Midnight_lightning

1 minute ago, Scoobs767 said:

Just had a go at turning one of them, and I must admit I was stunned as how easy it was to lift the dolly leg until the wheel was off the ground.  No effort involved at all. They seem to be designed with good mechanical advantage.

They should be easy to rotate and lift, I was wondering more about whether they might flex laterally in a breeze, that sort of thing.

31 minutes ago, Scoobs767 said:

You mean the screws at the end of the dolly legs that lift it off the wheels? 

Yes. 

6 hours ago, Scoobs767 said:

Hello.  I have the Orion Atlas tripod and the Celestron AVX tripod which I think are the same dimensions as the EQ6R Pro tripod (which I think itself is the same tripod as used for the AZ-EQ6),  but have check on all this.  For these tripods, the toe-to-toe distance without the legs extended (but fully spread) is 33 inches and the height to the base plate is 28 inches.  I have just bought a manufactured dolly ("wheeley bars") for my Atlas. It was quite expensive but solidly built (see ASTOptics wheeley bars, but there are others out there too).  Due to the leg extension knobs being on the inside of the tripod, they butted against an adjustment knob on the wheeley bar, so I had to extend the wheeley bar legs slightly to fit them, and also had to extend the tripod legs by a few inches too.   The final fit however is good. The final extra height is just 5 inches compared to if the tripod was seated on the ground and unextended, and the the additional leg spread might be good for stability.  I've not taken the set up outside yet, but from testing everything indoors, the mobility looks good and the dolly is sturdy.  

Thanks, that is really useful.

Do you think the threaded stand-off legs on the dolly will be rigid enough for imaging? 

If I go down the dolly route I was thinking maybe not use these and just lift each side an put a brick underneath?

I currently have an HEQ5 and Esprit 80 left set up and carry it out for each session.

As you say the 120 and EQ6 would be to heavy to lift so I am thinking leave it set up and wheel it out - I only go 10 feet over a hard surface. 

Since posting I'm now thinking have 3x 3 wheeled "coasters" - put one under each tripod leg - wheel it out and lift each leg individually to remove coaster once in position.

13 minutes ago, gorann said:

That suggest that you are really running near the limits of your mount - maybe that would not be a problem with a bigger mount. Also, I still do not really understand how rotating the filter wheel could change the balance. You do not change the weight on each side of the center of gravity of your telescope. If that was the case - would you not be in trouble after a meridean flip?

The mounts fine, its me wanting perfect balance. Since I had the stellar tune done the mount rotates very freely - with the clutch off you could gently spin the RA and it will just keep spinning for quite a while. 

When balancing it with the EFW anywhere other than vertically up of down (home position) I can only get balance on one side of the pier or the other. So balance it one side and I can let go in any position and it just stays. Move to the other side and its not balanced. Took me a while to work it out but its because the CoG isn't symmetrical without the EFW vertical - it only affects Dec balance.

I'm sure the mount could handle the mis-balance, before the tuning I wouldn't have even being able to detect it due to stiction, but I put so much time, effort and money into this hobby I am looking to get the best out of everything  

12 minutes ago, gorann said:

PS. APM even sells it with a Riccardi as a set:

That's interesting  

15 minutes ago, gorann said:

But I am not sure why you need that camera rotator.

If I rotate from the focuser for framing the weight of the filter wheel being offset from vertical throws the mount out of balance. 

I suspect I'm also going to have an issue with the FW or Lodestar (they stick out on opposite sides) colliding with the mount when used with the 120.  I may be able to reduce the risk by adjusting the orientation - but again throwing the balance out - choices!

If I could just rotate the camera it would be easier to frame targets and allow better balance. 

8 minutes ago, gorann said:

This is what a simply stretched image showing what it looks like when I use a 52.5 mm distance between reducer (TSRED379) and chip, and it is the best I got so far. I also include the finally processed one where I used a few tricks in PS to kind of fix the stars.

Nice image, the PS tricks worked well

Unfortunately, I need 60mm back focus + the width of an adapter and with no dedicated reducer I'm wondering if the Esprit 120 is going to do the job. 

20 minutes ago, gorann said:

Unfortunately SW does not make dedicated reducers for the Esprits (those for the Evostars do not work for Esprits), and the ones that people have got to work are two from TS (TSRED379, TSAPORED075) and the Riccardi reducer. With the TS reducers you need only one adapter ring while you need a whole costly bunch for the Riccardi. I have a TSRED379 and after much testing with distances I kind of got it to work with my Esprits, but for an APS-C ship I still get some annoying star elongation and chromatic abberation in the corners. It may be that with the newer and slightly more expensive TSAPORED075 you could get better results. It may also be that you need to be lucky with the particular sample you get.

I assumed that if you got good focus using a mask that the backfocus must be ok. From what you are saying it sounds like you also need to adjust backfocus within the "in-focus" range. Is that correct? 

Presumably you are talking fine adjustment with Delrin spacers  or similar?

21 minutes ago, Laurin Dave said:

Skywatcher do a pillar mount on wheels which will get around this potential issue

I looked at the SW pillar mount last year, for a different reason but got warned off by a few people who reckoned the tripod was a much firmer base.

Always hard to know with these things without trying or getting good references.

16 minutes ago, Laurin Dave said:

I'd think the EQ6R-Pro would be ok or its Ioptron or Avalon equivalent, are you setting up each time?  If so you don't want something too heavy or fiddly to balance.  

 

I leave the rig set up but have to move it outside each session. I'm thinking of having 3 x 3 wheels "coasters", one under each leg so I can wheel it out and then one leg at a time remove the coasters. Also looking at full dolly's but they are expensive and its something else to wobble

19 minutes ago, Laurin Dave said:

The 120 has loads of room for backfocus 90mm or so, it comes with a spacer to which you need to add 55mm,  my setup required a rather expensive spacer ..  also were you aware that SX have just brought out a new FW with inbuilt OAG which gives 55mm backfocus .. 

I think the backfocus issue comes from the flattener used, the straight SW flattener gives 75mm which is fine.

I haven't identified a reducer yet, seen people discuss Riccardi, Hotech etc but the ones I looked at so far only have 55mm BF so looks like they are aimed at DSLR users. 

22 minutes ago, gorann said:

Not sure why you worry about seeing. Since you say that you have your current mount guiding at 0.21" RMS, which is almost unbelievably good, that must mean that you have very good seeing at you location (that kind of super guiding would be impossible with even slightly bad seeing), so an Esprit 120 would have no problems catching more details than an Esprit 80 if you have it on a mount that can handle it, like one of the EQ6 varieties.

Just trying to understand where the limitations are.

For example if the guiding isn't limited by the seeing it may be worth me buying a Stellar Tuned EQ6 from the outset rather than an out of the factory one and then maybe later wanting to get it tuned? 

I need to check that RMS figure, I'm sure that's what I was seeing but it does sound too good.

1 hour ago, Laurin Dave said:

I have two ES Reid checked Esprits from FLO a 100 and a 150.. both are great so would recommend an Esprit 120 ..    but, good as it is with 0.8"RMS guiding I think you'll need a bigger mount than your HEQ5 to do it (or indeed an Esprit100) justice (an EQ6 equivalent or better).  When I first got the 150 I ran it on a Stellartuned AZEQ6 

Based on the 100 and 150 do you think the 120 will go on an EQ6R-Pro without crashing the tripod legs - just read a post that suggested this combination may prevent meridian flips and zenith imaging?

I would be interested to know which camera you used for these images? 

7 minutes ago, andrew s said:

This is well worth repeating.  Regards Andrew 

The thing is (aargh!) the HEQ5 limitation severely restricted the scopes I could use - now I'm considering an EQ6 I have even more options  

That said I do think the Esprit 120 would be good, I'm so pleased with my 80. As I mentioned above, the only issue with the 80 was the short back focus on the flattener so I'm trying to see if its the same with the 120. I would REALLY like a manual camera rotator in the image chain but no chance with the 80. I know you can rotate from the focuser but it changes the balance and unless the FW was vertically up or down it would never balance the same on both sides of the pier. I notice it more since the Stellar tune as the mount now rotates so freely the slightest misbalance is noticeable.

2 minutes ago, andrew s said:

The diffraction limit it is just under 1 arc sec for a 120mm objective a d about 1.5 for 80mm.  

Stretching my knowledge now but does that mean if the scopes diffraction limit is less than the seeing limit - as in 1.5" is less than 2" seeing - the seeing dictates what is possible and the scope doesn't have any influence. I will probably also use a reducer so if the diffraction limit is based on focal length it would be less than 1.5" at say 600mm (840mm native)?

1 minute ago, andrew s said:

The same is of course true for the optics. Very few locations and or nights can deliver diffraction  limited seeing for a 4 or 5" scope.

So much to consider  

So, is seeing going to have a much bigger impact with a 120 than an 80 - is it the aperture or focal length that influences it?

Just wondering because the reason I am looking to upgrade is to get more detail in my images (and allow me to get smaller targets).

My pixel scale with existing SX814 and 120 would be 0.91"/px which I think is ok for 2"-4"FWHM seeing.

32 minutes ago, Laurin Dave said:

I have two ES Reid checked Esprits from FLO a 100 and a 150.. both are great so would recommend an Esprit 120 ..    but, good as it is with 0.8"RMS guiding I think you'll need a bigger mount than your HEQ5 to do it (or indeed an Esprit100) justice (an EQ6 equivalent or better).  When I first got the 150 I ran it on a Stellartuned AZEQ6 in an observatory and had guiding of 0.5" RMS (albeit only achieved with 1" guide exposures).  I now have it on a Mesu with guiding of 0.4" RMS and the stars are much tighter, in fact on resolution the Esprit 100 on the Mesu is as good as the Esprit150 on the AZEQ6..   The point I'm making (or trying to make) is beware of investing in the optics without a mount capable of exploiting them as you'll loose field of view for no increase in resolution..  

I am as we speak looking more closely at an Esprit 120 and EQ6R-Pro set up

I haven't looked at mounts recently, does this mount seem like a reasonable  way forwards - just looked at Mesu and they are out of my price range?

From what Olly was saying I'm now thinking the mount doesn't need to be perfect, just better than the seeing.

For info, I would like to continue using EQMOD, PHD2 and SG Pro.    

EDIT - Do you use a reducer on your Esprits, I cant see a dedicated one for the 120, just a flattener? The only issue I have with my esprit is getting back focus - my EFW/OAG/CCD takes 60mm.

Thinking of getting one of these mounts but not sure it will fit in my HEQ5 cabinet.

Does anyone have dimensions, ideally the ranges for the spread of the legs and height.

Also, does anyone use a dolly with one of these - I wouldn't be able to lift it once the scope is mounted.

3 minutes ago, old_eyes said:

I did a quick check with PHD2 Log Viewer. For those sections 8-11 it gave RA RMS from 0.55" (0.12px) to 0.68" (0.15px) and Dec RMS from 0.43" (0.10px) to 0.54" (0.12px). PA error around 1.5 arcmin. So no, you haven't got px and arcsec mixed up (a mistake I have sadly made several times). The header says that the  guidescope FL is 400mm and the pixel scale on the guide camera 4.43 arcsec/px. That's another setup error I have made before now.

Thanks for checking it. I'm pretty sure that when I was actually imaging it was showing an RMS of 0.21, I took a screen shot at the time but cant find it - also it may not have been the same night as this log. I use OAG with Lodestar so the guide scope is the esprit. The Dec drift is beyond my understanding, I generally do 20 min exposures for NB without problem, this was just a test when I got the mount back, it's not run in yet so may settle down.

23 minutes ago, gorann said:

Have a look at these on Pete's Astrobin:

There are some very nice images there and generally star shapes are great - although oddly some of them show quite a bit of star stretching in the corners with an ASI1600 - presumably more so if it were full frame. I'm being picky though, I would be please to be imaging at that standard  

2 hours ago, ollypenrice said:

If you want the best and largest flat field in your approximate budget, with the best controlled stars, buy a used TEC140 with dedicated TEC flattener. You'll also get an FT focuser and the best QC in the business into the bargain. Mine produces tighter stars, especially bright blue ones, than either of the Tak FSQ106 scopes I use here. Indeed much tighter. This is confirmed by a second TEC140 I also use here.

Let me be honest: I put the optics last in the imaging priority list. For me it's mount, camera, optics without any doubt whatever. Now you clearly have a supernaturally good HEQ5 if it's pulling an RMS of about  0.2. arcsecs. You cannot bank on that continuing with a heavier scope and and one with a longer moment. Nor can you bank on your outstanding HEQ5 marching on forever, so you might want to leave some budget for a mount upgrade. Be aware that you're leading a charmed life with that mount! 😁 My Mesus run at around 0.3 arcsecs but they've been doing so for years.

But what would I buy without pushing your initial parameters? An Esprit 120 from FLO.

Olly

Thanks Olly, great advice as always.

I'll take a look at the TEC 140 but where do you pick these things up, I've been looking on SGL and Astro Buy Sell for various scopes fro a while and not seen much?

I can be slow on the uptake   but your "supernaturally good" comment alerted me to a high probability of a cock-up on my part 😮. TBH I'm still at the stage where I know what to do but don't always understand "why" in detail - including guiding so "mia culpa". I thought I had the RMS set to arc" but I'm wondering if I was looking at pixels - sample log attached (see entries 8 through 11 - everything else was calibration and Guide Assistant).  I would be grateful if you would take a look and let me know what you think. Whilst imaging it was showing around 0.21 RMS but I suspect dithering must throw this out (?). The HEQ5 has just come back from Stellar tuning so this is a first run, its not run in yet but hopefully will improve and should last quite a while - I think all the bearings have been replaced. Compared with pre-tuning its massively improved, I can leave it to run for hours whereas before I would be constantly tweaking it.

Thanks again Olly.

PHD2_GuideLog_2020-04-11_203434.txt

2 hours ago, Skipper Billy said:

You do!  I have noticed that after I changed my budget scope for the Takahashi I do a LOT less in Pixinsight! 

You have a very nice scope there Skipper - and lots of great images

13 minutes ago, Skipper Billy said:

Its also worth bearing in mind that a skilled processor would turn out images form a budget scope on a budget mount with a budget camera and filters made from sweetie wrappers that would wipe the floor with my efforts from a reasonably specced outfit!

That's a good point and something I was conscious of while reviewing images on Astrobin. Whilst a lot can be done in processing, and I am currently spending a lot of time learning PI (a benefit of the lockdown!), I still want the best raw ingredients I can produce

12 minutes ago, pete_l said:

 

Maybe have a look at what you drive and then buy the telescope that "that sort of person" would buy 😛

Interesting idea but I buy a car for comfort. 

For astro equipment its all about the quality of the image, I dont care what it looks like or who's name is in it 😛

Just wondering if the issues I have seen in the images I have been reviewing are as much to do with how those setups were calibrated as the quality of scopes.  I guess  a lot of people, myself included, are not experts when it comes to tuning sets ups, adjusting tilt etc.

3 minutes ago, Skipper Billy said:

But you said ......

 

Would you be looking at every sub and be thinking would it have been better with a Tak??

Just playing devils advocate! 😉 

Pretty much. I will look at each sub and say, could it be better? What could I do to make it better? But I will also ask was it worth the extra £? 

My budget was around £2500 to start with, I then started looking at the TSA-120 and APM 115 LZOS (around double when the extras are included) expecting to see a significant improvement in image quality. I haven't costed a 106Q but I'm guessing it will be at least £6.5k with a flattener adapters - I could just buy it but if I survive longer than I'm expecting I might have no where to live :0

 Also, I'm really looking for a longer FL - be interesting to see some full frame images with stars as good as yours taken with a TSA-120.