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jetstream

Poll:Exit pupils for DSO's

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So I'm curious what exit pupil range is used for DSO's by experienced "hunters",in Dobs,Refractors and Cassegrains.What range do you have,what are your goto exits and what do you find yourself using the most.This is just to have another way of looking at eyepieces.I realize what exit pupil simply does-increase or decrease magnification.Then there is the contrast issue.This may prove interesting.........ANY TAKERS?

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I do not consider myself experienced, but generally I use an exit pupil of around 2mm or so. The 11mm ES82 probably the most used eyepiece on DSOs on all my scopes and quite often I will use only this and 24mm ES68. Note that I have a coma corrector for the Newtonians, which is 1.1x.

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In all the assortment of scopes I have ever used and looked through, the exit pupil has never been a consideration and has never been given a thought.

Really don't care very much, may be simple but if I can see whatever well and comfortably I don't really care. If the scope and say 12mm BST give a good view and a "wrong" exit pupil you can stop your viewing, but I will continue.

Be honest do you go out and calculate each exit pupil before you use an eyepiece ?

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Depending on the target object, between 2-4mm works for me.

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Its so dependent on mag needed for each object, but hunting, my favourite two eyepieces in the 10" give 7.3 and 5.4mm then once found and if mag is needed , I find it most comfortable to maintain above 1.6mm , to be honest though I don't consider it when choosing the eyepiece, mag and field are more important.

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I vary wildly, from 5-6mm for really wide-field objects, through 3.1mm using the 31T5 on the C8, for searching and fairly wide objects, all the way to 1mm, or even 0.7mm on small planetaries. On galaxies I use 2.2 and 1.7mm most often, but occasionally I go to 1.2mm. Much depends on conditions as well. Under dark skies, the larger exit pupils work better

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The exit pupils I use vary widely from 5.8mm (Nagler 31mm + 12" F/5.3 dobsonan) to 1mm or even less (6mm Ethos + 4.7" ED refractor). I have some light pollution to contend with so often it's more productive to start with a smaller exit pupil, which is where the Explore Scientific 20mm / 100 degree eyepiece comes in handy.

Effective exit pupils can vary when filters are used as well. Basically, it's good to have a range of options !

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2-5mm for me, sweet spot somewhere around 3mm for my eyes. In my 250px and 350p this is the 14mm ES 82. i wrote a review of how good this eyepiece is for DSO in the 250px. It gives 85x in the 250px with a 3mm exit pupil. It gives a 117x in my 350p with a 3mm exit pupil. I haven't given the 350p a serious run yet (as it's still box fresh) but a preliminary run thorugh all my eyepieces (to ensure they all come to focus which they do) indicated that the 14mm will still be a winner.

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From the back yard,rule of thumb normally 3- 1.5mm,I find larger exit pupils don't work so well unless you have a dark site.This being for galaxys/nebula, star clusters more tolerant as regards exit pupil.

Experiment & see what works best in your locale.

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