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astrophotography....


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In short, I have a SW Explorer 130p and a Nikon D60. If I get a T-ring, can I do astrophotography?

I've heard a lot about people not getting focus, but some can with a barlow etc. Is there a clear and definite answer on this? Am I wasting my time pursuing astrophotgraphy with this scope? :) I'm not really into the idea of modifying it, but if it works only with a barlow, this isn't the end of the world! At least it works!

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I'm not an imager but reading the posts on this forum, I would would say no.

You can put your camera on a normal tripod and take a widefield picture of the sky. However, because the camera is not moving at the same rate as the stars, if the exposure is too long the stars will appear as arced trails.

If you were to attach a webcam to a barlow and film through your scope, then you could take short videos of the moon or planets, collect all those frames into a pile, reject the bad ones and stack the good frames together to make one composite image. Video is useful in taking a huge number of frames very quickly to counter the effects of the atmosphere that will blur any attempt to create an image.

The above examples can be used when there is no motor attached to the mount in order to track accurately. You don't mention what mount you have but if it is the one that came with the scope and is fitted with an RA motor, I am sure that although good enough to track objects when observing them, it wont be accurate enough to track a deep sky object for long enough to get the number of exposures that you need. You need a good strong mount with the correct polar alignment which will help secure the tracking accuracy that in turn will help provide you with enough time to secure those exposures.

I would only get a T mount if I already ahve a good motorised mount. If you don't have this, then I would use the camera to take just wide field shots or use a video to do planets and the moon.

James

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Panzer I have just started doing some astrophotography and a T mount is a useful thing fitted onto the barlow lens. You can also attach your camera to the scope without a barlow but need the ring adapter for the camera to be attached to the eyepiece holder which is screwed into the focuser. You should be able to get good lunar and planetary pictures and I have also had reasonable images from M45, M42 M31 via the camera. Dont expect "Hubble like" images.

Neil

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Thanks for the replies. I have a synscan goto mount. Would this help with the problem of tracking dsos? Neil, so basically I can do astrophotography by just buying a t ring, but the images wont exactly be competition worthy? Im not that bothered if the images aren't as spectacular as one would hope, but if it looks equal/better to what is viewable through the eyepiece, I'd be happy. Is it worth buying a t ring or a webcam?

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You can certainly photograph the Moon (And the Sun with a suitable filter) using your scope and camera. Long exposure photo's using the mounts drive will also be possible but they would be quite a challenge. You could try setting up to take, say, 30 second exposures - lots of them! - and stacking the "acceptable" ones in Deep Sky Stacker (freeware!). You may only get around 20-30% "acceptable" BUT this will allow you to achieve your aim. To process the stacked images you will need a piece of software like Photoshop (which can be prohibitivle expensive!) or GIMP (which is free) - not quite as good but suitable for a beginner.

I nearly forgot - You will need "Darks" as well - just take photo's (about 25 of them) of the SAME exposure length as your "images" but this time with the lens cap on! These can be loaded into DSS with your "images" (properly called "Lights" by the way) and will help. Then onwards and upwards into the black art of astrophotography!!

For around £20 you can buy "Every Photon Counts" by Steve Richards (get it from FLO - see logo at the top of the page) - this will guide you through the first steps of astro photography an tell you what to do as well as what NOT to do!! It will certainly save you its cost in no time by showing you how to avoid expensive mistakes!!

Edited by Bizibilder
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Ok, lets take it in simple steps.

For Astrophotography you really need to be able to track the stars apparent motion across the sky to enable long exposure and reveal greater detail in DSO's for example. (A very simplistic explanation)

At the other end a non tracking mount can equally be used for shooting the moon and planets. To shoot the moon you could attach your DSLR, or you could get a webcam and record avi's to stack (this can also be done for planetary imaging.)

I think the issue you will have with your scope is not enough inward travel to achieve focus. This can be resolved by using a barlow.

To connect to your scope you will need a T Adapter for your camera:

Adaptors - T Rings

The T Adaper will attach to your camera and would will then need something like this to connect your T Adapter to your scope:

Adaptors - FLO 1.25-inch T mount camera adapter

This will allow you to connect your camera to your scope and get you going.

Im a little concerned about the term 'competition worthy' - what exactly do you mean? Some of the images displayed on here are taken with several thousand pounds worth of equipment, some are not and are equally as good. That isn't to say you wouldn't get some decent images with your set up. As you get more and more into AP you will see that there are other factors that come into play. For example there is a whole different discussion on guiding with astrophotography.

I hope the above makes some sort of sense?

EDIT: What Bizibilder said as well!!!

Edited by Digz
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Extension tube makes the lack of in-focus even worse. You need a shorter focuser, or you can use a Barlow (which changes the optics so that the in-focus is less of an issue, but increase the F ratio and "ruins" deep space astrophotography).

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Wow some quality replies there! Thanks all!

Digz - thanks for posting those links, I wasn't quite sure exactly what was needed in order to get started, didnt know there was another adaptor needed to mount the t-ring to the scope!

When I mentioned 'competition worthy', I was merely explaining that I know not to expect any kind of professional or jaw-dropping results with this scope/mount/camera, so presumably I will be less fussy with the final results than what a pro would be. Basically, as long as I can get clear photos of what I can see with my eyepiece, but hopefully improve the light gathering with the benefit of DSLR long exposures, I'd be more than happy!

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Your welcome :)

Its nice to see that your expectations are not set very high in relation to your scope. Many a time there are people who want to get the kind of images seen in magazines and become very disappointed when they cant with their 'beginner' kit.

For me the key is perseverance, practice, practice and more practice. Dont be afraid to ask lots of questions either, there are many people on this site who are keen to share their knowledge and learnings.

Good luck as I look forward to seeing your first astro images :(

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I think I'll drop £30 or so toward FLO when payday comes on those adaptors. If I can't get wide field views of DSO's because I'm forced to Barlow it, Oh well. I would probably most like to photo that faraway stuff but I suppose you can't win 'em all! As long as the moon/planets look equal to what is seen through EPs, I'd be more than happy.

Regarding expectations, yeah, I've heard a few people expected to see scenes from Star Wars (including sound effects) through starter scopes and then completely give up when they are met with nothing but humble, greyscale dots and smudges. I show people Andromeda, and an edge-on galaxy I found under/near Ursa Major (its NGC number I have forgotten, dammit!), they just turn back at me with a kind of "Is that it?" look on their faces.

I try to explain its not what you can see, but what you can see that's impressive. A grey smear only visible out of the corner of your eye is possibly the furthest, most massive thing your eye has, and ever will see!

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You're better off with a cheap webcam for the planets - they will be very small on your dSLR even with a Barlow.

Would the detail still be there on a 12 megapixel if I zoomed in on the actual photo taken? I've heard people say a lot of bad stuff about cheap webcams, bad pixelation etc

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If youre going to persue AP, then the scope is not the only thing you should be thinking about at the moment. I started with a Nikon D60 too, and theyre a bit of a pig to use for astro. Great for normal daytiime use though.

Firstly you need to get around the problem of remote shutter activation as in bulb mode, the control software (Nikon camera control pro - via USB) wont go past 30 seconds on a D60, so you have to time it manually. This problem was solved by modding an IR remote shutter release control (taped it to the camera and wired a doorbell up to activate it... ding dong!).

Second is the quality of the output: I found that a D60 heats up real quick, so high ISO/long exposure subs are out. In addition the colour is nowhere near what is should be.

Use the D60 to learn for now, but at some point you will have to swap it for a Canon 1000d. Seriously, it will make your photos a billion times better than anything from the D60. I had the same choice at first (Nikon or Canon), and I chose Nikon..... DOH!!! But back then, i had no idea id be sticking it on a telescope :hello2:

Edited by Uranium235
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Not wanting to disagree with Uranium (:hello2: - there is some good advice there), nor wanting to start a debate about which is better, but you can get some decent shots with Nikons :hello2:

Having said that it is well recognised that Canons are better for AP. This was manifest in the dedicated astro camera they brought out the 20Da.

I currently use a Nikon and am pleased with what I get, however at some point I will want to move to a dedicated CCD so I can take advantage of narrowband capture etc.

As Uranium said, learn with the D60 for now and see how you get on. If you find AP is for you then you can consider swaping to a Cannon :hello2:

Edited by Digz
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Heh :hello2: not to worry, I wasnt going into a Nikon V Canon debate. But its just the D60 that was the issue. When compared to other cameras in the Nikon range, there were a few important options missing, and the battery would only last about an hour.... and if youve only got one battery, then its "session over" pretty quickly :hello2:

Spare batteries, thats another essential item come to think of it.

Oh, just remembered another thing... no live view on the D60! Focusing will be a royal pain in the backside.

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lol no worries, the statement was more aimed at what I was about to say sparking some Nikon v Canon debate which wouldn't help the OP :hello2:

I must say the ampglow on my D200 is horrendous!!!

Yep spare batteries are essential otherwise its a very short session - oh and keep an eye on them. Many times I have left my camera on a 600s exposure only to come back out and find the battery has died 2min into the exposure - d'oh.

I must admit I'd love to benefit from live view :hello2:

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Hi Panzer, from another beginner in astrophotography - I say why not give it a go.

However, it very quickly struck my how hard this all is. But nothing worth anything is ever easy.

You may want to look at the web cam route.

I have a Canon 7D, which I bought mid last year for 'normal' photographs & I love my camera.

However a good CCD webcam can do more & so much better. I bought this Cheap Pre Flashed SPC880 CCD webcam bundle - 47842 - discounts & offers= pictures are better than the camera.

Saying that, i've only been able to use once so far ............

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Hi Panzer - There's a lot of very good advice here, but I noted that you've got a 130P... I started with a 130P, although mine was on an EQ2+RA drive - I see you've mentioned you have a synscan goto, so you're obviously able to track in RA and DEC which is an excellent start :hello2:. The mount should allow you (with good polar alignment) to get anything between 30-90s exposures without star trails.

HOWEVER, when I tried mounting my 300D to the SW130P, I had a REAL problem bringing it to focus - There was insufficient in-focus :hello2:. I think I remember calling FLO at the time and mentioning what I was trying to do and them advising that it IS feasible to move the primary mirror closer to the secondary (a hacksaw job that sounded way too much of a potentially catastrophic mod to me :hello2:!) but also the focuser isn't really made to carry the weight of a DSLR... That 130P was bought about 3-4 years ago though, so they may have changed the design since then(?), but I would suggest calling one of the guys at FLO to talk it through with them before you buy anything...

Re planetary imaging on the 130P though (especially moon but also Saturn / Jupiter), you'll find that you really can't go to far wrong with the cheap SPC880/flashed 900 bundle Scarlet's mentioned - Even though you're talking c. 1.3Mb vs 12Mb, you'll find that the web cam will almost certainly give you better results than your DSLR as the stacking process (c. 1000+ frames shot at c. 10fps) will average out the frames and address the majority of "seeing" issues.

Of course it does require you to have a laptop outside but free apps are available for capture / stacking / mosaics (like WXastrocapture, Craterlet, Registax, Avistack, MS ICE, Imerge etc) but as the "off the shelf" web cam is very limited with regards to long time exposures, it's really not ideal for trying to capture images of any DSO unless it has a a pretty high magnitude (unless you have it LX modded). However, you can certainly get some (relatively cheap) fun out of it and capture some images that you can certainly show to others that they can't easily see down the eyepiece...

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Ah thanks guys, really appreciating all the helpful replies. So if I buy the webcam Scarlet mentioned, will I still have the in-focus problems dslrs have? How would I rectify that to get clear images?

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Ah thanks guys, really appreciating all the helpful replies. So if I buy the webcam Scarlet mentioned, will I still have the in-focus problems dslrs have? How would I rectify that to get clear images?

It didn't solve the problem - I still have to use the 2 x barlow lense.

Which is a pain in the *** when looking at the moon. Nice close sections - but a bit too close sometimes :hello2:

It may be worth seeing if there is someone local to you, to borrow one for a testing session ??

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I agree with Scarlet... and if you can borrow a barlow for a night or two then that would be great....

However, lunar images with a barlowed SPC 880/900 webcam can be pretty impressive if you take enough frames/AVI - I've found it's a good idea to watch the screen and make some "rate 1" adjustments as the AVI's are running through. Personally I use 10fps as any less you may start getting "seeing shimmer" and any more you either risk the frames being compressed or frames being dropped as the bus on the laptop can't cope... The exposure rate is usually somewhere around 1/250 and then you can play with the gain.

You can even try some barlowed mosaics - Frustrating as hell if you miss a few slots (have a look at JGS01 sticky in processing tips using imerge) but when it comes off, they're really pretty impressive... and HUGE!

Capturing Jupiter / Saturn can be tricky - I'm certainly no expert, and the attached were taken with a C100ED Refractor (FL 900mm @ f9, as opposed to your 650mm / f5 which will give you less FOV), but hopefully it'll give you an idea of the sort of thing that's possible. All of these were barlowed, Nos 1 and 3 of the lunar shots are mosaics (No 3 you'll note has a pane missing at 5pm), and No 2 is a single pane. Just for reference, I've read that the Phillips web cam gives a similar view to that of a 6mm eyepiece (and obviously barlowed is c. 3mm)

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