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Focal reducers


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Hi guys

I'm seriously considering getting an atik 314L but on my 200p I'd have an extremely small field of view.

I know a focal reducer would help greatly but that's when it all gets abit confusing for me.

So I'm asking does anybody have any advice or experience that could help me out?

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I can start you off with an excellent article that I snagged from the MallinCam website. Though written around MallinCam video-cameras, the principles outlined are the same for all brands:

http://www.mallincam.net/uploads/2/6/9/1/26913006/focal_reduction_for_dummies.pdf

It would help if you could let us know what telescope & mount you're planning to use. I'm certain more people will be arriving to help you. In the meanwhile, here's another thread on focal-reducers:

http://stargazerslounge.com/topic/251278-sct-63-reducer/

And there are many others you'll find by using the forum search-function. It's to the upper-right from where you're reading this.

Have fun!

Dave

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I wouldn't say the focal reducer will help "greatly" - it will make the FoV greater, but it won't double it. You'd have to check on a field of view calculator online, with and without reducer, to see what impact it has.

It's a small chip, and the reducer won't make it any bigger.

If you want a much bigger field of view:

- get a DSLR

- change your telescope to something with a MUCH shorter focal length of say 500mm or thereabouts

James

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Jambon that's the FOV calculator I used and with the 0.5x focal reducer it seems to give a decent FOV.

I'm currently using an astro modded canon 600D but want something more sensitive and with cooling.

I've been looking into getting an Ed80 but the wife says that's off the cards for a good couple of years yet.

I've also been considering a Qhy8/L but that's only one shot colour and I'm not too sure how much of an improvement, if any, it will be against my DSLR.

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I'm surprised you are fed up with the dslr - what aspects of either using it, and/or the resultant images, makes you want to move to a much smaller cooled ccd chip?

Are you guiding? What sort of exposure lengths are you getting?

Do you get much coma aberration?

A qhy8l is £1000 is it not? Unless i've got the wrong camera in mind.

James

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The results I get from my dslr are alright but I want more detail and less noise.

I also want to be able to mount my dslr to the top of my mount for wide field imaging at the same time.

I'm using a QHY5L-II and orion mini guide scope for guiding and the maximum exposure I'm willing to take is 5 mins. Any more than that and all my images just drown in noise

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I've not knowingly seen any serious DSO imagers use a 0.5x focal reducer. I'd consider starting a new thread about that specific topic in one of the imaging forums rather than the beginners area. I suspect some of the responses will include "get a shorter focal length scope".

Good luck with it all.

James

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