I get asked about the diffraction spikes in some of my images. Most of them but not all are contrived in photoshop. I have attached a file on "how to" make these. Some folks like them and want to add...some hate them and try to remove. I found this helpful tutorial which comes close to the technique that I use.
For me it depends on the image - since the eye is always drawn to the brightest part of an image - I will add a spike IF A STAR is too bloody bright and ruining the image....I at least try to make it interesting. Which was the case with the Horsehead Nebula.
How to make diffraction Spikes
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nikonshooter wrote:
I get asked about the diffraction spikes in some of my images. Most of them but not all are contrived in photoshop. I have attached a file on "how to" make these. Some folks like them and want to add...some hate them and try to remove. I found this helpful tutorial which comes close to the technique that I use.
For me it depends on the image - since the eye is always drawn to the brightest part of an image - I will add a spike IF A STAR is too bloody bright and ruining the image....I at least try to make it interesting. Which was the case with the Horsehead Nebula.
I get asked about the diffraction spikes in some o... (
show quote)
sort of a manual Topaz star effects - I like it! Good to know the tricks!
:thumbup:
nikonshooter wrote:
I get asked about the diffraction spikes in some of my images. Most of them but not all are contrived in photoshop. I have attached a file on "how to" make these. Some folks like them and want to add...some hate them and try to remove. I found this helpful tutorial which comes close to the technique that I use.
For me it depends on the image - since the eye is always drawn to the brightest part of an image - I will add a spike IF A STAR is too bloody bright and ruining the image....I at least try to make it interesting. Which was the case with the Horsehead Nebula.
I get asked about the diffraction spikes in some o... (
show quote)
Again that is really nice to know Ed.
Craig
nikonshooter wrote:
I get asked about the diffraction spikes in some of my images. Most of them but not all are contrived in photoshop. I have attached a file on "how to" make these. Some folks like them and want to add...some hate them and try to remove. I found this helpful tutorial which comes close to the technique that I use.
For me it depends on the image - since the eye is always drawn to the brightest part of an image - I will add a spike IF A STAR is too bloody bright and ruining the image....I at least try to make it interesting. Which was the case with the Horsehead Nebula.
I get asked about the diffraction spikes in some o... (
show quote)
Interesting to know, but once you see how easy it is with Topaz's Star Tool, you'll never look back.
JimH123 wrote:
Interesting to know, but once you see how easy it is with Topaz's Star Tool, you'll never look back.
I'm also a big Fan of the Topaz Tools.
Craig
CraigFair wrote:
I'm also a big Fan of the Topaz Tools.
Craig
I have heard a lot of good things about Topaz plugins.
nikonshooter wrote:
I have heard a lot of good things about Topaz plugins.
Right now I have the Detail3 and DeNoise and want to get Clarity too.
You can get them individually or in the Bundle.
But there some of them I wouldn't use that often if ever.
I am of the camp that I find them distracting and often they show a flaw in my imaging system. I see all these plugins from Anne's set to Carboni's, I have the full set, but was unaware of the capabilities in Topaz, all I want is a simple action to effectively diminish or at the very least tone them down.
I know many like them, and hey the Hubble has them, the only suggestion I would say is that if you are going to use to use them, since they will put the diffraction spikes exactly straight up and down that you should skew your image just a little bit by rotating no more than 10 degrees, then once the diffraction spikes are placed straighten your image.
this technique makes it much harder to detect that it's a plugin without going super close up and looking at all the other stars for slight aberrations. or you could go old school like I was shown by using two pieces of yarn, to create a makeshift mirror vane across my old SCT.
Matthew
SonnyE
Loc: Communist California, USA
You could do like Sonny does...
Forget you have the Bahtinov mask on and marvel at the pictures you are getting.... :shock: :lol:
I'm crushed. All this time I thought it was because of the type of scope being used.
I get odd ones with my 6" Newtonian. I think the secondary is maybe not centered correctly even though my laser comes in where it should during collimating. It arrived with the secondary very loose and moving about.
Albuqshutterbug wrote:
I'm crushed. All this time I thought it was because of the type of scope being used.
I get odd ones with my 6" Newtonian. I think the secondary is maybe not centered correctly even though my laser comes in where it should during collimating. It arrived with the secondary very loose and moving about.
Any scope with a secondary mirror held by vanes will produce these artifacts unless some means have been applied to eliminate them, like using curved vanes. Some have ground or filed down the vanes trying to minimize this effect. I wanted to get a curved vane but it seems these are predominately made for larger scopes.
Can you describe or better yet show a pic of the odd spikes we might be able to track down the culprit, usually it is miscollimation.
Matthew
Oknoder wrote:
Any scope with a secondary mirror held by vanes will produce these artifacts unless some means have been applied to eliminate them, like using curved vanes. Some have ground or filed down the vanes trying to minimize this effect. I wanted to get a curved vane but it seems these are predominately made for larger scopes.
Can you describe or better yet show a pic of the odd spikes we might be able to track down the culprit, usually it is miscollimation.
Matthew
http://flic.kr/p/vyk6J8It's not symmetrical. The flairs on the side are not right.
I hate doing inspection from a small phone screen. Looking at ur image, BTW nice capture. since both object that are bright enough to create diffraction spikes show the same type of artifact, only difference is the side of the object. I'll venture a guess it has to do with coma or the field not being flat.
I'm also wondering with your mirrors being perfectly collimated, could it be that your veins are slightly out of whack and you're catching light bleed off from the side your vein.
Damn auto-correct,
Matthew
SonnyE
Loc: Communist California, USA
Oknoder wrote:
I hate doing inspection from a small phone screen. Looking at ur image, BTW nice capture. since both object that are bright enough to create diffraction spikes show the same type of artifact, only difference is the side of the object. I'll venture a guess it has to do with coma or the field not being flat.
I'm also wondering with your mirrors being perfectly collimated, could it be that your veins are slightly out of whack and you're catching light bleed off from the side your vein.
Damn auto-correct,
Matthew
I hate doing inspection from a small phone screen.... (
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My veins are slightly out of whack.
So are my Arteries, one has a stint, and another needs a stint.
But my HMO would prefer I die. If it isn't 80% blockage, no go. Mine is a mere 70%.
My HMO is like Congress, they don't do anything unless their heads are on fire and their asses are catchin.
Imagine variable vanes in a Newtonian. Spiral to accentuate the spires...
Of course you could just face goo the image....
IDK, I think Congress does exactly what it's supposed to do, in the most efficient way possible, because what is the opposite of progress?
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