xboxdevil

Hi Can I take the 21cm dovetail if it's still available? Thanks Steve

Hi Graham It’s not ideal but if you have a Barlow lens you could try attaching that first and then try adding the camera afterwards and you might get enough focus. Good luck Steve

Started 5 mins ago on BB2....looks interesting.

I think a lot of us on here have been through this quandary at one time or another and it's a really difficult one. In part because there are so many options and in part because you are unsure which option is going to best suit your preference. Over time your preferences may evolve too so this can be a bit of a moving target. You will also find that your mood and energy levels may also play a part any given time. For me the main the considerations are usually along the lines of: What targets I want to look at (or maybe image in your case) Ease of set up for what I want to achieve ......Yours might be different of course. If I’m tired and don’t want to faff then I’ll go for a DOB, just take it outside and wait for it to cool down. You might need to tweak the collimation but you can practice this beforehand. If you don’t know your way around the sky then the moon and brighter planets are still very easy to find but you’ll need to plan a bit to find other targets (can be both frustrating and rewarding). Many people on this forum have managed some very decent planetary images with the right camera and software. Next easiest setup for me would be the Alt/Az GOTO mount with scope eg skymax 127. I have a cpc800 which is a bit bigger but will likely be a similar setup - slightly more setup needed to level mount and do a star alignment and you’ll need power but targets are easily found via the keypad menu, so less planning / time spent finding objects. Planetary imaging will be easier albeit with less resolution (linearly proportional to diameter) and I’ve seen some good attempts at smaller DSO imaging. The hardest setup for me is an EQ mount plus scope - I find it a bit more fiddly putting it together and polar aligning but it’s all relative and probably not that hard when you’ve done it a few times. Very capable setup that will give the best DSO imaging capability. Best bet would be to go and visit someone locally and see what’s involved with any setup and what the view is like through the eyepiece, might be worth a shout out to see if anyone is nearby. Good luck with whatever you decide and don’t forget to check out the for sale section here and astrobuysell as you can get more kit for your money when it’s been lovingly looked after by someone else first. Steve

I was pleased with this, although although taking pictures afocally with a DOB mount and a phone camera is a bit like threading a needle with a pair of gloves on!! I nudged the scope so that the object of interest would be just out of view then carefully tried to move the phone so that it was in the right place - One minute you see the white dot that you are aiming for but more often than not just as you are about to click on the screen the phone camera adjusts focus and you can’t see a thing!! This time I was lucky and managed to take the picture just as Copernicus had drifted into view. The things we do to amuse ourselves! The main crater is Copernicus, 93km wide, 3.8km deep. Scope: Orion Optics 1/10 PV 250mm F6.3 on DOB mount. Eyepiece: 2" 9mm Explore Scientific 100°. Phone: Lenovo Phab 2 Pro. Original image Afocal Phone snap@ 175x taken 23/05/2018 22:42. Cropped version was sharpened in Gimp then contrast and shadows were improved using standard iPad image editing tools. Thanks Steve.

Here are a couple of links that might be useful: http://garyseronik.com/a-beginners-guide-to-collimation/

Pm incoming!

Great technical write up to go with the image, not being an imager I can’t say that I understand it all but at some point I might!!

Thanks for sharing!

Well that was a bit trickier than I expected! I struggled against the wind bouncing the DOB, the alt axis dropping a bit and 3 Security lights from nearby houses, anyway got there in the end. I wouldn’t be so sure about the accuracy but it’s as good as I could get in the night. Star used: Betelgeuse (maybe needs additional declination correction?) Drift Times (s): 36.24, 36.31, 36.39 - last reading was better placed across the field of view than the first couple so will use that rather than the average given that you’d expect the highest value to transverse more of the field of view. 36.39/4= 9.0975’ True field Magnification = Afov / True field = 40/9.0975X60=264 x mag. approx. Not sure if I’ve done that right though?

Superb thanks, I didn’t even think about measuring the transit time, what a great idea. I’ll report back with an answer......(at some point)

Hi Does anyone know the exact magnification that I would have with the following configuration: Revelation bino viewers 25mm volcano top ortho’s Celestron 2x Barlow 16” Meade Lightbridge (focal length 1829mm) First time using this combination and I was absolutely blown away by the detail on the moon. Any help appreciated!!

Very nice!

Thanks, some great comments, any thoughts from any cpc925 owners?

Thanks for the replies and info. Yes, I still have those scopes but haven't used them in years, I always found the EQ6 hard work (although the views from the 10" OO scope were very special) and the big DOB was a pain to drag out. Yes, mainly visual but still interested in some webcam imaging. I'd be interested to know any more differences in respect of the views because that would be the primary reason to upgrade. I'm also interested in cool down times too. The dew bit sounds like a pain too but I guess everything is manageable.