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Old 07-10-2020, 09:37 AM
evltoy (Wayne)
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Why is my Image via my camera not sharp?

Hi everyone,

First off… this is my first post on this site, so please forgive me if I have posted my question in the wrong area.

I have myself a Celestron Evo 8” (non-HD) that is fairly new. I too am very new to this game with only being involved since Dec 2019…. I have a lot to learn.

My issue is I’m not sure why I would be getting very soft to almost blurry images when using my SvBony sv205 webcam. When doing visuals through my eye pieces (40mm. 13mm & 6mm with diagonal) the Moon, Saturn and Jupiter look very sharp.

I have connected my sv205 webcam in different combinations, but the results are somewhat the same. I have to add I’m not running out of focus when using the webcam. Here is how I have connected it.

1- SCT->visual back->diagonal->sv205
2- SCT->visual back->sv205
3- SCT->visual back->diagonal->2x Barlow->sv205
4- SCT->visual back->2x Barlow->sv205


Before posting here I had spent a lot of time researching about my issue and setup (obviously not enough as I haven’t found a solution as yet). I have looked into collimation and I have collimated my OTA to the best of my ability by using a bright star out of focus. The next thing that came up on my search was back focus. With the setups I did above, do I require spacers to increase my back focus, to what length and how? Or could it just be that my “seeing” conditions were not optimal?

Doesn’t anyone here have or has used the 2 items I’m using and how did you connect them to get a sharp image?


On a side note… I do have a Nikon D80 DSLR that I used and got the same result. At the time I did not have the #93633-A T-Adapter, so I had used the 2x Barlow that has a T-Adapter and attached it to either the diagonal or directly to the visual back. I now have the #93633-A T-Adapter, but have not had the opportunity to test with it.


Thank you in advance for your feedback and help.

Cheers
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Old 07-10-2020, 10:01 AM
sunslayr (David)
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You are probably running into atmospheric distortion. The planets will look a little blurry in your camera due to atmospheric turbulence. Unlike your eye, your camera can't blend multiple frames to build a clearer image. For planets we use a technique called 'lucky imaging'. First you record a video of the planet at a high frame rate, then software can pick the best frames and then average them together. Finally we use wavelet sharpening to bring even more details back.
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Old 07-10-2020, 10:11 AM
evltoy (Wayne)
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Thank you sunslayr for your feedback. I too did think of this, but wanted validation from more experience people.

I do use video and its highest frame rate it can do before frames are dropping via Sharpcap. I then stack the video in AutoStakker!3 and once done use RegiStax6

As I am very new to these software and not 100% sure if I altering the right parameters to give me the best image

I'll see if I can post my image
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Old 07-10-2020, 10:37 AM
evltoy (Wayne)
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Here are some photos I ended up with after processing (Mars, Jupiter & Saturn) on 1 Oct 2020. This is my first attempt at stacking I have done so far.

Please be kind
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Old 07-10-2020, 11:51 AM
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multiweb (Marc)
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Why is my Image via my camera not sharp?
Story of my life.
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Old 07-10-2020, 03:04 PM
sunslayr (David)
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It could be a number of things affecting your image, I'm afraid I'm not experienced enough to tell you exactly what it is from your images. To maximise your chances of capturing a good shot of a planet you'll want to do a number of things:

Record when the seeing is good, usually later when the air is cooler
Avoid shooting over buildings or through windows
Capture it when it is fairly high in the sky
Make sure as little glass is in the way, so no diagonal
Make sure the telescope has cooled down
Focus precisely, a batinov mask can help with this
Record with a high frame rate, using a smaller ROI and high gain will help with this
Make sure you don't record for too long, planets rotate this can add motion blur to the image, depending on the target 1-2 mins is probably a good max.
Watch some videos and/or read tutorials on autostakkert and registax, the amount and levels of sharpening can mean the difference between ok and fantastic images.

And finally practise, with experience you will be able to watch the camera feed and know wether Jupiter is jumping around too much to record or if you have brought all you can out of your image. Of course you might not be able to get everything but do what you can. The challenges are what makes the reward all the sweeter.

Last edited by sunslayr; 07-10-2020 at 03:17 PM.
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Old 07-10-2020, 04:48 PM
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mswhin63 (Malcolm)
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Hi Wayne, I am now expert but usually the first thing I do I look for others that have taken images with he camera. Even the SV105 which is an inferior camera. The SV 305 it higher grade therefore images like this - https://www.svbony.com/blog/30mins-s...ure-time-1800s are not comparative.

Upon looking I see a number of reasonable images from SV105 (Google search) there are a few of reasonable quality - https://www.cloudynights.com/topic/6...105/?p=9572396

So it is possible to get good images with that camera.

Looking at your current images there is a significant fringing of Blue/Green around the planets especially noticeable on Mars. Personally I would test the imaging assembly, Scope, Barlow and so on.

See if it is possible to take a day time image pointing the scope to some object and test the clarity. Through a scope the images may appear contrast lacking but the clarity should be there.

I have used webcams to image jupiter and they have always started out rubbish, but after playing around a bit the images improve. Before finishing planetary imaging temporarily about 7 years ago I managed some reasonable one with my Dob on an EQ Platform. So maybe a little more time and fiddling around you can get there.
The one linked here is one I took with my current webcam now used as a guide cam and is low res than SV105 - https://photos.app.goo.gl/AChHL7uPnDqKkhu38

Keep at it!

My 2 Bobs worth.
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Old 07-10-2020, 05:10 PM
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Hi Wayne,

It's a tough journey planetary imaging. Don't be too disappointed. If these were your first attempts, it's a great start.

There are a couple of things working against what you are wanting from your planetary imaging.

First you are using a camera that looks like can only go to 30 FPS (correct??) and is a lower cost colour unit. A better choice would be to update this so you get higher FPS rates with one of the latest CMOS cameras such as those by ZWO. As an example, I am capturing at 100 FPS at the moment with a Mono camera called ASI 290MM.

Mars - it's a tough object! In your image, you can see that either planet is out of focus, or at low elevation, or in very poor seeing as one side has a red edge and the other side has a blue edge. Wait until Mars is at 40 degrees, and only image when the seeing is good. Also make sure you allow your scope ample of time to cool and reach ambient - leave it outside, blow cold air on to it, get a SCT cooler that you can insert into the focuser.

Also keep in mind that you only have a 8". Most of the images that people are posting on the net which look amazing are with larger telescopes and also taken with Mono cameras that have better resolution under excellent seeing conditions.

The journey towards capturing great planetary images is a long one! It's not just a case of plugging the camera into the scope and expecting amazing images (sorry!).

Once you have got capturing down pat, then there is the processing side of things - it's not just a case of stacking - sharpening is a whole art in it self including achieving colour balance and good levels of contrast.

If it makes you feel better, my first image of Saturn using a low cost colour webcam is here: https://www.flickr.com/photos/johnka...album-1162379/

Then 11 years later: https://www.flickr.com/photos/johnka...album-1162379/

- Both taken with the same scope from the same location -

Keep asking questions, sharing your results, and learning new techniques! After 15 years of planetary imaging I sure still am!

Clear skies.

John K.

Last edited by John K; 07-10-2020 at 05:30 PM.
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Old 07-10-2020, 07:56 PM
evltoy (Wayne)
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WOW! I should have asked my questions here a long time ago.

Thank you to all for your advice and information you have provided me. This is very valuable to get me started on the right track.

I will for the interim use my cheap webcam and try to suck out as much as I can from it, but down the track I am looking at ZWO ASI290MC.

Since the weather has been crappy I will play around with my footage and see what parameters I need to play with to get a better image... who knows, maybe there is something hidden that I didnt bring out.

Cheers
Wayne
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Old 08-10-2020, 10:22 AM
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Originally Posted by evltoy View Post
WOW! I should have asked my questions here a long time ago.

Thank you to all for your advice and information you have provided me. This is very valuable to get me started on the right track.

I will for the interim use my cheap webcam and try to suck out as much as I can from it, but down the track I am looking at ZWO ASI290MC.

Since the weather has been crappy I will play around with my footage and see what parameters I need to play with to get a better image... who knows, maybe there is something hidden that I didnt bring out.

Cheers
Wayne
You should also seriously consider joining the Astronomical Society of Vic. The planetary and astrophotography section runs lots of workshops online showing members how to capture great planetary images.

Cheers.
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Old 13-10-2020, 10:36 AM
evltoy (Wayne)
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Getting better with Advice

Hi John K

Thanks you for pointing me in the direction of a club. I have MBO about 10-15mins away from me so I was looking at joining down the track.

On Sunday night I had "some" breaks in the sky. It wasn't ideal, but I was keen to get out there and try some of the advice I was given. The sky did have clouds passing and you can see them on the Histogram when recording. Also the seeing was poor as I can see the stars where clear and bright but twinkling like crazy.

Anyways.. that night I took my time trying to get tracking as best I could and put in more time and effort into my focusing.

Here is what I ended up with. Not putting Mars up as it was a distorted Red blob!
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