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Joy of long achro scopes.


cotterless45

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Sheer folly on fleabay and I ended up with a Chinese achro 80mm f5. Hmm nice little scope ( thinks )Yikes , the views were terrible, focussing was nightmare and there was so much Coma I thought my eyes had gone funny. Luckily LeeB took it off me off his collection. I'm very interested in the red boy , Altair Astro 152, hopefully I'll get a shot at SGL.

I only use four fracs, from 90mm with 1000mm ota right up to "the yard cannon", 150 f8. After some considerable fettling I have found 127 mm with 1200mm to be just cracking for colour and contrast. Conditions being right , it'll pick up fainter fuzzies.

My favourite is the 102 , just under f10. The colours, contrast and relaxing views are just a joy. Focussing allowance is quite wide. Better control has come by using both hands on the r&p . One each side tweaking until focus snaps. It was the first scope that I ever looked through at PSP and I could go get over the clean crisp views. That's the trouble with star parties , they change your perception. I used to think it was all about aperture ( the emperor's new clothes).

For kick off, there's a variety of testers, getting the "double double",iota Cassiopeiae and currently 36 Andromedae have all served well. For performing from the edge of town on anything from achievable galaxies, nebula and  the tightest of binaries , I think long achros are just ideal. Don't stand on the side of the pool, jump in !

Ckear skies !

Nick.

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My collection is down to two scopes...a 100mm f13 and a 125mm f9. The f13 just punches through indifferent atmospheric conditions and is brilliant for doubles. The 125mm gives noticeably better views of a fair few Messiers - aperture does count in that respect. It also gives a wee bit more colour fringing on the brightest objects too, being that bit shorter in fl, but it doesn't bother me.

There is a distinct 150mm shaped hole in my collection though... .

 

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My 6" F/12 Istar was "joyful" but expensive and hard work to get suitably mounted.

I love looking AT the long focus traditional refractors though :icon_biggrin:

I think 4" F/10 has a lot going for it with achromats. Not too much CA, not too hard to get properly mounted.

Vixen knew what they were doing with the SP102M and TAL with the 100R.

 

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This is not funny. I have set my sites on the 150 V2 red and waiting to get one eye through it at SGL 12. Now reading the above statements it throws a spanner in the works. I'm actually looking for a Frac to compliment my 200 Dob. I Want the frac to give me good DSO's with wide field and also ( yes I know I'm pushing my luck)  some reasonable planet views without too much CA. On top of that I want also to use it for solar. I will also need a mount for the same preferably one that tracks but not heavy enough for astro as I intend to do visual only. So which one ?. This frac is to replace try Skymax 150 as I am struggling with the small FOV.

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On 26 September 2016 at 15:58, cotterless45 said:

Sheer folly on fleabay and I ended up with a Chinese achro 80mm f5. Hmm nice little scope ( thinks )Yikes , the views were terrible, focussing was nightmare and there was so much Coma I thought my eyes had gone funny. Luckily LeeB took it off me off his collection. I'm very interested in the red boy , Altair Astro 152, hopefully I'll get a shot at SGL.

I only use four fracs, from 90mm with 1000mm ota right up to "the yard cannon", 150 f8. After some considerable fettling I have found 127 mm with 1200mm to be just cracking for colour and contrast. Conditions being right , it'll pick up fainter fuzzies.

My favourite is the 102 , just under f10. The colours, contrast and relaxing views are just a joy. Focussing allowance is quite wide. Better control has come by using both hands on the r&p . One each side tweaking until focus snaps. It was the first scope that I ever looked through at PSP and I could go get over the clean crisp views. That's the trouble with star parties , they change your perception. I used to think it was all about aperture ( the emperor's new clothes).

For kick off, there's a variety of testers, getting the "double double",iota Cassiopeiae and currently 36 Andromedae have all served well. For performing from the edge of town on anything from achievable galaxies, nebula and  the tightest of binaries , I think long achros are just ideal. Don't stand on the side of the pool, jump in !

Ckear skies !

Nick.

Shame I'm not going to SGL this Oct so you could have a proper tinker with the 152.  I'm off to the NFL that Sunday.  Also a shame I am not located on your route to Wales or I'd let you borrow it :). If Derek is at SGL he may have his white one to look at.  I phoned Altair and there is no optical difference between the new red and old white.

Glad the 80 f/5 has found a happy home. F/7.5 works superb in this size but it's pretty small in comparison to your lineup!

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Yep, I'll get my eye in a 152.

I think a salient point that folks forget is " what do you want to observe ?" Not only will this narrow down your choices , but reflect your usual observing conditions.

I hope those that get get to SGL will have a good wander around and have a look through scopes which may of may not surprise them . It's one thing seeing these beauties on the web and another in the flesh !

old Nick.

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