Please...no more diffraction spikes in refractor and SCT shots

They may look "pretty" but they are still silly.
Why compromise the resolution of a good refractor
with those things?
-Rich

RichA wrote:

They may look "pretty" but they are still silly.
Why compromise the resolution of a good refractor
with those things?

Examples?


Tim
--
This is not my signature.

Examples?


Tim

There was a photo in Sky and Telescope a while back that was reputedly taken
with a 60mm TAK refractor. However it had definite diffraction spikes around
at least one bright star.

Myself and many others apparently noticed this and Emailed Sky and Telescope
about it.

Their response was that they folks doing the imaging had placed something over
the objective to produce those spikes because they thought they looked slick.

Well, I guess that's one possible explanation, personally I would not be
surprised if there was actually another explanation to those spikes.

Jon

I've read about refractor owners putting an hexagonal mask over the
objective to aid in splitting close double stars.

Best regards,
Bill
"Jon Isaacs" wrote in message
...
Examples?


Tim

There was a photo in Sky and Telescope a while back that was reputedly
taken
with a 60mm TAK refractor. However it had definite diffraction spikes
around
at least one bright star.

Myself and many others apparently noticed this and Emailed Sky and
Telescope
about it.

Their response was that they folks doing the imaging had placed something
over
the objective to produce those spikes because they thought they looked
slick.

Well, I guess that's one possible explanation, personally I would not be
surprised if there was actually another explanation to those spikes.

Jon

Ooops...SCTs as well.

"Jon Isaacs" wrote in message
...
Examples?


Tim

There was a photo in Sky and Telescope a while back that was reputedly
taken
with a 60mm TAK refractor. However it had definite diffraction spikes
around
at least one bright star.

Myself and many others apparently noticed this and Emailed Sky and
Telescope
about it.

Their response was that they folks doing the imaging had placed something
over
the objective to produce those spikes because they thought they looked
slick.

Well, I guess that's one possible explanation, personally I would not be
surprised if there was actually another explanation to those spikes.

Jon

I have a crosstar filter for some of my 35mm SLR lenses. Makes for some
interesting shots of sunlight hilites on water, sunlit dewdrops, or at
Christmas time, when a lit Christmas tree is in the photo. Never used it
for astrophotos, though, back when I had an interest in capturing the
universe on film...

Of course, I always preferred the stars to look like... stars...

--
Jan Owen

To reach me directly, remove the Z, if one appears in my e-mail address...
Latitude: 33.662
Longitude: -112.3272

"Jon Isaacs" wrote in message
...
Examples?


Tim

There was a photo in Sky and Telescope a while back that was reputedly
taken
with a 60mm TAK refractor. However it had definite diffraction spikes
around
at least one bright star.

Myself and many others apparently noticed this and Emailed Sky and
Telescope
about it.

Their response was that they folks doing the imaging had placed
something over
the objective to produce those spikes because they thought they looked
slick.

Well, I guess that's one possible explanation, personally I would not be
surprised if there was actually another explanation to those spikes.

Jon

Could you be seeing blooming of a CCD image caused by bright stars?

RichA wrote:
They may look "pretty" but they are still silly.
Why compromise the resolution of a good refractor
with those things?
-Rich

On Fri, 17 Dec 2004 23:56:45 +0000, Tim Auton
wrote:

RichA wrote:

They may look "pretty" but they are still silly.
Why compromise the resolution of a good refractor
with those things?

Examples?


Tim

If you have access, check out the nice Pleiades shot on
the astromart imaging group. Nice diffraction spikes,
and it was done with a Tak FSQ106.

On 17 Dec 2004 19:58:17 -0800, wrote:

Could you be seeing blooming of a CCD image caused by bright stars?

RichA wrote:
They may look "pretty" but they are still silly.
Why compromise the resolution of a good refractor
with those things?
-Rich

No. It's a new plague of a trendiness in astro pictures.
I admit, you see the Pleiades with little spikes, suffused in
the nebulas, and it makes me kind of nostagic for when most
people shot deepsky with Newtonians, but it detracts from the
purity of the shot when you know you can do it without the
spike interference because refractors and SCTs do not use
spiders.
-Rich

RichA wrote:

On 17 Dec 2004 19:58:17 -0800, wrote:



Could you be seeing blooming of a CCD image caused by bright stars?

RichA wrote:


They may look "pretty" but they are still silly.
Why compromise the resolution of a good refractor
with those things?
-Rich


Rich,

No. It's a new plague of a trendiness in astro pictures.
I admit, you see the Pleiades with little spikes, suffused in
the nebulas, and it makes me kind of nostagic for when most
people shot deepsky with Newtonians, but it detracts from the
purity of the shot when you know you can do it without the
spike interference because refractors and SCTs do not use
spiders.

People add some string across the dew cap to generate these patterns. At
the risk of being trite, it is being done on purpose for effect and
nothing else.

Anthony.

-Rich