is this An Impossible problem?

[the bishop]

Hi all,

I am what I suppose you’d call a backyard stargazer and have been for a couple of years now, during this time I have just been using my eyes and moving onto a couple of different sized bins. As I decided at the start that I wanted to just try and find my way around the sky before looking at getting a scope, and in general I love it and sorta feel its going ok and perhaps now is the time to jump in and commit myself to getting a scope.

However the problem is I don’t really have a preference of viewing as I like looking at whatever I can, also I’m heavily into photography with a couple of Nikon Dslr’s and so would like to match up the two at some stage, but what to get that is best?? And this is where the headaches come in as I have read reviews and posts and comments that pull me this way and then push me that way, and to make it worse there seems to be “the camp system” just like in photography between Nikon and Canon users... but this time its Refractor is best camp and Reflector inc Dobs is best.

I have looked through various sizes of each type of scope and suffered each owner go on at length how theirs is best one to have, however not one of them has attached a dslr to their scope... but assure me it would be just the ticket!!

Am I asking the impossible question? just what type of scope is best for taking photos with a Dslr?? or is this to wide a request??

And then there is the mount problem... is say for example a sky-watcher EQ5 mount man enough for the job with my very expensive camera bodies

attached to... well at the moment I’m looking at an Evostar 120 or an Explorer 130 or 150 on the said eq5???

either way I understand I will need a motor drive.

Without wanting to have the my camp is best argument will these be good options?? or is there a better option??

Headache notwithstanding

Has anyone out there attached a dslr to either??

What is a good all rounder or is there not one??

Help please if you can

Many thanks

Gra.

[Arushin]

Hi and welcome,

Get a copy of 'Making Every Photon Count' available from FLO. It will explain everything you need to know.

When I first started out I contacted Ian King who is a well respected astrophotographer and he advised me to get a Sky-Watcher ED80 refractor and DSLR...so I did. Brilliant advice in my opinion.

very affordable little APO with excellent optics. I can't see me needing to upgrade for a while yet.

Regards Tony

[rowan46]

welcome bfore you even think of buying try this book

http://www.firstlightoptics.com/books/making-every-photon-count-steve-richards.html

it tells you most of what you need for succeesful and quality deep space photography and more importantly why you need it.

[ronin]

An Evostar 120 will give some CA and in general in astrophotography this is to be avoided.

Additionally it is a bit to long and so any tracking errors will be magnified by the longer focal length.

You relly need to be considering an ED scope to minimise CA or better a triplet.

These are as you will guess a fair bit more costly.

The EQ5 is a possibility with a small scope, thinking WO ZS71 here.

Really the HEQ5 is better.

As you are interested in photography then consider that when you take a picture in day you use say 1/250 sec, in astrophotography you take 10 images of 30 seconds of a moving target and expect (need) the image on the sensor not to move by a pixel if possible. Say this as photography ahd astrophotography are somewhat different. There will be a filter in the camera that blocks some of the wavelengths you want in astrophotography.

Really is a good idea to seperate visual and astrophotography.

[michaelmorris]

To an extent, your choice will depend upon your budget and how portable you want the system to be.

A good compromise might be an HEQ5pro mount with a 150mm to 200mm short focal length Newtonian.

If you want a more portable/cheaper system may be get the EQ5 mount and Newtonian scope and piggy-back the camera with a camera lens on the scope.

I hope this helps

[Fordos Moon]

Point of View from Novice (there are much better experts on here than me):

You MUST read "Make Every Photon Count". I have a Skywatcher 200P dobsonian which I love to bits and will continue to use for viewing and quick sessions between the clouds, but I also wanted to get in to astrophotography albeit as a complete novice. I have just read the book myself and after it (and a lot of advice on here) purchased an ED80 and a HEQ5 synscan mount to use with my Canon 1100d.

I've not got to use it yet but I have every confidence it will allow me to begin the journey into the art of astrophotography.

[nightfisher]

In your position, i would be looking at the EQ5 with R/A drive, and a skywatcher 150 p DS this should meet your visual needs and the scope is designed to use a dslr camera as well

[the bishop]

Hi all,

Wow thanks for the quick replies,

My brother went to a BBC Stargazing Live event this week with his kids and has just phoned me to say that various bods he chatted to during

the evening recommend to him both a book and a scope...

the book “make every photon count” and to consider getting an ED80 or ED100 Apochromatic (unsure of spelling) refractor scope.

This seems to go along so far with some of the thoughts here...

Looks like first port of call is the book...about 20 quid or so....

If I went for the scope... what make? Or is that a stupid thing to ask?? (sorry if it is)

and hey while I’m at it what difference between the 100 and 80 apart from cost...

Also surprisingly he was advised...

why not just get a cheap scope for now and get used to using it and then in the future branch out when

he has a more settled idea of the direction of either planets or dso...

(he’s a good lad he told them my situation as in my post )

a skywatcher explorer 150 was in my sights earlier, but then were several others...

Any more thoughts on the above??

Thanks again

gra

[RikM]

For visual visual use, the ED100 offers more aperture and better views but it is at best f/7.5 when used with a focal reducer. This is on the limit of being too slow for imaging and this is especially important using a DSLR. For imaging, the ED80 can be reduced to f/6.4 so is faster, and has a shorter focal length which means it is more forgiving of tracking errors.

A 150P reflector can give respectable results if the optical train is tickled into alignment. f/5, so faster again and shows no false colour at all. 6" is a good aperture for visual use as well. I am biased, I use one If I had the cash to spare, I would get an ED80 + reducer/flattner with an HEQ5 Pro, and then save for an 8" dobsonian for visual use in parallel.

Count mine as another vote for reading 'Make Every Photon Count' before parting with any cash.

[ollypenrice]

Good summary from Rik above.

The ED80 is better for deep sky imaging than the 100 because it's faster. Fast is important in DS imaging.

But in imaging, number one is the mount. A small refractor will be fine indefinitely on an HEQ5. Put a 200mm reflector on it and and you will want to upgrade sooner or later. Buy below the HEQ5 and you will want to upgrade sooner rather than later.

I image with an assortment of scope designs. Imaging is difficult and it is less difficult with small apochromatic refractors than with anything else. I didn't say better, I just said less difficult. Newtonians are generally faster and cheaper - and better value. But they need to be right.

You asked what is the best scope for imaging and I do have an opinion on that. It's a widefield scope, it's only 85mm, but it is as near to perfect on all counts as I feel I'm ever going to see or use. The Takahashi FSQ85ED. Pity about the price. But you did ask!!

Olly

[E621Keith]

Since the OP is a keen photographer then he must have a good collection of high quality lens. If that's the case than I'd put all the money into the mount and image with his lenses.

Buy a HEQ5 for mount, QHY5 and ST80 for guiding, and a side-by-side bar for mounting the camera lens. Lenses like 85/1.4, 180/2.8, 300/4 and 300/2.8 make amazing images.

[ollypenrice]

Since the OP is a keen photographer then he must have a good collection of high quality lens. If that's the case than I'd put all the money into the mount and image with his lenses.

Buy a HEQ5 for mount, QHY5 and ST80 for guiding, and a side-by-side bar for mounting the camera lens. Lenses like 85/1.4, 180/2.8, 300/4 and 300/2.8 make amazing images.

Good point. And at short focal lengths unguided imaging becomes very possible without losing many of your sub exposures.

Olly

[the bishop]

Hi everyone,

Thanks for the advice.

I think I have deciphered most of the code words and numbers in the posts

And so now have formulated the golden rules...ha ha!! :grin:

Rule number 1 is getting the best most solid mount you can! Over engineered now is an investment in the future.

Rule 2 Astrophotography is mostly fiddly as hell...(but worth it) but taking you down the Digital via CCD mounted cameras

rather than a dslr...(though dslr or web cam is possible for less “in-depth” images shall we say)

Rule 3 read the “make every photon count” book before splashing any cash. £20 now can save a fortune and wasted effort

Rule 4 stargazing and serious AP are really poles apart and use totally different set up and systems

Rule 5* this is most important... don’t whatever tell the wife the cost of a Takahashi FSQ85 Apochromat Refractor OTA

{as its £3,449.00 !! }

Seriously though folks,

thanks everyone for all the advice so far

it has been very informative.

Gra

[Ags]

What is your local light pollution like? I would say you have workable skies if you can see anything of the milky way. Conversely you would have very bad light pollution if you can still see colors in your garden at midnight (tell me about it ). If you have bad light pollution and you can get away to dark skies, and you like the idea of imaging with camrea lenses, you might want to invest in a mobile tracking mount like an astrotrac.

[the bishop]

Hi,

yes I do like the look Astro Trac thanks its worth a consider.

As for LIGHT POLLUTION as I live in a fairly rural area (on the side of a mountain) it was not too much of a problem

at all until last night...when my neighbour tested out his brand new and just fitted two... not one... but two... pir flood lamps

out his back garden, as his dog has become nervous of the dark ??? so its nice and dark then bang 30 sec of light. on and off

So everything is under review as of now... looks like i will have to use the alpha site by the look of it...

Ho hum

[Ajohn]

NoThere are a number of options but I think you can rule out achromatic refractors helps a bit. I have been looking at getting into astro photography for a long long time basically with a dslr. I don't think I have a particular axe to grind but can pass on some bits and pieces from others that I pick and choose a little based on looking through scopes that I have owned. I've had an interest in them from junious school days and used several types on an off over 30 odd years,

The mount gets a bit important. Some reckon photographic weight carrying capacity is often about 1/2 what is quoted but probably don't account for the wind or China.

Tracking what ever you buy for longer exposures seems to be best catered for with an auto guide set up. Some forsake goto and just have that and see it as the most important aspect. In my view it's best to have a mount where that is available rather than a home brew. Alignment also comes into tracking so some form of guidance is likely to be needed in any case. Can be done manually via an off axis guidance gismo. Accuracy of the mount itself can also be improved dramatically with Periodic Error Correction or PEC. Software is used to correct the drive. It's trained manually. There is a need to consider all of this in relationship to exposure time. To give you and idea I took some star shots recently 10 sec at 200iso with a 50mm F2.8 lens. Milky way, 15 of them. I intended to stack them. Problem the exposure isn't sufficient to capture the dimmer stars that can be seen by eye. I will be doing some more so that I can get a hang on this as I don't want to waste money when I take the plunge. I haven't found much useful direct info on exposure time. Scope diameter comes into it as well but not in an entirely straight way.

Worst decision is the scope. As the size goes up the mount needs to as well. I'll rule out Maksutov. I have looked through one of those as they are intended to be. Fairly large and mainly aimed at planetary work and small field sizes. I also bought a small skywatcher one recently for the mount it is on plus curiosity.

Dobs can be guided but as they are on an alt az mount stars still don't remain stationary in the view. The field sort of rotates. That leaves apo's, newtonians and compounds.

Apo's have already been mentioned. The problem here really is vast cost as the size goes up and the probable need for a field flattener for excellent results. There are number of reasons why these perform better size for size than either compounds or newtonians manly in the area of visual use. You can take it as read that a decent 100mm apo will out perform a 6in newtonian on planets in particular but the same problem crops up in other areas. Contrast basically.

Newtonians can cover all needs and allow more size on a cost basis so it's a bit swings and roundabouts versus an apo. I would say these get a lot more interesting at 200mm and over. They come with built in aberrations which effectively means that a coma corrector is a good idea for photography especially at the focal ratios people on here favour. When a 200mm is used with 2in eyepiece fittings and the full field is used the design is such that it looses out on contrast for visual use and it gets a lot more similar to multi purpose compounds or even worse, This gets less of a problem as the size goes up but the angle of view gets smaller. I'm assuming F5 scopes in this. F6 too really. For both photographic and visual use I would favour F6 rather than F5 or shorter as life gets easier for eyepieces what ever the size of scope.

Last come compounds. Schmidt–Cassegrains, Cassegrains and Cassegrainians of various types including Astrographs that are largely aimed at photography.

Schmidt–Cassegrains are jacks of all trades but really need a focal reducer for nebulae etc photography. I've always intended to find out what sensor size they will cover when that is fitted. I feel that the really come into their own at 250mm but the 200mm are useful scopes. They can be bought in decent quality full fork mounts and all sorts of bits and pieces are available for them. For instance piggy back adapters for carrying a camera plus lens or even a small apo. The only problem with the fork mount really is that unlike a german equatorial the scope can't be swapped for another easily. The fork mount gains as it's easy to make the full fork ones rigid at relatively low cost and there is no counter weight as in the other type. All sorts of arguments crop up under this comparison but make no mistake for people who can afford them they are very popular scopes and deservedly so. I would generally go for a Meade. Even though I have just had a problems as a result of buying a Celestron. I have specific reasons for that this time. My 10in is a Meade and I have also previously owned a Celestron.

Next comes the cassigrains such as Vixen do VMC200L and the one that is really an astrograph. The VC200L.. I'm not going to comment much as I have never owned one but they do stand up in comparison with SCT's and size for size are probably better especially the astograph. That isn't clear any more as both Meade and Celestron have just introduced what are primarily astrographs. As a result they are likely to continue making the previous range. I'm assuming Meade are doing the same as Celeston scope wise. I suspect it may go the same way as an earlier attempt to introduce fast SCT's for photography. Great but not much use for anything else. People tend to buy this type of scope for all uses and compactness.

The most common astrographs is the Ritchey–Chrétien. Sometimes just called RC. Never had one and I doubt if I would contemplate buying one other than really keen on just photography and no visual use at all. These concentrate on wide field and photographic efficiency. Most scope spread the light near the edge of the field the RC attempts to concentrate it more. One curious aspect of these is that the ones I know of don't really have the F ratio they should probably because a really fast one would be too expensive to make. There are others. Takahashi do a 180mm F2.8 modified Newtonian that they reckon also works visually. They do other astrographs as well.

I only know of one odd ball. A cassegrain newtonian made by Tak again. This can be used as a very fast astrograph newtonian or at the cassegrain focus. Bit like many of the big telescopes only they usually have other focuses as well. I very nearly did buy one of those. On offer in France at an amazingly low price but the dealer wasn't allowed to sell into the UK and wouldn't no matter how I tried. There scopes were not so well known then and cheaper as a result. When I think I nearly bough a full set of there eyepieces.......

Personally I would look at all scopes but do check that they will cover the sensor size you want to use or an acceptable amount of it. Also remember that smaller scopes tend to cover wider fields. That's parts optics and part design problem. If you really get the bug and want to fit several types of scope including larger ones later an HQEQ6 now will save you money in the long run. Field coverage is just like photography at some point you need to change scopes not lenses. Big buckets catch more photons - actually that is one reason why people buy SCT and as these can come with a good mount they are even more attractive than might 1st appear. Meade have recently introduced a range of APO's as well which might be worth looking at. There is a bit of a message in them. As they get bigger they also get slower - that's how it should be on a budget. I own an older Meade 127mm APO. It's F9 and they also did a 127 at F9. The 127mm has a good reputation. The 127 doesn't. It's always worth bearing that aspect in mind when buying an apo. This is why some are a lot dearer than others. For photography it isn't so important within reason but for visual use it is and does in real terms count for photography as well.

Me I'm trying to downsize. 127mm apo to a 110 that should be photo ok but may not satisfy me visually. A 10in SCT to a lighter weight 9.25in and a mount that makes an eq6 look sick to an old vixen gp dx. I also have a 10in newtonian F4.5 kicking about. I have disposed of several scopes to happy users over the years but often wish I had kept my 8in SCT. For really wide field I may buy a rather cheap small apo with a 6 degree field - and send it back if it doesn't measure up.

http://www.teleskop-express.de/shop/product_info.php/info/p1151_TS-Optics-70mm-F7-ED-Refractor-APO-Telescope---Carbon-Tube---2--Crayford.html

Have to wait until I sell other toys to raise the cash. I generally only buy things that way these days. Not always though.

John

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[Ags]

And I thought _I_ spent too much time thinking about gear :-)

[Ajohn]

LOL That is what happens after buying or even making several forms of telescope - well at least to me. On the other hand it is an area worth some thought especially when some one may not be aware of exactly what they are going to do with it or at what they may want to point it at.

You may notice that no one has replied with the sensor size that a SCT covers with a focal reducer on it.

John

[the bishop]

ummmm i wonder why?

[Ajohn]

Perhaps it's because I had the wrong impression of what had been done to the latest SCT. The Celestron's Edge range is really something. Looks like some of the problems with these scopes have been really fixed and the optics improved rather a lot. Must admit I would have been surprised if they tried the straight fast SCT idea again. Only thing now by the look of it is that it might take the 11in to provide a fast full 35mm frame size image. Not to clear on that point.

John