5D mark III vs ccd?

[FudgeMaster]

Hi guys!

 

Just starting dipping my toes into astrophotography and am thinking of getting a telescope/mount. 

I currently use my 5D mark III with different lenses, but I'm wondering if there is a really good reason to go for a ccd instead. 

Is my 5D adequate in combination with a telescope and mount. say with an SW explorer - 200pds (HEQ5 pro)?

 

Would love to hear your thoughts on this as I am unsure whether or not to keep using my DSLR.

[Alien 13]

The 5D is best used with camera lenses, not many scopes will cover the large sensor with a flat field so you will get distortion around the edges. Their is no reason not to use the camera and lens combination on an EQ mount.

Alan

[FudgeMaster]

Oh! I didn't know the sensor size creates an issue with telescopes. The lenses I need to do deep sky astro shots are way to expensive. 

So in conclusion I'll have to get a new DSLR body with an APS-C sensor or go for a CCD camera to use the scopes?

[rubecula]

I went the DSLR route, but had the ASI1600 Cool been available then I would probably have gone for that. It might be worth your while taking a look at it.

I'm going to have to wait a while before trying to get approval from my Financial Controller :-)

[wimvb]

FWIW, Maurice Toet produced these with a 5D mark II. You might want to consider a fast scope to go with that camera  Budget allowing, of course

 

[FudgeMaster]

I'll look into the ccd's for a later buy but for now I think i'ts best to stay with the dslr till I get more into it. 

Maurice Toet uses a 5500 dollar scope though:/ A tad bit over my budget:P

Can't I just use a coma corrector and some editing in post to get rid of the distortion and vignetting?

If that's the case I see no better alternative than to go with a reflector and EQ mount.

Especially when having to get approval from MY Financial Controller:P

 

[FudgeMaster]

I was thinking of something in this range.

 

http://www.telescope.com/Orion-10-f39-Newtonian-Astrograph-Reflector-Telescope/p/99602.uts

[hjw]

To be honest I can't see a good reason why not to use your camera since you have it already. Your camera has just over 22 MP - a very expensive CCD has just over 10 MP. You might get some distortion/vignetting in the corners but you can always crop you image. What I would like you to consider instead is a larger mount. The HEQ5 will not handle a 10" scope and will be on its limit with the 8". Sooner or later you want to get into guiding which will add weight to the setup.

Good luck!

HJ

[wimvb]

If you go for a reflector, you should definitely add a coma corrector. Some of the vignetting will be corrected by flats. The rest can be cropped, as already mentioned by @hjw

Good luck

[Owmuchonomy]

Hi. There are very very few scopes that will take advantage of such a large sensor. The number of pixels is also somewhat irrelevant. What is important is the size of the flat field produced by the scope and the sampling in arc seconds per pixel. Have a play with the following webpage.  http://www.12dstring.me.uk/fovcalc.php

[hjw]

2 hours ago, Owmuchonomy said:

Hi. There are very very few scopes that will take advantage of such a large sensor. The number of pixels is also somewhat irrelevant. What is important is the size of the flat field produced by the scope and the sampling in arc seconds per pixel. Have a play with the following webpage.  http://www.12dstring.me.uk/fovcalc.php

I agree, but the pixel size of, for example, an ATIK414EX is 6.45µm and the Canon 5DIII has 6.25µm. That's similar enough to now compare 1.4MP at the cost of 1149 pound at FLO with a 22.3MP camera the OP already has. I would stick with the DSLR, because to get a CCD with similar performance (image size, FOV and resolution wise) requires the donation of both kidneys

Clear skies

HJ

[MartinB]

58 minutes ago, hjw said:

I agree, but the pixel size of, for example, an ATIK414EX is 6.45µm and the Canon 5DIII has 6.25µm. That's similar enough to now compare 1.4MP at the cost of 1149 pound at FLO with a 22.3MP camera the OP already has. I would stick with the DSLR, because to get a CCD with similar performance (image size, FOV and resolution wise) requires the donation of both kidneys

Clear skies

HJ

There's not doubt that you get a lot more chip for your money with a DSLR than a specialised cooled CCD astrocamera.  Mass production sees to that.  You also get a daytime camera of course.  So if £ per pixel is your predominant consideration then it's a no brainer.  However you then need to factor in the £3-4000 you need for a Takahashi FSQ that you will need to cover that nice big chip.  And then when you've got it and you see Saturn, the Ring Nebula, M51 or whatever as a tiny little thing and you decide you need a big crop then you start to see that the worth of an astrocamera is only partially assessed by it's chip size.  

[MartinB]

1 hour ago, hjw said:

I agree, but the pixel size of, for example, an ATIK414EX is 6.45µm and the Canon 5DIII has 6.25µm. That's similar enough to now compare 1.4MP at the cost of 1149 pound at FLO with a 22.3MP camera the OP already has. I would stick with the DSLR, because to get a CCD with similar performance (image size, FOV and resolution wise) requires the donation of both kidneys

Clear skies

HJ

There's not doubt that you get a lot more chip for your money with a DSLR than a specialised cooled CCD astrocamera.  Mass production sees to that.  You also get a daytime camera of course.  So if £ per pixel is your predominant consideration then it's a no brainer.  However you then need to factor in the £3-4000 you need for a Takahashi FSQ that you will need to cover that nice big chip.  And then when you've got it and you see Saturn, the Ring Nebula, M51 or whatever as a tiny little thing and you decide you need a big crop then you start to see that the worth of an astrocamera is only partially assessed by it's chip size.

Having said that, I still think it makes a lot of sense for you to use your DSLR!! 

[FudgeMaster]

Lots of great points here. Seems like I have to research some more before I delve more into this. I am leaning towards using the dslr as I already have it, in combination with a reflector and a good mount. 

 

What mount can handle a 8-10" scope with auto guider, coma corrector etc. ?

[hjw]

The way I understand the original post is: OP has a camera, a nice one at this. He is about "dip his toes in AP" and buy his first imaging scope (SW 200PDS). Can he use his camera on this scope? I would say yes. There will be some artifacts but even if the image is cropped down to APS-C size, the result will be a 10MP image. I do understand that a cooled CCD camera is superior as my pictures become unusable when the exposure time is more than 10 minutes. But this problem only shows up when guiding is used (maybe 2 years down the track). As I mentioned before, I would rather spend this money on a bigger mount - I wish I had. The NEQ6 is not that much more expensive than the HEQ5 but gives you another 5 kg payload. I am now 4 years into AP and I would love a CCD camera but can't justify the expense of camera, filter wheel, narrowband filters etc. for what would be a minor improvement in quality.

[ollypenrice]

Firstly it would be potty to buy a DSLR with a smaller chip when you can use the one you have and simply crop it! The effect would be precisely the same and cropping is free...

If you compare only the pxiel size and the chip size of a CCD and a DSLR you miss the point. The Bayer Matrix on a one shot colour camera of any kind imposes some limitations, most notably on narrowband imaging which beats light pollution and can be done in the moonlight, certainly in Ha. Yes, you can do NB with an OSC camera but the Ha is getting signal from a quarter of the pixels and not much even then unless it's modified. Also the CCD has more well depth for dynamic range.

In any DSLR discussion you'll see links to brilliant and CCD like DSLR images such as those of Maurice Toet. I know his superb images pretty well because he has taken a lot of them here  - but you really mustn't underestimate the effect of F2.8. That is more than three times as fast as the 'no slouch' FSQ106 which will also cover full frame.

So I'm not a great DSLR fan. I don't want to shoot twice as much green as red or blue. That's OK in terrestrial imaging but makes no sense in AP! And if I lived in a lesser climate than SE France I'd want to work on clear moonlit skies. And then there's cooling. I'm sticking my neck out on this thread but I would go for CCD.

Be aware that going below F5 is never easy. There is no easy 'fast' astrograph and there is certainly no easy cheap one. Give me F5 and a CCD and I'm like a pig in muck. 

Olly

[Knight of Clear Skies]

19 hours ago, FudgeMaster said:

Just starting dipping my toes into astrophotography and am thinking of getting a telescope/mount. 

A couple of thoughts, have you considered/budgeted for guiding and have you thought about Ha sensitivity? The IR filter in an unmodded DSLR will block much of the Ha signal.

What's lenses do you already have please? There are some large targets up there that don't require long focal lengths. One approach that might be worth considering would be to invest in a decent mount and image with your current camera and lenses to get you up and running.

[Grierson]

Just a further minor observation from a novice. I have the 5Dmk2 and and it has considerable weight which I would guess will be similar to the Mk3. Not sure what the implications will be attaching it to your proposed reflector but it was a significant issue hanging it on the end of my 80ED refractor.

[Debo]

You should use what you already have and see how it performs before spending more money.

I used a 5D and thought it produced good images, as mentioned you can always crop your images if the edges are not so good.

[ollypenrice]

1 hour ago, Debo said:

You should use what you already have and see how it performs before spending more money.

I used a 5D and thought it produced good images, as mentioned you can always crop your images if the edges are not so good.

OK, and if it performs well you keep it. But what if it doesn't? What has this told you? Above all, what has it told you about CCD? Nothing. That's why I take the view that I do about CCD. It is not a dark art, not a mystery, it is just a very well thought out technology for taking deep sky images under both good and difficult field stuations.

Olly

[mftoet]

As mentioned by others, use your 5D Mark III as you already have it. A mount can never be solid/massive enough for astrophotography, but an HEQ-5 sounds like a good starting point to me (though it's not so future-telescope-proof as the heavier EQ-6). 

You can start using your (tele)lenses to explore the possibilities and experience the difficulties (challenges!) involved in taking a decent astrophoto. 

You don't need a 5500 dollar scope to start with. For the record, it took me 15 years before spending that much money on a telescope. On the other hand, the motto of a friend of mine is: "buy quality, cry once". He's got a point. 

A decent first scope that covers full frame is the Teleskop Service Star 71. You have one for 1200 euros. 

[FudgeMaster]

Thanks again for many great responds!

Iv'e done some astroshots without telescopes and mount, just by stacking different exposures. But these are nothing like the ones you guys take with your scopes.

The milkeyway is almost never visible here in Norway, and I have tried on several occasions to capture it in all its glory. I either have too much light pollution, to thick atmosphere or just not enough of the center to capture a decent shot. This being said I'm a complete noob in astro so there might be ways around this I haven't used yet.

The EQ-6 seems like a good choice for me as I to like to futureproof (within a livable budget) my toys:) 

And the Orion 10" f/3.9 newtonian is both fast, and has a long focal length. 

Maby this is a good starting point?

 

Here are some shots iv'e done without telescope/mount

[StuartJPP]

What lenses do you currently own and use? My very first images were taken with an unmodified Canon 7D and a Canon 70-200mm f/4 lens...both of which I already owned so my initial outlay was pretty low (basically just the 2nd hand AstroTrac). I chose M31 and M45/The Pleiades as my first targets since both will only slightly benefit from a modified camera and they are pretty large and quite bright.

M31 - Andromeda Galaxy (Details by clicking on the image):

M31 - Andromeda Galaxy by Stuart, on Flickr

M45 - The Pleiades (Details by clicking on the image):

M45 - The Pleiades - Widefield - 1920x1200 by Stuart, on Flickr

They aren't award winning images, but I was pretty much over the moon with them, especially after I had learned to process the M31 image better as my first attempt at processing it was quite rubbish.

Targets that are not rich in Ha are best suited for unmodified DSLRs as above but that isn't to say you can't image targets with Ha either, just that you will have to spend more time (a lot more time) gathering the data.

I know some people will say go for a CCD, but unless you can spend a fair chunk of money, personally I'd hold off for a while and see if astrophotography is something that you want to pursue and invest more money in. Get a decent mount as that is something that you will need regardless then add things once you know you want to go further. Spending £800 on a mount (HEQ5 for instance) is palatable but buying a mount, camera, filters, filter wheel etc. can make it prohibitive and you might not even venture deeper into it.

Maurice's advice is sound though, buy once...

Try what you have got and see where the weaknesses are and then buy the best bit of kit you can afford to plug that flaw...that would be my advice.

[FudgeMaster]

I currently only have two lenses. The sigma ART 50 f/1.4 and the kit lens 24-105 f/4. Had a 100-400 f/4-f/5,6 but sold that as I never used it. This was before I got into astro though:/

 

Those shots look amazing. Both done with the 20-200 f/4?

[StuartJPP]

2 minutes ago, FudgeMaster said:

Those shots look amazing. Both done with the 20-200 f/4?

Correct, both were captured with a Canon 70-200mm f/4 L IS lens at 200mm @ f/4 (the 70-200mm f/4 L non-IS lens will be just as good if not slightly better). Note that I didn't choose it for astrophotography as I already owned it.

If I had to choose an OTA specifically for imaging the stars I would probably opt for something like the Star 71 as mentioned. BUT I do like the dual use of lenses, especially for daytime photography as well but they are a compromise.