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Hi All - I'm fortunate to have a EQ6R Pro that has been in residence for about a year (unfortunately predominately hidden in garage due to weather and forest fire conditions for most of the year). The few times I've had it out, I've failed to get a proper Polar Alignment. I've used all the tools Sharp Cap, PoleMaster, Plate Solving and so on.
My main issue has been once I'm within a couple of degree's I can get it to position no better. Fine adjustments on both RA and DEC give cause to jump around. I've watch every video/help show and finally have to admit defeat (hopefully short lived).
The EQ6R Pro has the same issues the EQ6 has (with northern latitudes). RA adjustments are just as horrendous no matter how sensitive I try to be.
The EQ6 had some tools created for it that one could purchase (RAIL Kit) that seemed to solve one of my issues (unfortunately not available for the Pro).
My question is: Has anyone else experienced this and if so how have you addressed it. I'm at that place where I'm thinking on replacing this mount if I can't resolve it and the next step is quite more expensive.
Hi guys I have a few questions
I've recently upgraded to an ASI533mc pro from a DSLR. As I am living in the southern hemisphere and in bortle 6 light pollution, I don't have site of Sigma octanis to get a rough initial polar alignment and previously found that using the reticle feature on my DSLR live view with the synscan polar alignment routine, I could get quite accurate polar alignment in 5-10 minutes (180second unguided subs with around 80% keepers, I don't trust the estimates but under 2 arcminutes generally) My initial setup is usually 3 or 4 degrees out in azimuth.
I had a go with phd2 PA last night without much luck, I'm assuming because my initial setup was more than a couple of degrees out. I'm happy to just use the synscan routine as I can complete it quickly enough and achieve a good enough alignment, especially now that I'm guiding, and it would seem I would have to run a few iterations of it anyway to get my initial setup close to simulate you lucky northerners with your bright polaris in the polar scope. So my question is, what is a decent piece of software with reticle live view to use with my Asi533mc pro? I currently have NINA, ASI studio and PHD2 installed and I couldn't figure out how to superimpose a reticle last night.
Also, Sharpcap pro seems to be the most commonly recommended software for polar alignment. However I am using an SCT telescope and a smaller sensor camera so my field of view doesn't meet the requirements stated by sharpcap. Has anybody tried using Sharpcap pro PA at 1500mm and 945mm (f6.3 reducer) with any success?
Besides drift alignment, which would take longer than the synscan routine for me, are there any other pieces of software that I should try that won't cost an arm and a leg?
I'm running an HEQ 5 with a Celestron 6se using an Asi533mc pro imaging cam with an ASI290mm mini on a ZWO OAG for guiding.
I'm open to suggestions for other software to use for imaging, I only installed NINA because the functionality and price point is amazing, and it gets rave reviews.
Thanks in advance wonderful people!
No questions but thought my experience with PA using Sharpcap and a Canon 800D might be of help to some.
Although I thought I was nailing Polar Alignment with a polar scope on my Fornax Lightrack, I could not get longer subs than 150secs. I considered buying a Polemaster but I thought was a bit pricey, so looked at a small guide scope and a webcam solution with Sharpcap which was a good bit cheaper.
Researching Sharpcap and DSLRs, I read that PA might be possible with my WO ZS73 (430mm) main scope. I needed to install the ASCOM platform and then the DSLR Camera Setup for Ascom and, of course, Sharpcap. Sharpcap recognised my 800D camera and I completed an "Excellent" PA within minutes. On the first night I managed 180sec subs and experimented with 240sec - all nice round stars. How far can I go? I had done a manual PA first which was a fair bit off from the Sharpcap PA, so not as nailed on as I thought!
I'd rather not be using a laptop but I can't argue against the results.
I hope that might be useful for some.
It is long time I wondered whether the mount polar scope could be used in a less tiring, but more effective way to achieve a convenient, very quick and fairly precise polar alignment (till better as 1 arcminute), than could be achieved usually, and without having to buy rather expensive devices made for this purpose.
The solution I found – easily achievable and doable for the most of Astro DIYers - is to mount a small video camera attached to the polar scope eyepiece. This will allow us to achieve an excellent alignment to the celestial pole.
I invented the acronym VAPA (Video Assisted Polar Alignment) to define my mount stationing method.
NCP on January, 2018 NCP on May, 2021 (Stellarium)
In addition to the Polaris, there are two stars of mag 6.5 just around the North Pole celestial field, in Ursa Minor constellation.
They are λ (lambda) and HIP 7283 (double star)
As you can see the position of two stars is very interesting, in fact their RA position differs by a value very close to 135°. In addition, it is possible to see in the same field two other fainter stars whose positions are very peculiar too.
If you draw a line from each tiny star to meet the NCP, you will see that these two lines define a right angle having its vertex at the NCP. (see pics below)
I made this modification on my standard HEQ5 (old black 'Heavy Duty' one), but the same arrangement can be applied to any other mount that has a polar scope with removable eyepiece and sliding ring with glass reticle.
Considering that the HEQ5 has a very small polar scope (its objective lens has a diameter of about 14 mm), the system will work even better on other mount models, equipped with polar scopes of much larger aperture.
Polar camera construction
- 1 IMX 225 (or IMX322) module with 6mm lens, equipped with Video out, OSD and power supply cables (from Aliexpress)
- 1 OSD menu pcb (optional)
- 1 small plastic box
- 1 film plastic can (135)
- 1 rca panel connector
- 1 coaxial power connector (3.5 mm)
- coaxial cable (conductor plus shield)
- some 2mm screws, spacers and bolts
- 1 epoxy resin
The small polar camera looks as you can see from the pictures below
Making the Reticle
Materials (see photos below):
an A4 paper sheet on which we have printed a circle graduated in degrees
0.030 mm (30 micron) fishing wire
3 small truncated-cone springs
- Unscrew the eyepiece and remove the three adjusting grubs of the reticle ring.
- Remove the reticle ring and unscrew the threaded flange which holds the glass reticle in place
- Remove the glass and reposition the flange.
- Attach the ring to the centre of the graduated circle with a very small amount of vinyl glue (flange down)
- Stretch (gently!) a piece of wire and fix its ends tightly (with small pieces of scotch tape) at 0° and 180°, in order to precisely bisect the circle and the ring.
- Do the same thing with another piece of wire, stretching it between 45° and 225°.
- Make sure that the two wires cross in the centre of the ring accurately (although extreme precision is not required). See photo below
- Using a very small amount of cyanocrilate, solder the four wire ends on the ring, just where they get each other into contact.
- Allow to dry.
At the end of this procedure we will have created a wire reticle delimiting two couples of angles, 45° and 135° wide respectively.
- From the inside of the eyepiece barrel, do insert the tiny truncated cone springs into the three grub threads, the smaller base pointing outwards from the barrel.
- Replace the ring in its place with the reticle towards the polar scope objective.
- Screw in the grubs until the ring is secured, but do not tighten them (see photos below)
Calibrating the reticle
- Adjust the eyepiece so that the reticle can get focused (use glasses if you wear them to see well at a distance!) then fix it with a drop of silicone just on the visible part of eyepiece thread.
- Unscrew the locking ring of the polar scope tube and adjust the distance between the reticle and the objective so that you can see a distant object (a bright star, or a detail on the roof of a building) well focused together with the reticle.
- Fix the tube ring.
If there are one or more grubs around the locking ring, they must be screwed in tightly.
Displaying the area of the celestial pole
- 1 7" 1024x600 HDMI screen
- 1 RCA -> HDMI video converter
- Connection cables
Insert the camera nose (135 film barrel) on the polar scope eyepiece and aim the polar axis at the sky area just around the Polaris
If all the connections are correct, we will see the Polaris on the screen (if we don't see it right away, we can easily find it by searching near around) together with a good number of other stars.
In a Bortle 6-7 sky (as it happens in many suburban areas) we can easily find out stars up to 10th magnitude (provided the atmosphere is transparent enough). The field of view will be about 3°x 5° (see photo).
Camera configuration by OSD menu
The camera menu will get elicitaded pressing central button and you can do your choices pushing up, down, left and right buttons
Fill in the follow parameter:
Push central button to enter Main menu. Push down button to enter submenus and right or Left one to select voice:
- Lens → Manual
- Exposure → Shutter → 15-20
→ AGC → 6
→ Brightness 1
→ Return → Main menu
- Day/night → B / W → Return → Main menu
- NR → High → Return → Main menu
- Special → Defect
- live DPC → On → AGC level 50-60
→ Level 0
- White DPC → On → -level 0
→ AGC 5-7
→ Sense-Up 30
→ Start → Follow indications
→ Return → Return → Return → Save & end.
Leave all other voices at default position
Notice: DPC is the dead (hot) pixel control
Video assisted reticle alignment
This is done by grubs provided just for this task.
Truncated cone springs make the operation very easy and confortable. As you find Polaris in your screen, put it at the center of crosshair.
Rotating the polar axis, you can see the star will move from its initial position, so, you should screw the three grubs in and out until Polaris will stay ever at the crosshair center in any direction you can rotate the polar axis.
Grubs should be secured, but they should no be tighted.
Video assisted Polar alignment procedure
By adjustement of Alt-Az knobs, you should:
1) put the reticle center on the right angle vertex (NCP position on current date) made by tracing two virtual lines, starting from the two faintest stars, as indicated in previous image.
If you are very accurate, you can reach the NCP within a maximum error of 1 arcminute.
2) rotate the polar axis till the two brighter stars get both hidden by two crossed hairs of reticle (the pair one crossing until each other at 135°). If it doesn’t happen, it mean your mount is too
much far from NCP, so you must repeat the step 1).
Note: performing step 2) doesn’t be mandatory, but it will enhance alignment precision.
Photos above are recorded by SharpCap (stacking), thus they don’t display the correct image aspect ratio (12:7) as you can see visually, watching your ‘on the mount’ lcd screen.
In fact, SharpCap do not change aspect ratio (720x576 lines for PAL system) of native analog image captured by a video grabber (Easy Cap or similia).
That is why the above image appears a bit higher as it should be. Obviously, you can align your mount with your notebook screen rather as with lcd display on the mount.
To do that, you must use a video grabber device and OBS Studio to record movies or snap shot.
OBS Studio is a big free software allowing make all necessary image adjustement to reach the correct aspect ratio.
Below I posted an OBS Studio clip (sorry for the big amount of dinamic noise due the sudden ‘défaillance’ of my chinese video grabber … )
2021-05-07 22-41-02.mp4 Beppe