Hi Leinad
It's been said before the only stupid question is the one that's not asked!
Starting out, I'd use the 40mm eyepiece. I got one for my 8" and found it useful because the field of view was big enough to avoid getting lost. (I actually got it because it gave 30 magnification, the same as my highest magnification binoculars. Well it seemed like a good idea!) In time, you may find the 26mm is sufficient field of view for you starhops?
In this starhop to M104, those asterisms - the isosceles triangle arrowhead pointing the direction to "Stargate", then on in the same direction to "Jaws", then follow where Jaws is pointing to M104 - are so distinctive that you will quickly find yourself centred on M104 or its location. I take the point made that city light pollution may be a problem, but M104 is a bright little fellow, I expect you'll see it in your 40mm, unless your observing location is lit up too much and your eyes poorly dark adapted.
Now I didn't quite understand your question, but swapping eyepieces to observe at higher magnification should not cause any problem. You need:-
1. The OTA stable as you swap eyepieces - so have sufficient friction on the Alt bearings in particular, so that that pulling eyepieces in and out and the change of weight doesn't cause the OTA to swing - up mostly, given you are going to lighter eyepiece through an empty focusser intermediate step. But don't worry if it does - Alt is the easiest adjustment on a dob. Just swing the OTA back down when you have the eyepiece in place and focussed roughly. You'll probably pass over the object easily. (In fact, when I'm on a faint object with faint stars around, and I want to check focus, I often swing the OTA up or down until I find a brighter star, focus on it, then swing back to the target.) You'll also learn to hold the OTA stable with the left hand while you change eyepieces with the right hand (and in complete darkness!
)
2. A rapid change of eyepieces. In this warmer weather eyepieces can stay on the eyepiece rack. I've added a few more racks to my 8" to hold everything I want, within reach. Bottom caps off, top caps on. If I have a 2" in the focusser, I have the 1.25" I want to use next already fitted into the 2"-->1.25" adapter. Let me visualise what I do:- left hand resting on OTA to stop it moving. Object of interest centred in the lower mag eyepiece field of view. Eyepiece cap comes out of right hand pocket to cap the eyepiece - softly so as not to move the OTA. Loosen focusser screw with right hand and lift out eyepiece. If I don't have a spare 2" hole in rack (and I do now
) place eyepiece in left fingers while still preventing OTA from moving with the left hand. Reach down and pick up the adapter holding the 1.25" eyepiece. Fit it into focusser and tighten the screw. Place eyepiece from left hand into rack. Remove cap from 1.25" eyepiece and place in pocket. Done!
3. Rapid focus to quickly see the object. If you have parfocal eyepieces (all are focused at same point on the focusser) - great! But not these GSO ones. So already have memorised how you have to change the focusser for this particular eyepiece swap and quickly adjust to get rough focus. Sometimes the focus point is so different that you wonder what has gone wrong - where has everything gone! But you cannot muck around moving the scope to try and see something. Rack the focusser to where it should be - half a turn in or whatever. Once you can see the object, re-centre it, if the scope has moved or earth rotated too far (you were too slow!), then spend time focussing on it, or the nearest bright enough star, then study and enjoy.
Not sure if that answers your question
Eric
Edit: Oooh? Your question has gone! Here's an answer - we'll let everyone guess the question
