Laurin Dave

And its free!   I cant see why you 'd lose any detail on your target Andy   ..  your image scale will be 0.8arcsecpp but you'll be seeing/mount limited any way

Dave

I'd just use your 268 and crop your images if needed, however you'll often find (as I do with my Esprit150 and APSH chip ) that there are numerous smaller and not so small galaxies in the fov which give interest and context, also there are various galaxy groupings where the native 268's fov of view would work very well... eg Markarians Chain and neighbours .. Leo Triplet ..  M81 M82 and neighbours 

I bought some Televues to go with my Meade 10" LX200...  I was chasing fov .   They're very nice but gave no meaningful increase in fov above the 1.25" 62deg 24mm Meade eyepieces/0.63 reducer combo I already had. 

Dave

I believe that your fov will be limited by the telescope field stop to 46/2350 x57.3deg ie to 1.12deg and that no eyepiece/reducer combo will exceed this ..   It can be quite an expensive lesson to learn as I found out !

Dave

Well done Steve that's looking good and I'm pleased that your enthusiasm has been re-kindled.    For those with Pixinsight there is a new Photometric Mosaic Script (available in the latest release) which has been developed by fellow Basingstoke Astronomical Society member John Murphy.  On the examples that have so far been tested it has given excellent results and is worth investigating although by necessity it is most definitely not one click.  

Dave

Fabulous image Richard, and I shall have a look at the link

thanks

Dave

Excellent talk @tomato Steve, thoroughly enjoyable and informative

Dave

Very nice Adam, I'd suggest a fair bit of RGB and L on the Horsehead, Flame and the various reflection nebula in the region NGC2023, IC432 etc ...   hopefully just one frame with the Tak  ..  for the rest there's always next year by which time the pier extension will be ready ! 

Dave

ps your Epsilon180/2600 will frame that nicely

2 minutes ago, DaveS said:

More information on the Astrograph site Here. Though I'm now a little confused as to the back focus.

I'd suggest that the diagrams indicate that if you want to use with a Canon or Nikon camera lens get the short back focus version..   they both have setups for 55m

16 minutes ago, Fellside said:

Hi

I almost sure you need the "GEM auto Flip Go To" ticked in Sitech. The mount should track passed the meridian up to your 2 degree limit. Or it will be flipped by NINA within that time.

I may be wrong, give it a try.

Graham

I have that ticked ... (used with SGPro)..  so it may be that

A real Christmas Cracker!   beautiful ..  Merry Christmas 

Dave

32 minutes ago, tooth_dr said:

Ok, thanks.  I'm using 2x2 binning, 8 seconds on luminance and 15 narrowband.  Perhaps this is too long for the scope 180mm/F2.8

Hi Adam I use 2x2 with 3/15 at f7 and 3/10 at f5.5 so I would try reducing the exposure for your faster system .. (although I’d thought SGPro rejects saturated stars)  and also reduce the step size, you could increase the number of points just in case..  also do you know the relationship between your critical focus zone and step size in micron ..  I’d imagine there’s some guidance on this somewhere in the ether..  

Dave

Taken last night after watching the conjunction.  A couple of panels with my new Askar200/ASI2600mc combo, 1.5 hrs per panel with a large overlap over IC405 and IC410, enhanced with some higher res Ha and RGB (over the Flaming Star)..  Spacing/tilt still to be fixed and more practice needed with focus..  resampled at 50 % as its huge!

Seriously impressed with both the camera and the lens..

Thanks for looking 

Dave

8 hours ago, ollypenrice said:

There is another option for Dec, by the way. You can put the full payload on the kitchen table with a length of thin tubing (or a pencil...) under the dovetail and find the point of balance. Just be sure the pivot is square to the dovetail. Mark this mid point and put it at the centre point of the saddle plate.

I've never bothered but I did use this method on a review mount I once had.

Olly

I did that in both directions for my side by side by side rig... I used a workmate though and some masking tape to mark the balance points ... it worked a treat..  Mesu's seem very tolerant of balance

Congratulations , just seen this image in Astronomy Now together with a write up by @ollypenrice extolling the virtues of colour CMOS ..   if I hadn't just bought one and seen what they can do I think  I'd need a lie down!

Dave

4 minutes ago, gorann said:

Ah, you are like me - getting into the buying mode when clouds settle in for too long

Indeed .. gives us something to do..  hopefully get some clear skies soon 

2 minutes ago, gorann said:

Nice images and good star shapes Dave!

But a bit qurious why you whent for the Askar 200 f/4 from Sharpstar instead of the well proven and less expensive Samyang 135 f/2 with more aperture (twice the lightgrasp)?

I’ve already got one.  All part of the plan 

I've found that they usually do, but just drop them a line to make sure  ..  

Very nice...  I got my ASI2600MC, its been out to play once and I'm very impressed with it

Dave

It is always very dangerous browsing on FLOs website at this time of year with so many tempting offers on display, I did this on Monday 7th December and before I knew it an Askar 200 f4 lens and ASI2600MC were on order.  The camera was quoted as out of stock with a lead time of 15-20 working days but to my surprise both turned up on Saturday morning together with FLO's seasonal warning of snow, even more surprising was that for the first time in weeks a clear sky was forecast that evening.   The new system was quickly attached to the mount using a vixen saddle which I screwed to the piece of wood between my scopes that carries all the cables (actually a piece teak from my school physics lab bench where my dad was the handicraft teacher) and darks and flats were taken.   At nightfall the lens was quickly focused using a Bhatinov mask and the coarse and fine focusing rings.   My main target for the evening was going to be a mosaic of IC348 and NGC1333 in Perseus but in the hour or so before they rose high enough I went for the area around the Fireworks Galaxy.  In total I got 1 hour on the Fireworks, 2.5 hrs on IC348 and 1,5 hrs on NGC1333 before the clouds rolled in.

Processing was relatively straightforwad although when debayered the 150subs took up 45GB, the darks look very good with and very CCD like with as promised no amp glow, the flats were flat, very little vignetting and no dust bunnies.  

The results are below.... (I've added my hi-res Fireworks galaxy to the first image).   There are some spacing and tilt issues to work through but overall I'm very pleased with the results for such short integrations times, particularly with the richness of colour  that the camera picks up in the dust which I always struggle with on my mono setups.   Even more so since these are from Bortle4/5.

Thanks for looking

Dave

The Fireworks Galaxyand Barnard 150

IC348 and NGC1333 in Perseus

The new scope between its bigger brothers..

9 minutes ago, gilesco said:

The initial result I've got from the 120 tell me that backfocus is just spot on with the FLO supplied adapter for CMOS cameras.

I had heard about the manual errors, back focus worries before purchase etc ... but FLO supplied everything to make it work! No extra stuff needed, will probably post an instance of my first image, from a single bad seeing session shortly.

Excellent. Looking forward to seeing it .  as I’m sure you’ve got, it’s 55mm from the m48 thread , also at f7 pretty forgiving and with a smallish  sensor (Sony694 size) I’m told by a ‘man who knows’ that you can dispense with the flattener 

13 hours ago, gilesco said:

I am not trying to change how far back my sensor is.

Perhaps this (it is an exaggerated scale) will make it more clear. When the tube is extended further there is more sag (upper image of focuser tube and draw tube):

If the tube achieves focus without being as extended as much (lower image) there is less sag.

Of course the lower image means the camera is closer, and so spacers are required to the right of the drawtube to compensate for that distance.

In any case, as others have noted- and this is an exaggerated scale, the Esprit focuser is a very snug fit and others don't expect this issue. But if you had a cheaper not so snug focuser, it would be an issue.

Hi..  It’s not quite like that as the focuser bearings are a fixed length     and so support the same length of drawtube regardless of how far it is extended 

Dave

1 hour ago, Hogarth said:

I have a Esprit 100 and my draw tube is also quite far out to achieve focus.

also whilst researching back focus on the esprit range , it seems widely accepted the manual is incorrect, well certainly for the 100. The manual says for mine 63mm of back focus when using a FF, but it’s actually 55mm.  I tried mine at 63 and at 55 to test and it’s certainly way better focus at 55mm

not saying the 120mm manual is wrong, but I would investigate this just to confirm.

 

 

its both 63 and 55 mm ..   the flattener has an 8mm spacer/ adapter attached that reduces the thread from M66 to M48..   on the 150 there’s a somewhat longer M62 to M48 spacer .(I think the 120 is the same as the 150)    So for the 100 it’s 63mm if your using the M66 thread and 55mm if using the  M48 thread ..  

Astro Pixel Processor will do this and has a 30 day free trail 

I'm sure it'll be fine, I have an Esprit150 and ASI1600/EFWOAG etc, the drawtube needs to be a long way out to focus but I have never had any tilt issues with this setup and the stock focuser.   The only advantage an extension tube will give is that there'll be 2" or so (length of the extension tube) extra of drawtube on the scope side of the focuser bearings to possibly add a small bit of counterbalance to the weight of the camera etc.   The camera will still be exactly the same distance from the focuser bearings.