M42 again

CCD vs Film? Lots of time vs no patience? Alright, this is your place to discuss all the astrophotography what's and what's not. You can discuss about techniques, accessories, cameras, whatever....just make sure you also post some nice photos here too!
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weixing
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M42 again

Post by weixing »

Hi,
This is my another attempt on M42(best for testing :) ). The polar alignment is not accurate, so star trail appear on the images... :P Anyway, I'm using WO-4337 40mm eyepiece adapter, so magnification is around 38x. Below are the camera setting:

METERING : SPOT
MODE : M
APERTURE : F3.2
EXP +/- : 0.0
FOCAL LENGTH : f14.0mm(X1.0)
IMG ADJUST : STANDARD
SENSITIVITY : ISO400
WHITEBAL : SUNNY
SHARPNESS : OFF
DATE : 18.01.2004 00:22
QUALITY : 2272x1704 FINE
SATURATION : 0
FOCUS AREA : CENTER

All the images uses the above setting with different exposure. The first images is my attempt on using RegiStax to stack all 6 M42 images I capture.

Also, I discover that the maximum exposure I can go at my site near Tampines Stadium before light pollution will appear in the image is around 60++ seconds. You can see that the M42 at 90 seonds exposure got a brighter background.

By the way, I just download another noise reduction software and hope I can do a better noise reduction using it. I will update once I learn how to use it. :)
Yang Weixing
:mrgreen: "The universe is composed mainly of hydrogen and ignorance." :mrgreen:
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Post by blurblock »

When will you go stargazing the next time? I live in Tampines and been wanting to learn from the old birds ;)
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Grievous
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My attempt on M42..too!

Post by Grievous »

Good morning guys,

Took the following picture just now, obviously, my polar alignment is way off, so i gotta need someone to teach me how to do it again :( Not as great as Weixing's, enjoy~ *yawnz*

Charlie
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Or i shall with bent and turned,
fall me down, distraught..To die.
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VinSnr
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Post by VinSnr »

here is mine........

Image
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Post by Grievous »

ISO1600?! Wouldnt it induce grains and more noise? But your shot looks great! Good tracking mount+ good polar alignment + blardy good digicam + Good location = WoW.

Mine's taken on my heavily light polluted multi-storey carpark..and my image isnt focused enough...which explain the soft texture...*sigh*
Nvm!~ Will try again tonight! Happy Chinese New Year!

Charlie
The gentle light of a distant galaxy
must needs pour into mine eye.
Or i shall with bent and turned,
fall me down, distraught..To die.
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Airconvent
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Post by Airconvent »

mmm...it must be the tracking for the ETX is not good enough for long exposures. I took some M42 shots that day and they were practically useless.
I have attached them here for academic reasons.
You can just barely make out the half donut nebula.

The 1st one with NR on. At exposures less then 10 secs, you actually see nothing! The 2 pics, if memory serves is about 25-40 seconds exposure.

The 2nd one was taken with NR off (notice the reddish background). I wonder if I should use a broad band filter, will the reddish tinge disappear but I suppose the nebulosity would be further subdued?

rich
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Grievous
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Post by Grievous »

Well, managed to learn polar alignment good enough, so here's my attempts again (with rough processing as again, no time to commit!!) :

M42: 130 stacks of 8 secs, ISO200. Taken through Antares Ortho 12.5mm
Photoshop - unsharp mask, despeckle.

Jupiter, Saturn: 60 stacks of 1/8secs at ISO100. Taken through Tak Hi-Ortho 4mm.

Personally, i think the M42 is great, quite an achievment actually :)

Happy CNY,
Charlie

P.S: Men in SingAstro eligible to give out red packets that i _may_ know - Richard, CC, KayHeem, VinSnr, Chuang Yee(?), Mattew(?), Wira(???).
So whose house shall it be first?
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Airconvent
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Post by Airconvent »

mmmm...in taking astro shots, which ISO is better? higher or lower?
from an emulsion photo point of view, ISO400 is best as it has the largest grains and respond more quickly?
What are the best settings for astro shots? I usually set to shortest possible focal ration as my camera will allow with the longest exposure without being too bright...

BTW Charlie, you are welcome to come to my house to collect the red packet.
Only condition : I only take Orange C5s... oranges ....:-)

rich
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Post by VinSnr »

ISO1600?! Wouldnt it induce grains and more noise? But your shot looks great! Good tracking mount+ good polar alignment + blardy good digicam + Good location = WoW.

Charlie
The Canon DSLRs are known to be very little noise. I could have done dark frame substraction, but when I saw the noise generated...it was so little I didn't see the need.

Get a 10D and see for yourself. You won't believe the noise level.
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VinSnr
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Post by VinSnr »

Airconvent wrote:mmmm...in taking astro shots, which ISO is better? higher or lower?
from an emulsion photo point of view, ISO400 is best as it has the largest grains and respond more quickly?
What are the best settings for astro shots? I usually set to shortest possible focal ration as my camera will allow with the longest exposure without being too bright...

BTW Charlie, you are welcome to come to my house to collect the red packet.
Only condition : I only take Orange C5s... oranges ....:-)

rich
rich, it depends on the objects and the camera

If it's canon 10D, even ISO800 will have no noise. But you can't try that on a normal digicam.

I think the best for planets is around ISO100, 1/8-1/4 seconds exposure is enough. Then stack hell of a lot.
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