Shooting through bad glass

[jjjnettie (Jeanette)]

Sigma 70-300mm f4.5 lens @ 200mm
2 hours and 40 min of 10min subs.

What's that saying???
"Life's too short to be shooting through bad glass".

At least I have a heap of 10min darks to add to my library.

Just look at the left side of the image. ewww

[leon]

Na JJJ the saying is "Life is to short to look through bad glass" and that saying is mine JJJ, yep see the signature. , but it is OK you can use it.

However not that bad of a shot, a bit overly bright but pretty good.

Leon

[jjjnettie (Jeanette)]

LOL there is only about 1/5th of the image that is actually sharp and without coma.
And I did use some poetic license with your quote.

[mswhin63 (Malcolm)]

Ouch, Had the same problem last night.

[gbeal]

Not too flash, I have to admit. More so on one side though, why?
Similar result for me as well, tinkering with a shot or two between the showers and the TV reducer didn't like being 60mm from the chip, I got warp factor 4 in each corner. Back to the drawing board. Nice doodad though.
Gary

[h0ughy (David)]

jjj i think it is the stacking function - try a different setting

[jjjnettie (Jeanette)]

Originally Posted by h0ughy

jjj i think it is the stacking function - try a different setting

Here's a single image. Not even the Distort-Lens Correction function can help with this one.

[h0ughy (David)]

wow thats huge in distortion. its like the focal plane is not falling on the chip. i did stacking once before and had a result like yours but now i see it is the lens

[jjjnettie (Jeanette)]

Originally Posted by h0ughy

i did stacking once before and had a result like yours but now i see it is the lens

I have 5hrs of Rho Oph. that did that too.
Tried to combine 2 nights work. Separately they're fine, but they just won't stack up together.
Did you ever fix the problem?

[DavidU (Dave)]

May be a lens element is tilted.

[h0ughy (David)]

Originally Posted by jjjnettie

I have 5hrs of Rho Oph. that did that too.
Tried to combine 2 nights work. Separately they're fine, but they just won't stack up together.
Did you ever fix the problem?

yeah i use pixinsight for combining different sessions

[irwjager (Ivo)]

Originally Posted by jjjnettie

Here's a single image. Not even the Distort-Lens Correction function can help with this one.

Hi JJJ,

Maybe there's a better lens distortion correction plug-in for PS available? It sounds like the one that comes with PS is only for subtle distortions...
I was able to do quick correction that looks semi-ok with ST (probably good enough for stacking), so there may be hope for this data set yet!

Ivo

[multiweb (Marc)]

Originally Posted by DavidU

May be a lens element is tilted.

Yeah that's what I thought too. Something nasty going on in there. The right side of the field shows some uneven reflection/illumination as well. Shame coz it's a nice shot.

[renormalised (Carl)]

Either as Dave said, something's out of kilter, or that lens is a shocker.

[jjjnettie (Jeanette)]

LOL That lens is a shocker. yep yep yep
But I had to give it a chance before relegating it to the bottom of the camera bag.

[erick (Eric)]

It's got nothing on the $5 CCTV lens I bought off Ebay for my Gstar. But that wasn't bad glass, it was bad plastic (Got a much better Japanese KOWA lens now. Looking forward to when I get the first chance to point that at the sky.)