Astrophotography 1

[Ian]

1150mm F4.5
Hypered EGP-400
60 min exposure.

[Flare]

Hose head nebula~ One of the most commonly shot object in the night sky...

[isomers007]

Quote: Originally posted by Flare Hose head nebula~ One of the most commonly shot object in the night sky...

horsehead and hose head same izzit? i always refer this to horsehead nebula... anyway...this one is de dark nebula type, rite? juz clouds of dust which blocks de light from behind...btw, nice pic!

[Ian]

Quote: Originally posted by isomers007 horsehead and hose head same izzit? i always refer this to horsehead nebula... anyway...this one is de dark nebula type, rite? juz clouds of dust which blocks de light from behind...btw, nice pic!

The actual Horsehead (Barnard 30) is a dark nebula, however it's surrounded by IC 434 which is a reflection nebulae (the red bit) which is illuminated by Sigma Orionis. To the lower left is NGC 2023 that is a large reflection nebula.

Quote: Originally posted by Flare Hose head nebula~ One of the most commonly shot object in the night sky...

Actually it's one of the most commonly attempted objects, very few shots of it are successful due to it being all but impossible to see the Horsehead visually.

[kylelam77]

woh.....Very nice. No comments on the type of stuff u guys are talking abt tho. totally clueless even tho i think astronomy is interesting. Great Pic!

[eadwine]

goood goood can someone teach me how to take such pictures??? =D

[isomers007]

i think de 1st thing u muz have is a telescope

[copland]

Quote: Originally posted by isomers007 i think de 1st thing u muz have is a telescope

Not to mention a lot of patience... 60 minutes exposure.

[Ian]

Quote: Originally posted by eadwine goood goood can someone teach me how to take such pictures??? =D

Sure, all you need is a telescope that can take a camera and is of a good sized aperture, siderial drives to allow tracking, mirror lock up on the camera, a temperature controlled vaccum chamber with the right gas mixture to modify the flim, plus the perquisite astronomy and photography knowledge and a decade or two of practice and you'll be able to take a shot like the one above

[Wai]

Quote: Originally posted by Ian a temperature controlled vaccum chamber with the right gas mixture to modify the flim

wah...like that also can? this is hardcore..

Afocal projection?

[Klause]

Whao very nice! Ian, how much did you spend on the setup? Just curious, I heard that Astrophotography is an expensive hobby.

[djork]

Quote: Originally posted by Verre Vrai Afocal projection?

prime focus.

[roygoh]

Hi Ian,

Recently I started to have an itchy hand to give astrophotography a try. Hope that I can get some advice and pointers from you.

It all started when I saw a Meade DS-80AT scope on sale at a local Costco for US$199. This is a 80mm dia, 900mm FL (f/11 ?) refractor. It came with the Auto-Star navigator that can automatically point the telescope at a huge number of objects in the sky at the punch of a feww buttons. That is, if I can successfully align and train the scope first...

Anyway, the eyepieces that came with the scope are pathetic 0.96" type, so I looked around the internet and saw the William Optics DCL-28 24mm Plossl eyepiece that has a 28mm thread so that it can be attached sirectly to a CP995. I ordered that after reading some good reviews on dpreview.

Unfortunately, the scope is fitted with a 0.96" focuser, so I also went ahead to buy a 0.96" - 1.25" adapter.

While waiting for the eyepiece and adapter to arrive this week, the weather in Seattle has decided to go back to "normal" this few days, that is, cloudy and drizzling non-stop. Before I get a chance to take the first step, I would appreciate some advice from you.

The DCL-28 eyepiece will provide a magnification of approximately 37.5x with the DS-80. The optimal focal length of the CP995 in macro mode is about 70~100mm (35mm equivalent). That means that I can get an equivalent focal length of 2625~3750mm.

I know it will be relatively easy to get a full-frame shot of the moon with this setup. Is this good enough for photographing the farther planets like Jupiter and Saturn?

Have you had any experience wih Meade's autostar tracking? Will it track the planets smooth enough for photography?

Is the 0.96" focuser going to cause significant vignetting?

Hopefully, I can get enough experience in shorter than 20 years
and progress to SLR photography. I guess the FM10 body should be the best candidate among the equipment I own for this purpose. Do I absolutely have to toss the 0.96" focuser and go for 1.25 or 2" if I want to have any success with SLR astrophotography?

I know the DS-80 is quite a modest scope, but what exactly would be its limitations?

Sorry for throwing such a big bunch of questions. You are the only person I "know" who is experienced in this.

In the mean time, I am doing my job in reading up as much as possible from the internet. Found a site www.astropix.com that has pretty good information for beginners.

Thanks!

Roy

wow... thats cool... does it really exist?

[ckiang]

The pic disappeared.

Regards
CK

[Wai]

Quote: Originally posted by ckiang The pic disappeared. Regards CK

i cleared my cache and i refresh...still can see leh...

[ckiang]

Quote: Originally posted by Wai i cleared my cache and i refresh...still can see leh...

I can see it now. Probably some intermittent network problem. Yes, this is indeed a very spectacular shot!

Regards
CK

[Ian]

Quote: Originally posted by Klause Whao very nice! Ian, how much did you spend on the setup? Just curious, I heard that Astrophotography is an expensive hobby.

IT depends how you want to price the entire system, if you include all my scopes and the special hand built MF astrocamera and the 300/2 lens then it's well in the 6 digit range. Take out the 300/2 and custom astrocamer and it's back in the 5 digit range.

Quote: Originally posted by djork prime focus.

The shot was actually taken at the Schmidt Cassegrainian Focus position, a position that is frequently misrepresented by people who should know better, for example writers for the major astronomy magazines whom incorrectly refer to it as 'prime focus'.

The fact is that 'prime focus' refers to the primary focus point of the first lens or mirror in the optical system, so in the case of a refractor it is where the eyepiece is situated. With a Newtonian or Cassegrain design (including Schmit and Maksutov variations) the real "prime focus" is located at the point where the secondary mirror is placed.

Quote: Originally posted by seamon wow... thats cool... does it really exist?

It's actually a gas/dust pillar that exists, however how it appears to an observer will depend on their position relative to the pillar. From Earth at present it looks like the shot above, in 100,000 years time it will look different no doubt.

[Ian]

Quote: Originally posted by roygoh Hi Ian, Anyway, the eyepieces that came with the scope are pathetic 0.96" type, so I looked around the internet and saw the William Optics DCL-28 24mm Plossl eyepiece that has a 28mm thread so that it can be attached sirectly to a CP995. I ordered that after reading some good reviews on dpreview. Unfortunately, the scope is fitted with a 0.96" focuser, so I also went ahead to buy a 0.96" - 1.25" adapter. The DCL-28 eyepiece will provide a magnification of approximately 37.5x with the DS-80. The optimal focal length of the CP995 in macro mode is about 70~100mm (35mm equivalent). That means that I can get an equivalent focal length of 2625~3750mm. I know it will be relatively easy to get a full-frame shot of the moon with this setup. Is this good enough for photographing the farther planets like Jupiter and Saturn? Have you had any experience wih Meade's autostar tracking? Will it track the planets smooth enough for photography? Is the 0.96" focuser going to cause significant vignetting?

Quote: Originally posted by roygoh Hopefully, I can get enough experience in shorter than 20 years and progress to SLR photography. I guess the FM10 body should be the best candidate among the equipment I own for this purpose. Do I absolutely have to toss the 0.96" focuser and go for 1.25 or 2" if I want to have any success with SLR astrophotography? I know the DS-80 is quite a modest scope, but what exactly would be its limitations? Sorry for throwing such a big bunch of questions. You are the only person I "know" who is experienced in this.

I'd not expect there to be much vignetting with your digicam, if there is then there's not much you can do about it anyway. Vignetting with an SLR typically occurs even with a 2" focuser on most scopes. I did some calculations for a 10" scope and found the optimal focuser for astrophotography was 2.75" inner diameter, which is a bitch as no one makes one in that size.

In all honesty don't expect much from the Meade Autostar system, it works, but Meades performance claims are pretty optimistic to say the least. The amount of Periodic Error in their worm and wheel sets on all of their scopes is pretty crappy, to the point where even with a near perfect polar alignment quite a bit of hand correcting is required for decent astrophotography. (side note, for pin point stars you require sub 5 arc second tracking in RA and Dec over the entire life of the exposure. The typical errors on a meade LX50-200 are around +/- 60 arc seconds per 8 minutes that one revolution of the worm requires. The problem gets worse for smaller and cheaper scopes. Such tracking systems are fine however for visual use.

To put things in perspetive, Opticraft and a couple of european manufacturers can provide sub 5-10 arc second error worm/wheel sets, at a cost of a couple of thousand US per axis minimum.

I'd recommend an old F or F2 body for astrophotography, doesn't have to be in good cosmetic shape as having interchangable screens is pretty much a must. The old OM bodies are also excellent candidates (I use both).