Jump to content

Stargazers Lounge Uses Cookies

Like most websites, SGL uses cookies in order to deliver a secure, personalised service, to provide social media functions and to analyse our traffic. Continued use of SGL indicates your acceptance of our cookie policy.

jamesj01

Why are my images partially blurry and how to stop this

Recommended Posts

Hi everyone,

I am new to astrophotography and of course started by taking a photo of the moon (as attached) using my Canon EOS500D camera - 1/250 exposure time, 800ISO. I used my celestron 127EQ telescope with a adapter for the camera of course. I used no eyepiece. 

However, i find that it is slightly blurred, and upon taking pictures of nearby stars, i also found them to be blurred, even with a high exposure time. am i doing anything wrong at all or is this simply because of my setup? 

Many thanks

IMG_3243.CR2

Share this post


Link to post
Share on other sites

I think your focus looks off. If you're having trouble then I would suggest trying a Bahtinov mask.

Share this post


Link to post
Share on other sites
10 hours ago, jamesj01 said:

i also found them to be blurred

Hi 

JTOL. What @MarkAR says and...

Is the telescope OK visually? Is it collimated? Do you have a long lens you could test against?

How do you take the shot? Maybe try without touching the camera. At long focal lengths, even at 1/250s, there will be two images recorded. An image -corresponding to a shutter release- and a second when the camera has settled.

The atmosphere also has to be still. For the moon, probably better to take a video and stack the best frames.

HTH

Edited by alacant

Share this post


Link to post
Share on other sites

@jamesj01 Can you upload the image as a jpeg or png file ? This way the image can be viewed without having to downloaded and can also be viewed on all platforms.

Share this post


Link to post
Share on other sites

.cr2 -> .jpg

HTH

IMG_3243.thumb.jpg.fcc3c2aae5bae8c8f17837c4c64acf13.jpg

Edited by alacant

Share this post


Link to post
Share on other sites

@alacant thanks for the speedy reply - my telescope uses a newtonian reflector and i dont know if it is collimated or not sorry. 

When i look through the eyepiece without a DSLR attached, it is clear as daylight and the detail is amazing for both stars and the moon. It is blurry however through my camera. I strongly go with what you said about my telescope moving when i take my picture so i have purchased a remote. I have heard they are essential. So possibly there is to much movement when i press the shutter button?

Many thanks

Share this post


Link to post
Share on other sites

@MarkAR i will look into that - are they used primarily if you wanted to photograph an object in the sky?

Share this post


Link to post
Share on other sites
5 minutes ago, jamesj01 said:

@alacant thanks for the speedy reply - my telescope uses a newtonian reflector and i dont know if it is collimated or not sorry. 

When i look through the eyepiece without a DSLR attached, it is clear as daylight and the detail is amazing for both stars and the moon. It is blurry however through my camera. I strongly go with what you said about my telescope moving when i take my picture so i have purchased a remote. I have heard they are essential. So possibly there is to much movement when i press the shutter button?

Many thanks

When you look through the eyepiece the moon and stars look clear/sharp. This tells us the focus is ok for that eyepiece. When you then connect your camera how are you focusing the camera? Are you using the live view and then zooming in the get better focus?

Edited by Chefgage

Share this post


Link to post
Share on other sites
Just now, Chefgage said:

When you look through the eyepiece the moon and stars look clear/sharp. This tells us the focus is ok. When you then connect your camera how are you focusing it? Are you using the live view and then zooming in the get better focus?

Yes, when i connect my camera it is in manual mode and i am using the focus knobs on the telescope to achieve the cameras focus

Share this post


Link to post
Share on other sites
1 minute ago, jamesj01 said:

Yes, when i connect my camera it is in manual mode and i am using the focus knobs on the telescope to achieve the cameras focus

Do you then re-focus using the X5 zoom and then again using the X10 zoom in the live view?

Share this post


Link to post
Share on other sites
1 minute ago, Chefgage said:

Do you then re-focus using the X5 zoom and then again using the X10 zoom in the live view?

sorry juts to clarify, the X5 and X10 zoom are the buttons on the camera correct?

Share this post


Link to post
Share on other sites
5 minutes ago, jamesj01 said:

sorry juts to clarify, the X5 and X10 zoom are the buttons on the camera correct?

Yes that's correct. How I focus my camera is to centre a star in the live view screen. I then set the focus by focusing back on forth looking at where the 'sweet spot' is. I then leave the focus on this sweet spot. I then zoom in to X5 on the camera and then repeat the process. Then zoom in X10 and again repeat. You will find at x10 that you only need a very tiny movement of the focuser to change focus.

This process helps dial in the focus so that stars appear sharp.

Share this post


Link to post
Share on other sites
8 minutes ago, Chefgage said:

Yes that's correct. How I focus my camera is to centre a star in the live view screen. I then set the focus by focusing back on forth looking at where the 'sweet spot' is. I then leave the focus on this sweet spot. I then zoom in to X5 on the camera and then repeat the process. Then zoom in X10 and again repeat. You will find at x10 that you only need a very tiny movement of the focuser to change focus.

This process helps dial in the focus so that stars appear sharp.

thats brilliant - thank you will try this tonight :) 

  • Like 1

Share this post


Link to post
Share on other sites

I would do yes. Although I find focusing on the moon easier as you can see surface details which makes it easier to focus as apposed to a point of light like a star.

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now

  • Recently Browsing   0 members

    No registered users viewing this page.

  • Similar Content

    • By endless-sky
      I would like to share my third image.
      I finally had a "lucky week", since my last session, December 18th. I managed 5 clear nights out of the past 6 (has to be a record, at least for me and my area) and I was able to finish a couple of projects I had started long ago and start a few new ones.
      This is M33, also known as the Triangulum Galaxy, taken over 10 nights, under my Bortle 5/6 home sky.
      Total integration time: 10h 14m 00s.
      Here are the acquisition details:
      Mount: Sky-Watcher NEQ6 Pro
      Telescope: Tecnosky 80/480 APO FPL53 Triplet OWL Series
      Camera: D5300 astromodified
      Reducer/flattener: Tecnosky 4 elements, 0.8x
      Guide-scope: Artesky UltraGuide 60mm f/4
      Guide-camera: ZWO ASI 224MC
      2020/11/08: Number of subs/Exposure time: 11@240s. Notes: L-Pro filter, no Moon
      2020/11/09: Number of subs/Exposure time: 10@240s. Notes: L-Pro filter, no Moon
      2020/11/20: Number of subs/Exposure time: 15@240s + 4@300s. Notes: L-Pro filter, Moon 30% illuminated
      2020/11/21: Number of subs/Exposure time: 22@300s. Notes: L-Pro filter, Moon 45% illuminated
      2020/11/24: Number of subs/Exposure time: 20@300s. Notes: L-Pro filter, Moon 75% illuminated
      2020/12/13: Number of subs/Exposure time: 12@300s. Notes: L-Pro filter, no Moon
      2020/12/14: Number of subs/Exposure time: 8@300s. Notes: L-Pro filter, no Moon
      2020/12/18: Number of subs/Exposure time: 6@300s. Notes: L-Pro filter, Moon 20% illuminated
      2021/01/10: Number of subs/Exposure time: 9@300s. Notes: L-Pro filter, no Moon
      2021/01/11: Number of subs/Exposure time: 15@300s. Notes: L-Pro filter, no Moon
      Total exposure time: 36840s = 10h 14m 00s.
      Pre and post-processing: PixInsight 1.8.8-7.

      Image was Drizzle Integrated and then cropped to original sensor size (6016x4016), without resampling. So, it appears as if taken ad double the focal length (768mm instead of 384mm). Image scale 1.04 arc-sec/pixel.
      Here's a link to the full resolution image: Triangulum Galaxy (M33)
      Thanks for looking!
      C&C welcome!
    • By AJ-DE
      Hi All, I have a Star Adventurer but have had problems getting consistent results even when setup was as near to perfect as I can do, (this was focussed on due to this issue).
       
      It took me a while to find out that when the eyepiece is is extended for focus it is very loose, so loose the graticule moves indipendantly of Polaris / background.
       
      I have asked the supplier, "Astroshop.eu", to highlight the problem and ask for their feedback.
       
      Question to Astroshop.eu:
      I have had a constant issue with Polar Alignment. As I cannot use it so often, (visibility), it has taken me a while to identify the problem. When I adjust the polar scope focus the eyepiece is so loose that the graticule moves a lot laterally in all directions in the view. I can send a video but I think you can  understand what I am saying.
      Basically I must be getting something very wrong or there is an issue with the product. The thread is so loose it is entirely unstable.
      Please advise what we can do about this.
       
      Answer from Astroshop.eu:
      1. "I'am sorry to say, but this is very normal and does not affect the function of the star adventurer".
      2. "My collegue confirmed that this will not be a issue".
       
      I have subsequently asked the guy to ask his colleague again, but some time has gone past and I have no further reply.
       
      I think it is clear enough from the text and would really appreciate some experienced answer, any comments very welcome.
      Additionally here are the videos I have sent to show them, (hand holding the phone so a bit shaky but issue can be seen. I'd really appreciate some help before I spend too much time again tring to get it to work, for reference the eyepiece wobble is around 3.5 graticule intervals, so not small. As it's full of grease it took me a long time to see how poor quality the Polarscope build quality is.
       
      https://drive.google.com/file/d/1VC1p30t8n45oS6fkdxjkztrnoR1r7c6x/view?usp=sharing
      https://drive.google.com/file/d/1mjBaecqTmIhXgJUC-dERRYBb-LaryLMN/view?usp=sharing
       
      Thank you all, Andy
    • By Planetarian
      Just thinking how this setup would compare to normal astrophotography setups. Imagine a Nikon coolpix p1000 on an equatorial mount. Has anyone done that yet? 
      As I saw in the YouTube videos about the camera, it has absolutely no chromatic aberration, so I assume it's got apochromatic lens. It's magnification is extremely good (125x with 16MP sensor). The aperture is quite small tho compared to many different refractors available. 
       
      So what do you think about the idea:  astrophotography with a Nikon?  
    • By SpaceDave
      I'm new to the astrophotography hobby. I have experience with astronomy. I am struggling to make decent deep sky images (other than M42). The images don't seem to have much definition or brightness despite a decent overall exposure time. See the below images. I have seen on this forum that people are able to take awesome images of the below objects with my same setup. Is anyone able to tell me if I am missing something, please? Do I need even more exposure time?
      I use a Celestron 6SE with unmodified Canon 600D. It has a goto alt az, no EQ. I use a bahtinov mask to focus. Both images were taken with the native focal length of 1500mm, no filters or eyepieces.
      The image of the Triangulum Galaxy is 180 x 15sec ISO800 images. The Crab Neb is 250 x 15sec ISO800 images. Both images had their appropriate flats, darks and biases (30 of each). I use SIRIL to stack the images, which I have had good success with M42 before (see below).
      Any advice would be appreciated!



    • By FireNIceFly
      Hello, 
      I've been into astronomy since I was young and more recently astrophotography. I've just (finally) got my new telescope, a Celestron AVX 9.25" Edge HD with various accessories including a reducer lens. I'm still trying to get the auto guider up and running as that's being a pain and need to get a dew heater for the telescope (currently lookjng for a decent one). I'm also looking into what filters to get as well as that's still fairly new to me, at least for the astrophotography side. 
      I'm also very much into microscopy and looking at microphotography, I'm currently saving up to get a new microscope. 
      I've also got a facebook group where I share astronomy and science news, where members can share astronomy and science news or their own astro or science images, discuss things, etc. https://www.facebook.com/groups/2494142714158646/?ref=share
      Anyway, hello to all from Cambridge, UK :-) 
       
      Adz



×
×
  • Create New...

Important Information

By using this site, you agree to our Terms of Use.