Help, advice needed

[MGSteve]

Hi guys, another noob with a 'What xx do I need' thread I'm afraid.

I'm going to try and get onto the Astrophotography scene this year. Been talking about it for ages, but never got around to it.

Anyway, I've got the camera! - Canon 400D. However, what I don't have is the telescope, mount & adapters. Basically the main stuff!

I've tried taking photos of the sky with the camera & tripod, but of course at the very least I need an motorised equatorial mount so I can do long exposures.

So, that brings me here and in need of a bit of advice.

I don't mind a cheapish reflector to start off with, but the mount is the important thing as I obviously want to take long exposures with it. I also need to know what I need to connect the camera up to it. I've seen all sorts of adapters around, but a pointer in the right direction would be fantastic!

Any help, advise or pointers you could give would be very gratefully received

[Zakalwe]

What type of photography do you want to do? Lunar/planetary or deep sky?

in both cases, you will need a T-ring and adapter to mount the camera to the scope.

If Lunar/planetary, then a reflector is spot on. Long focal length (SCT?), big aperture and a webcam. Fork mount is fine

If DSO work, then:

Equatorial mount

Short focal length 'scope. A refractor seems to be the weapon of choice here.

Some form of guiding setup (either stand-alone or a short scope with guide camera).

I have spent some time speaking to Steve at FLO this morning. Very helpful and knowledgeable chap:icon_salut: . I am starting down the DSO imaging and am building up the kit at the moment. A 80mm Skywatcher Equinox is on its way to me. Following the convrsation this morning, I will be opting for the EQ6 Syntrek mount (I am choosing to invest in the mount as it will probably outlast the 'scope as I upgrade). Guiding will be taken care of by a (yet undecided which one to go for) camera mounted on an ED80 refractor.

[MGSteve]

I will be opting for the EQ6 Syntrek mount (I am choosing to invest in the mount as it will probably outlast the 'scope as I upgrade).

Holy starquakes - I thought £250 was expensive for a mount! It does look the business though.

As for what type of photography I'll be doing - bit of everything really. I can't go too wide angle though (comparatively speaking) thanks to the light pollution here, so mostly planetary, lunar (as far as possible), DSO - that sort of thing really.

All I'm interested in for now is a reasonably good telescope, decent mount (i.e. one that is pretty accurate on the tracking speed, no point having one otherwise) & the Adapter so I can take photos of what I'm looking at.

Do adapters on the whole fit different telescopes & how are the telescopes for mount compatibility? Are there pretty common standards or do you have to watch out for different things when you buy them?

[Zakalwe]

Holy starquakes - I thought £250 was expensive for a mount! It does look the business though.

As for what type of photography I'll be doing - bit of everything really. I can't go too wide angle though (comparatively speaking) thanks to the light pollution here, so mostly planetary, lunar (as far as possible), DSO - that sort of thing really.

All I'm interested in for now is a reasonably good telescope, decent mount (i.e. one that is pretty accurate on the tracking speed, no point having one otherwise) & the Adapter so I can take photos of what I'm looking at.

Do adapters on the whole fit different telescopes & how are the telescopes for mount compatibility? Are there pretty common standards or do you have to watch out for different things when you buy them?

For planetary work a modified webcam is the way to go. Using a DSLR means that you only get single images. using a webcam means that you can get hundreds of frames and "stack" them in a program (such as Registax). This brings out the detail and negates some of the effects of poor seeing.

The dichotomy when doing both types is that planetary and DSO works each needs the opposite of each other. DOS stuff needs a fast, short focal length scope, whilst planetary needs a long focal length.

You can do DSO on a long scope...I have started to use a focal reducer on my 8" SCT (my baby steps are here), but you will be limited by the long focal length (the longer the focal length, the more accurate the guiding has to be. Also, longer focal length 'scopes need longer exposures, which exacerbates the mount and guiding issue)). I have opted to invest in a dedicated DSO imaging rig though, and use my Nexstar for visual and planetary imaging.

I guess it all depends on what level you are going for (and the budget that you have available). Ultimately, there will always be a better, more expensive rig available...you have to choose the best compromise that you are happy with.

One thing is for sure though....you have come to the right place. There are loads of very knowledgeable and helpful people in this 'ere parish.....I have learned loads (but still know [removed word] all!) in a short space of time here.

[rowan46]

Steve can I recommend a book its called "making every photo count" it may save you buying the wrong stuff its available from our sponsor and is very useful to anybody starting in deep space astrophotography. but get it before you start buying equpiment.

[jgs001]

Steve, another vote for Making Every Photon Count, well worth it. Books - Making Every Photon Count - Steve Richards

Then, I'd suggest looking at an HEQ5 or EQ6, and something like the ED80. It's comparatively small and lightweight, but that only makes the very tough challenge of imaging easier. It's not ideal for the moon and planets, but that never stopped me ... (when you combine it with a £10 webcam...)

[Zakalwe]

Steve can I recommend a book its called "making every photo count" it may save you buying the wrong stuff its available from our sponsor and is very useful to anybody starting in deep space astrophotography. but get it before you start buying equpiment.

^^This^^

My copy arrived on New Year's Eve. It's an excellent read, and should be mandatory reading for anyone new to this game:icon_salut:

[MGSteve]

Cheers I'll get a copy of that book.

The thing that puts me off webcams is their low picture quality. I'm a bit of a sucker for DSLRs & the quality of the images

What's the difference between taking multiple pics with the DSLR vs video with the Web cam? You can stack them both, can't you?

Surely the DSLR way is better as the resolution is many times better?

[jgs001]

You can, but the frame rate of the webcam will help overcome atmospheric seeing conditions, and staking 500 of 2000 frames is quite easy... I'm not sure I'd want to try shooting 2000 frames with an SLR... You also have to take into account the crop factor, the webcam is about 8.5x, so you get in much closer. If you try an SLR with the 1.6x crop factor (compared with 35mm that is) then the FOV for Jupiter will, give you a small dot... at 1200mm you can just about get some band detail showing... if you try really hard.

[MGSteve]

You can, but the frame rate of the webcam will help overcome atmospheric seeing conditions, and staking 500 of 2000 frames is quite easy... I'm not sure I'd want to try shooting 2000 frames with an SLR... You also have to take into account the crop factor, the webcam is about 8.5x, so you get in much closer. If you try an SLR with the 1.6x crop factor (compared with 35mm that is) then the FOV for Jupiter will, give you a small dot... at 1200mm you can just about get some band detail showing... if you try really hard.

Ah, ok - that makes sense. No, I wouldn't like to take 2000 frames with the DSLR either, lol

[Zakalwe]

You can, but the frame rate of the webcam will help overcome atmospheric seeing conditions, and staking 500 of 2000 frames is quite easy... I'm not sure I'd want to try shooting 2000 frames with an SLR... You also have to take into account the crop factor, the webcam is about 8.5x, so you get in much closer. If you try an SLR with the 1.6x crop factor (compared with 35mm that is) then the FOV for Jupiter will, give you a small dot... at 1200mm you can just about get some band detail showing... if you try really hard.

As an example, here's an image of Jupiter. This was taken with a Canon 50D mounted on my Nexstar 8"GPS. You can see how little of the frame it occupies. Webcamming is the way to go for planetary work.

(click for bigger image). The original file is nowhere near as grainy (that's the image getting compressed so I can get it onto Photobucket- a 50D creates 16mb RAW file sizes). The original still is lacking in a lot of detail....multiple webcam frames would bring some of that out.

[jgs001]

And this one was taken with a Philips SPC900... I can't remember all the details, but it was 570 of 1204 (I don't know why) frames...

[themos]

Webcams and DSLRs have pretty much the same size pixels. Planets are tiny (arcseconds in size). You might think that you can up the focal length so that the planet takes up most of the DSLR sensor but we're not in space and the atmosphere limits the useful image scale to about an arcsecond per pixel for long-exposure photography, maybe 1/10 of that for planetary (which relies on stacking hundreds of frames). Pushing image scale further just gets you more noise from the atmosphere.

Jupiter, the largest (apparent) planet is about 46 arcseconds so 500 pixels should be about the limit imposed by the atmosphere. If you use a DSLR, you will be wasting almost all the megapixels as they will be recording black sky. A 640x480 webcam would just about do it (cover Jupiter) and it will give you that fabulous fast frame rate ( from 5fps to 30 or 60fps, and 8-bit to 16-bit, depending how much you pay) you need to collect many frames quickly.

Why do you need many frames for planetary? Stacking frames (combining them in software on a computer) is a great way of increasing Signal-to-Noise ratio which means smooth, detailed images. We would do it with faint deep sky objects (DSO) if we could afford the exposure time, too! But a planet can saturate a pixel in a fraction of a second whereas a DSO will take minutes to do that.

Furthermore, it turns out that among those many frames, there will be a lot where the atmosphere just happens to play ball and not distort the image too much. Such conditions are fleeting, lasting under a second, so they are not a factor in DSO exposures, which just have to average it out. But with planetary imaging, we can just ask software to find these good frames and only stack them, making our final image as good as is theoretically possible with our setup.

[MGSteve]

Thanks for the advice, I've had a good read of the book and it all sounds great so far. I've upgraded the 400 to 50D (low noise performance was a good reason) and will be getting the camera's IR filter modded as well.

For the mean time I'll get a cheaper eq 3.2 mount and just use the camera. I've got a pretty good 250mm zoom which will do for playing around with. I'd love a SkyWatcher Explorer 200P scope, with an EQ5 mount, but once you add on the motor cost its over £400, which is a bit much at the moment. LOL, saying that I blew £460 on the camera. At least the sale of the 400 will recoup a bit of that outlay.

The camera should be enough to get me started anyway

Anyone got any suggestions of how to mount the camera to the EQ 3.2 mount ? There don't seem to be any off-the-shelf adapter kits.

I'm an IT geek, as such DIY stuff is a bit out of my comfort zone!