what scope/lens for widefield astrophotography??

[janoskiss]

I want to get started in astrophotography. I want to start with widefield, but not 28mm camera wide, more like several degrees wide. Would like some advice on scope/lens choice.

Scopes I'm considering are:

1) 66mm f/7 WO apo, which would go down to an f/5.6 with focal reducer / field flattener.
2) Takahashi FS-60C, 60mm f/5.9 apo, f/4.4 with focal reducer

These are both a bit over a $1k, and I definitely would not want to spend more than $1500 on scope+reducer+/flattener. I know next to nothing about camera lenses but are there any within this price range that would be a good alternative to a small scope?

I'm in no rush, and still need to settle on a camera - not to mention raise funds :whistle:. It will probably be a DSLR of some sort. I really want a scope that is fast and has top optical performance so I don't have to worry about that part of the equation (field curvature, coma, ...). 80mm aperture max.

:thanks:

[iceman]

Wow! Never thought I'd read that sentence.. although I'll really fall of my chair if Geoff says it :)

What are you going to mount it on?

[Striker]

I dont know how the 60mm or 66mm will go with a DSLR..there fine for small chip ccds but not sure if it will illuminate DSLR chip.

The WO only comes with a 1.6" focuser.
Not sure on the Tak but I cant see it being any bigger.

[janoskiss]

One thing at a time Mike. :lol:
... but I'll start with my existing EQ mount - no one knows what it is; it's Japanese, about 12 y.o., and a lot sturdier than my old EQ5.

[jase]

A 200 or 300mm fast lens (F/2.5-F/3.5) is great for wide field work. Just attach the DSLR, no focal reducers or flatners required. Its the most basic form. You could perhaps use a zoom lens, though would suggest avoiding these. Fixed focal lengths are the way to go.
I would suggest you consider the mount and how you intend to guide. Once biten by the astrophotography bug, you'll want to use a longer focal length or different camera. A good mount will see you through your astrophotography journey.

[janoskiss]

Any out there for under $1500 that won't give me awful aberrations, false colour, coma, etc?

[h0ughy]

yep the one i just bought, and Rocket boy made me do it too i might add, he twisted my arm , I was writhing in pain but in the end i RELENTED.

I bought the Canon 200mm f2.8 L series 2 lens;) :whistle: new about $1100, second hand - i got mine for a tad over $800

[janoskiss]

Thanks Houghy.

Another Qn. Can any of the older film camera lenses be used with DSLRs?

[h0ughy]

depends of the type, generally yes, sometimes with an adapter. Also depends on the manufacturer:whistle:

[janoskiss]

There are just so many types of lenses mounts and cameras it's mindboggling.

How about Pentax? I'm reading that their DSLRs take many of their old film camera lenses as well as some 3rd party lenses... :confuse3:

[ving]

wheres our steve!!! i want our steve back!!! :P

[leon]

Yes Steve The Pentax DSLR dose take all the older type K Mount Lenses, i had a Pentax ist D, and used all the older style lenses, have a cupboard full of them.

They, the older style fixed focus lenses are superb on film cameras but are a bit iffy on the Digital Camera's. lots of chromatic abberation.

I sold mine and went to Canon, superb Lenses, and Camera's, a top lens is the EF 135mm F/2.0 L, if you got one of those and than added the 1.4 extender you would have basically two great Canon Lenses, one at 135mm and one at nearly 200mm.

Cheers Leon

[jase]

Nowadays, you can just about mount anything to anything (if that makes sense!). I have a friend with a Canon EOS 1Ds that uses Nikon lenses. Its just incredible. http://www.cameraquest.com/adaptnew.htm has plenty of adapters.

Just another note on the wide field set up you maybe thinking of - don't forget that many DSLRs have a magnification (1.6 multipler) http://www.luminous-landscape.com/tutorials/understanding-series/dslr-mag.shtml explains this well. If you intend going really wide i.e. fish eye, then you'll need to take this into consideration.

[Geoff45]

If it can be mounted on the camera, it can be used. The problem comes if you try to go the other way, ie to mount a dslr lens on a film camera. This is because the cmos sensor is smaller than a 35mm film frame and a lens designed for the small chip may not cover a 35mm frame. However, I don't imagine anyone will want to do this.

[janoskiss]

Hope you're right. Putting the cart before the horse, I just bought a Canon FD 200mm f/2.8 lens off ebay. Cheap, just under $100. Now I just need a camera that will take it. :lol:

[Dennis]

Steve

I purchased the Pentax *ist DS DSLR a couple of years ago as I had a swag of old K mount lenses, going back to 1976 and they work in manual mode. I love Pentax gear but if you are seriously going to get into DSLR astrophotography, you should buy Canon of Nikon.

Most of the 3rd party accessories and software for DSLR astrophotography provide functionality for Canon and Nikon models, NONE for Pentax.

If you want to operate your camera from a PC, focus via the PC, expose several frames at intervals from a PC, etc. then applications like DSLRfocus and ImagesPlus all cater for Canon and Nikon gear.

I am occasionally frustrated by this lack of support and restricted mode of operation. Using Pentax Remote Assistant SW I can program up to 99 x 30 sec exposures via the Notebook, but otherwise software support is very, very limited.

Cheers

Dennis

[acropolite]

Steve, The FD (mount) lens won't fit any of the Canon DSLR's (EFmount) without an adapter. There are adapters available for around $50US (I have one but I can't tell you how well they perform as I haven't tried mine yet). Also the suffix "L" behind the minimum aperture denotes an optically superior lens usually with apochromatic elements.

[janoskiss]

Thanks Phil, yeah I figured it's not so simple. I think this one might be going straight back on ebay. I don't expect the lenses in those adapters are too great.

[Starkler]

You havent seen my Mercury transit and sunspot pics have you Mike? :P

I was with Dave last night and he spent most of it playing with a laptop and a DSI :rolleyes:

[ashley.gale]

I have a Pentax*ist DL and a 300mm lense, but not a good mount... Does anyone know of a good cheap mount that I can use for my camera? :help:

[Harb]

If you really want cheap, go for a mount adaptor from your camera brand to M42 screw mount lenses......
They are a dime a dozen in may focal lenghts etc.
They will have to be used manually, but that presents no real problem.
you can pick them up anywhere, ie cash convertors or any place like them, camera shops etc.

cheers
John

[CometGuy]

Just a warning about Canon FD lenses, even with an adapter you will not be able to reach infinity. The only way would be to modify the lens mount on the lens.

For the Canon world the 200 f2.8 L has to be the best bang for buck. Great wide open and almost blistering edge to edge at f3.5. Well worth the $950 entry fee. Consider the price jumps to $6K for the 300 2.8 L :(.

Terry