ecuador

I really don't understand why SkyWatcher doesn't just install it "upright" in factory, like other manufacturers do, since they seem to align it anyway. I have edited those instructions on Polar Scope Align quite a few times, but I still get questions from confused people  

BTW the previous version of PS Align Pro required the device to be pretty level on the horizontal axis to get an accurate compass reading. Version 5.0 released recently lets you mount it at any angle, as long as the top of the phone points to the celestial pole.

On 04/12/2019 at 18:24, SmokeyJoe said:

Thanks for your reply, you are right about putting 6 at the top but there is also a diagram of Cassiopeia to help alignment, this is in completely the wrong place.  

I think you are confusing Cassiopeia with Octans, which is used for the south hemisphere. I mean, you are talking about this reticle, right?

So, Octans is irrelevant, in fact in my app (I am the developer of Polar Scope Align) when you are in the N. Hemisphere it doesn't even show you Octans, it just zooms in the center. I could allow a rotated view for people who can't rotate the scope enough, but Jiggy 67 is right, in the end you just need a vertical reference, you can just put 6 on top instead and imagine it is 0.

35 minutes ago, Adam J said:

Yep it definitely worth remembering that a EOS clip filter is just a 1.25 inch filter in a different mount that allows it to be held very very close to the sensor. A fact that I find deeply annoying given that the Clip filters cost so much more than the 1.25 inch equivalents for no real reason.  Problem with the approach you linked though is what do you do if you are using a coma corrector?

Also a slight warning, some filters (normally narrow band filters) are actually directional. So threading them on in the way shown in your link may have unknown consequences to their performance. 

Yes, the cost of the clip filters is very annoying, isn't it?

The DIY solution I proposed is for anything that lets you use a regular T-ring. In my case it works fine with my TRF-2008 reducer, my TSFlat2 flattener and even my F/6.3 reducer/corrector. However, it won't do with the Skywatcher correctors that have a 48mm thread and require a 55mm distance (so there has to be an M48 ring on the camera).

As for the directional filters, you missed the part where I show how to attach it in that case (the sensor distance increases slightly - but you can't have everything!).

As mentioned, you can get away with using 1.25" filters even on APS-C sensors if you manage to get them close, and I manage to do that even for a DSLR that normally "keeps you at distance" - see here for a little DIY - and vignetting left is minimal at the extreme corners. Some filters are quite expensive at 2"... 

3 hours ago, James said:

I don't want to be told that I need more colour in the image ...

 

Eh, what do you mean more color? It already is too red!

Nice one, favorite target...

54 minutes ago, ollypenrice said:

As I said, I'm not aware of anything to beat DBE. That means what it says - I'm not aware of it. I don't claim that it doesn't exist! I'm not in the business of trying every new bit of software that appears on the market and I suppose that I'm mainly motivated to try new software when I see an image that breaks new ground. If I think, 'How did he or she do that?' then I'll be in there, full of curiosity. I'm hardly a PI evangelist, I'm manly a Ps imager, but DBE is profoundly impressive. If you have an alternative, tell us about it. Give us some demos. I'm all ears, I promise. If there is something out there which is more sophisticated than DBE - great.

Olly

No reason to get defensive, I assumed you had not tried StarTools' wipe, otherwise I am sure you would have mentioned it - it is equivalent. And, no, I don't expect you to try every software out there, it was not an accusation, just trying to be helpful 

As I said, my personal experience was: Trying PI... interesting... DBE... wow! Then trying StarTools... interesting... Wipe... wait, it did it with just one click? -> back to DBE to compare... yes, same result. So it is not about "better", it is about giving me the same result with one click for 90% of the cases, while with DBE I did a bit of setup. In the other 10% of the cases, Wipe also has to be assisted (masks), although still probably faster to do than DBE depending on the case. Overall, I can't claim StarTools will give you a better result - I didn't get that advanced in PI during trial to be able to say that, but after trying both (actually spending a bit more time with PI since it is less straightforward), I could get a similar result in about 10 mins (with ST) instead of 1 hour+ (with PI). And I loved the fact that most modules of StarTools are not destructive on your data you can go back and forth, apply as many stretches as you want etc, so I personally find it more pleasant to work with. Now, if you want things like batch processing etc, you can't use StarTools, so, again, that is my experience as a relative beginner. I posted a link to my tutorial if you are curious (I selected an example where wipe needs a little help), there are also many videos on youtube to get an idea. It is interesting to see once in action, just because it does not look like any other program...

I would want to keep PI for calibration/stacking, but it felt too expensive for just that - I already have Photoshop if I want a little tweak after StarTools - so I had to go back to the rather temperamental DSS

36 minutes ago, ollypenrice said:

DBE in Pixinsight has no rival of which I'm aware.

Eh, I assume you haven't tried the "Wipe" module? I had first tried the DBE module of PI (trial) and loved it (coming from Photoshop). When I switched to StarTools with its wipe module, DBE actually felt like a chore

4 minutes ago, bottletopburly said:

+1 for Startools and also +1 Ecuadors tutorial ,excellent startools guide , Ivo jager  the developer of startools rates pixinsight pureley on it`s stacking capabilities  alone .

Yeah, I'd actually appreciate a cheaper stacking/registering-only PI version to replace the free DSS  

2 hours ago, happy-kat said:

Why don't you also review the trial of startools £34 Pryce for startools or there abouts

+1 for that. StarTools is free to download and try for as long as you want with all features - only save is disabled (screenshots work) - and if you end up buying it, it is very cheap. When you get used to it, it takes 10 minutes to give a good result on an image, when it took me over an hour with other software for similar (or worse) results.

Edit, oh, I forgot, you might want to check out this quick tutorial I made recently for my astro club.

It looks nice. Modding your 450d will make it about 4x more sensitive in such targets. Then again, you are not in the UK like I am, where we rarely have 5 hours straight without clouds, so we have to make every minute count  

3 hours ago, Nigel G said:

Thanks for the link. 

I guess I Neen to find the best settings for my cameras, 

All knowledge and improvement though 

Nige.

The rule of the thumb with your 1200D (and most reasonably recent Canon crop) is to use ISO 1600, unless a lower ISO will allow you to go for a longer exposure.

Good explanation: http://dslr-astrophotography.com/iso-dslr-astrophotography/

On 11/2/2016 at 20:57, Nigel G said:

Correct me if I'm wrong but a 30 second exp at 6400 ISO = 120s at 1600 ISO but with more noise.

 

This is completely wrong. It is from the common misconception that ISO has something to do with sensitivity to light (like in the film days). At both ISO 6400 and 1600 the amount of photons detected are the same and depend on the QE of your sensor, which is fixed. ISO is an amplification applied AFTER the detected photons have turned to electrons and we raise the ISO in astrophotography because it is applied before the ADC, so on cameras with noisy ADC we manage to drown that noise with a stronger incoming signal (but we can't do anything about the sensor noise which gets amplified with ISO). In fact, going to ISO 6400 for most cameras is beyond the useful ISO range (since high ISO is applied digitally after the ADC), so it does not give you anything.

If you take a 30 sec at ISO 200 and a 30sec at ISO 3200 both in RAW and assuming the ISO 3200 has not clipped the highlights, and then stretch the histogram equally, you will have the same result and on some cameras (Canon crop DSLRs for example), the ISO 3200 will have just a little less noise because of the reason I mentioned. 30 sec at any ISO is always worse than 120 sec at any ISO (after you stretch them equally) because you have captured 4 times less signal (photons).