Svbony 305

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signman
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Svbony 305

Post by signman »

Hi All

Total newbie to astro photography so please bear with me, hence my purchase of a fairly low entry model in the shape of a Svbony 305 which I hope to use for planetary and moon.Scope is a Skywatcher Mak 127 on an EQ3-2 with RA motorised drive.
Having set up ok and everything looking good with Sharpcap, I read somewhere it would be good to do some terrestrial viewing to get familiar with the software.So, where I live its surrounded by trees in leaf and the most distant is only around 400m away. I focused on these trees with a 32mm plossl to get the range and dropped in the camera which gave me a very fuzzy and highly magnified image on my PC. Try as I might I cannot get a sharper image in view using the scopes focus nor the software, I tried lengthening the distance of the camera firstly from the star diagonal with a barlow with its lens removed then from the back of the scope nor to no avail having the camera directly into the back of the scope. Sharpcap seems to be working ok as I can get changes on the PC from the various functions.
So am I focussing on a subject that is too close and moving around in the wind, would I be better off waiting for a nighttime session? Am I missing something fundamental or is the camera a dud?
Thanks.
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admin
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Re: Svbony 305

Post by admin »

Hi,

I think your camera is probably okay and you are just having trouble getting it at the right distance to get good focus. If you are looking at relatively nearby objects then the camera needs to be further back from the telescope then it does when you are focusing on distant things like the stars. You will usually want the sensor of the camera to be somewhere (roughly) in the region of the shiny barrel part of an eyepiece that is in focus.

Getting the camera in roughly the right position so that you can start homing in on a good focus is one of the most frustrating parts of beginning astrophotography – to stick with it though as you will find the right position in the end.

Cheers, Robin
signman
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Re: Svbony 305

Post by signman »

Hi Robin

After a fruitless night trying to focus on Spica I opted for a daytime session on some hills about 1.5/2 miles distant and had some slight success in viewing a house and the trees behind, images where blurry and the heat rising from the ground wasn't helping a bit.
Today I set up a football on top of a chimnea pot some 25m away and managed to get a good image albeit zoomed in to one of the hexagons, which proved the camera is working however I can't seem to zoom out or zoom in further, I seem to have a fixed point and I cant find a function in Sharpcap software to control this.

Any ideas ?

Thanks

Steve
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admin
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Re: Svbony 305

Post by admin »

Hi Steve,

Yes, there is no way for these cameras to have the zoom function in software. The closest to that is selecting a capture area that is smaller than the overall sensor size so that you capture for instance an area of 640 x 480 pixels instead of the full sensor area of 1280 x 960 pixels. To be honest although there are some use cases for doing that, it's not desperately helpful.


The way to get a narrower or wider field-of-view is to use a telescope with a longer or shorter focal length – longer focal lengths will give you a narrower field-of-view (more zoomed in) and shorter focal lengths will give your wider field of view. Since additional telescopes tend to be expensive (!), you can use things like a Barlow lens (to increase the focal length of your existing telescope) or a focal reducer (to reduce it).

Cheers, Robin
signman
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Re: Svbony 305

Post by signman »

Hi Robin

Thanks for that, I think a focal reducer would probably be the less expensive option. Although looking through some of these websites only just!!!
Will try again when the moons up.

Thanks

Steve
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turfpit
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Re: Svbony 305

Post by turfpit »

Steve

Cost is around £25 and should screw into the nosepiece of the camera (check with vendor).
https://www.365astronomy.com/365Astrono ... onomy.html

Dave
signman
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Re: Svbony 305

Post by signman »

Thanks Dave, I've gone ahead and bought a Svbony 0.5 from China, should be arriving in a few days time.My thoughts are it's so cheap as to be a throwaway item, if it's half good then it's a bargain, and I can then think of getting something better.
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turfpit
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Re: Svbony 305

Post by turfpit »

Good move Steve. It is easy to spend money on gear but that does not mean instant success. There is still a learning curve to get the best out of anything purchased.

Dave
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