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Astrophotography and Sketching >> DSLR & Digital Camera Astro Imaging & Processing

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Falcon-
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Reged: 09/11/09

Loc: Gambier Island, BC, Canada
Diffraction spike collection - add yours!
      #5676092 - 02/12/13 03:32 PM Attachment (25 downloads)

Inspired by this post regarding spikes from a camera lens I started hunting up examples of diffraction spikes from my various lenses. Rather then go (somewhat) off topic there I figured I would start a new thread.

So here it is, a somewhat random collection of examples of diffraction spikes my optics have produced over the years.

Please post some examples of your own!

Edit: the 44M-4 is really at f/5.6 not f/5.8 - but kinda hard to correct it after you toss out the "temporary" document I used to add the text to the image.

Edited by Falcon- (02/12/13 03:35 PM)


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nwinston
sage
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Reged: 02/10/10

Loc: Maryland, USA
Re: Diffraction spike collection - add yours! new [Re: Falcon-]
      #5676221 - 02/12/13 04:35 PM Attachment (28 downloads)

Here's my collection:

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Falcon-
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Reged: 09/11/09

Loc: Gambier Island, BC, Canada
Re: Diffraction spike collection - add yours! new [Re: nwinston]
      #5676360 - 02/12/13 05:53 PM

Neil: Spikes from an 80ED? Interesting! Screws in the optical path?

How do you find the 70-200 f/4L? I recently picked up one of those myself but not had the chance to use it for astro yet.


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nwinston
sage
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Reged: 02/10/10

Loc: Maryland, USA
Re: Diffraction spike collection - add yours! new [Re: Falcon-]
      #5676463 - 02/12/13 07:30 PM Attachment (16 downloads)

It's not a screw in the optical path. I've had a screw that was too long in the optical path before, and the spikes were much larger and totally different looking. I'm not sure exactly what they are, but I think the spikes are caused by three little flat spacers or holders that are along the edge the front element. I attached a picture of one of them.

I like my 70-200 F/4L. It's okay at F/4, and when stopped down to F/5.6 it's pretty sharp. Very good for a zoom lens.


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jwheel
professor emeritus


Reged: 01/23/08

Loc: Fort Davis TX
Re: Diffraction spike collection - add yours! new [Re: nwinston]
      #5676523 - 02/12/13 08:14 PM

http://www.flickr.com/photos/23614320@N00/3267944035/in/set-72157600237071127/

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Dave Venne
member
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Reged: 11/12/07

Loc: Burnsville, MN, USA
Re: Diffraction spike collection - add yours! new [Re: Falcon-]
      #5676772 - 02/12/13 11:10 PM Attachment (16 downloads)

Overhead power lines. Thank goodness they're parallel to each other.

Sorry if this is a bit off-topic, but they're a permanent part of my optical train.


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Falcon-
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Reged: 09/11/09

Loc: Gambier Island, BC, Canada
Re: Diffraction spike collection - add yours! new [Re: Dave Venne]
      #5676800 - 02/12/13 11:26 PM

Not off topic at all, those *are* diffraction spikes after all!

Interesting effect. I wonder what would happen if you just put a small wire in front of your scope/lens perpendicular to the direction of the power lines to make that into a 4-point star instead of 2 point.


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Dave Venne
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Reged: 11/12/07

Loc: Burnsville, MN, USA
Re: Diffraction spike collection - add yours! new [Re: Falcon-]
      #5676834 - 02/12/13 11:56 PM

Quote:

I wonder what would happen if you just put a small wire in front of your scope/lens perpendicular to the direction of the power lines to make that into a 4-point star instead of 2 point.




It'd probably never look quite right...one pair would be thicker, and getting them perpendicular would be difficult. Besides, it's sort of a signature on my images. I'll keep it just the way it is. Although if the power company decides to bury the lines that would be fine with me.


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mmalik
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Reged: 01/13/12

Loc: USA
Re: Diffraction spike collection - add yours! new [Re: Falcon-]
      #5677011 - 02/13/13 03:54 AM Attachment (14 downloads)

I hardly ever see diffraction spikes in my images; here is one I could find. (Alberio)

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Campos
Vendor-MonoMods


Reged: 12/26/12

Loc: Portugal
Re: Diffraction spike collection - add yours! new [Re: Falcon-]
      #5677033 - 02/13/13 05:01 AM Attachment (14 downloads)

Hi there,

I have big ones!...Difraction spykes that is

Here's an image I made in 2011 of the horsie with huge spykes from Alnitak.

Greets,

Luís


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Tonk
Postmaster
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Reged: 08/19/04

Loc: Leeds, UK, 54N
Re: Diffraction spike collection - add yours! new [Re: Campos]
      #5677157 - 02/13/13 07:49 AM

I get multicoloured ones



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bilgebay
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Reged: 11/06/08

Loc: Türkiye - Istanbul and Marmar...
Re: Diffraction spike collection - add yours! new [Re: Tonk]
      #5677197 - 02/13/13 08:25 AM

Tony, it is the first time I am seeing a photo of yours and it is a beauty!

You should post more often!


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jwheel
professor emeritus


Reged: 01/23/08

Loc: Fort Davis TX
Re: Diffraction spike collection - add yours! new [Re: bilgebay]
      #5677350 - 02/13/13 10:14 AM Attachment (11 downloads)

Here is an odd pattern that captured last year when imaging Venus and The Pleiades:

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Hilmi
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Reged: 03/07/10

Loc: Muscat, Sultanate of Oman
Re: Diffraction spike collection - add yours! new [Re: jwheel]
      #5677380 - 02/13/13 10:34 AM

jwheel,

Now that's a funky pattern. Looks like an 80's circular wall paper pattern.


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Tonk
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Reged: 08/19/04

Loc: Leeds, UK, 54N
Re: Diffraction spike collection - add yours! new [Re: Hilmi]
      #5677515 - 02/13/13 11:39 AM

Quote:

Tony, it is the first time I am seeing a photo of yours and it is a beauty! You should post more often!




Thats because I stopped processing new images 3 years ago while doing my PhD - I had to exert some serious discipline else work would come second. I have to confess that I actually started processing again last week as my back log is now enormous!! (I didn't stop imaging)

See here


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pfile
Post Laureate


Reged: 06/14/09

Re: Diffraction spike collection - add yours! new [Re: Hilmi]
      #5677650 - 02/13/13 01:01 PM

Quote:

jwheel,

Now that's a funky pattern. Looks like an 80's circular wall paper pattern.




i've seen this when taking pictures toward the sun with my iPhone. i think it might be reflections of the microlenses over the sensor.


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srosenfraz
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Reged: 03/06/11

Loc: United States
Re: Diffraction spike collection - add yours! new [Re: Tonk]
      #5678013 - 02/13/13 05:02 PM

Some really nice images in your collection. So, are you Dr. Tonk now? (if so, congrats!)

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