Do you need to Polar Align for Solar AP?

[kirkster501]

^^^^

...and if so how to do that during the day without an observatory?

Is Solar AP just like regular planetary/lunar with the exception of the filter on the front of the scope?

[ursamajorro]

The aparent movement of the Sun is similar to all other celestial objects. And YES the polar alignement is necessary if you plan to take videoclips, especially if you'll use a long focal. If you'll take single exposure photos you don't need to align the mount.

The alignement, you can make it by (at list) knowing the cardinal points. Most of the time an approximate alignement is enough. After this app. alignement you can tweak it by following the drift of the Sun.

[allcart]

If you have alignment marks on the ground where you position the mount for night use, you can use the same marks for solar use. The better the alignment, the better the tracking. Although this is not so crucial for solar AP as the subs are really short and long exposures are not needed. Exposures are usually far less than 1sec so alignment and tracking don't have to be super accurate.

White light AP is just the same as planetary AP except that you have solar filter on the front of the scope.

DANGER WARNING.... DON'T FORGET TO PUT ON THE SOLAR FILTER, AND PUT A SOLAR FILTER OR A CAP ON THE FRONT OF THE FINDER.

[andrew s]

As the previous comments polar alignment is a good idea, however, the solar rate is not the same a sidereal rate and as the track of the sun is also not constant in declination so expect to make some adjustment. The plus side is that stacking software can cope with small drifts and in the past I have used manual slow motions on an alt az mount and got reasonable results.

Regards Andrew

[allcart]

Thats a valid point Andrew, so choose the correct tracking rate. Also don't forget you may still have to do a meridian flip at 1pm.

[kirkster501]

Can you use your normal EP's, cameras etc when viewing the sun, with the obvious proviso that the filter is securely fastened to the front of the scope?

[StevieDvd]

Can you use your normal EP's, cameras etc when viewing the sun, with the obvious proviso that the filter is securely fastened to the front of the scope?

Basically yes. You can get different solar filters for visual & photographic but as long as the filter is safe then the usual viewing/camera options are there.

[JamesF]

Polar alignment helps for solar imaging in my experience, but I believe Steve Ward does a drift alignment on a sunspot as an alternative to aligning with Polaris if he's imaging away from home.

James

[michael.h.f.wilkinson]

I have always found that setting the polar axis to the current latitude, and pointing it north is sufficient for short runs. Drift aligning is required for longer programmed exposure sequences. So with the EOS, taking a series of single frames at full photographic resolution (i.e. no video mode), accurate alignment is certainly a bonus, or you need to adjust between frames (bit of a pain, but doable). When using my ASI130MM planetary camera, rough and ready is enough, because it captures 1000 frames in 50s with ease. Drift is minimal in that period.

[JamesF]

Good point, Michael. With my 450D and 127 Mak I get very close to a full frame image, so good alignment is pretty much essential.

James

[StevieDvd]

The software DSSR (Dave's Solar System Recorder) is quite a useful tool for solar work. It can do basic guide control using the imaging device to keep the sun tracked amongst other nice features.

[Steve Ward]

As James said I used to drift align when away from the fixed position I have marked at home.

But these days I find it's just as easy to monitor the discs drifting frame to frame ( using the Quick-Preview box in Utilities) as it is to faff about aligning to start.

The main reason being that I use the EQ3-2 away from base that has no Solar tracking rate , so I still had to tweak it every now and again anyway.

I've found it second nature now to be tweaking the mount controller with the right hand while tweaking exposure and focus with the left hand ...

One tip for a slightly mis-aligned set-up , when you've got the disc on screen , monitor the direction of the drifting and orient the camera so that the disc moves across from L-R or R-L on the longer axis of the chip ( DSLR here ) It gives you more time to grab frames before readjusting .( You can rotate the final image later after processing to keep things the right way up)

[DrRobin]

In my experience Polar alignment or any other type of alignment is not necessary. I simply point my mount north and then slew round (if using goto) or manually push it round until the sun is in the finder. After that tracking is fine for a few minutes. If you have buttons on your tracking, you can always nudge it around if it drifts too far, that is what I do.

Actually, it helps for the sun to drift a little in the frame of an AVI, it evens out the pixels and when the image is stacked gives a smoother output.

As for eyepieces, barlows, cameras, yes they can all be used subject to having the blocking filter in place. Meade sell Cemax eyepieces and barlows, with special coatings for Ha, I have the 25mm and the 2x barlow and in my opinion you would be just as good with ordinary astro eyepeices, the coatings don't seem to make much if any difference.

Robin

[thenews24]

I have no view of Polaris from my home, so even at night I can not polar align. What I do is go somewhere at night with the mount that has a view of Polaris, and get the most accurate polar alignment I can. That way when I return home, I have eliminated altitude, so all I have to worry abut is azimuth to get an accurate true north position. (My mount has inaccurate altitude readings so I cannot rely on just setting it to my latitude).

With altitude eliminated, I do drift alignment and only adjust azimuth. Basically see where a sunspot drifts, adjust azimuth to see if it corrects it or makes it worse until I have eliminated the drift. Takes some time but worth it. And it's always best to know the orientation of RA drift. Sometimes my 'guide sunspot' only drifts in East or West, which usually means I have the mount imbalanced.

[Steve Ward]

That's pretty much how I used to do it . . .

But I've found that the wonderful British weather generally requires a very rapid set-up , i.e. plonk the mount down asap and get shooting before the gap disappears , and worry about the drift later when the subs are in the bag .....

We do get the occasional relaxed sessions with wall to wall blue , but they are getting rarer .....

[David Smith]

I have no tracking on my mount at all, just orient the camera so the sun's disk drifts across the long axis of the frame and shoot as many frames as I can in the time it takes to cross the frame. I can get more than a hundred frames in the 90 or so seconds it takes to cross the frame. I then use PIPP to crop and centre the frames before stacking etc.