plus the 3X barlow equal (750mm/150mm X3 )=321 , means magnification 321 is larger than maximun allowance . So when I look at it in eyepiece , it's already getting blur , but not very blur . However , The picture captured and after processed , is better than visual observation . But I am not sure what magnification is when I am using the DSI camera . I think the FL of a DSI is very similar to an 7mm eyepiece , I mean the Focal length , but anyway , I am not sure at this point .
2ndly , the 3X barlow is good or not , I cannot know it . I got it at ordinary price . I only know the second 3X picture is better than the first one .
3rdly , the sky condition is also varies , but this should not make it differnt so much , because the two nights seems not so big difference in transparancy .
Fouthly , image process is also needed to be counted .
This time I use IRIS , not Registax .
Finally as you said , exposure timming / capturing timming can also cause the difference .
So... I cannot find out what problem is , or even if there is any problem or not , for this 3X saturn .
mexjon : 02/27/11 08:19 AM from Jacksonville, FL- Merida Yucat...
I think it would go like this MANDII. 7mm x 3x barlow would make it a 2.3mm eyepiece equivalent. 750mm/2.3mm = 326X, a little over your maximum, and a bit more than the way you figured it.
It would take some transparency to be clear at that high mag. Maybe cut down to a 2.5x barlow, and make sure it's quite high in the air. I think.
Are you sure that you are getting a good focus, or do you need to extend/shorten the train a bit to get optimum focus? I would start a new thread in the Astrophotography forum where someone who knows could help you. I will enjoy following that thread. This is, after all, observatories.
MANDII : 02/27/11 08:23 PM
Thanks for your opinion , John .
台湾
aa : 2011-02-25 16:26
6" 鏡的倍率一般在 150左右
如果大於 150倍，就會糊掉了...
MANDII : 2011-03-01 09:02
恩,我想是了。应该没有理论(理想)的150mmX2 =300倍那么高了。 |
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