Lee_P

Welcome!

I use a 2600MC-PRO and it's fantastic. Its strong reputation is well-deserved. Just a shame it's expensive!

I think that these are great, and also cover quite a variety of targets -- wide-angle Milky Way with landscape, Moon, planets, all from a first collection. Bravo!

Great that you can see the dust lanes with just 45 minutes of integration time!

Nice shot, I do like wide fields of view that capture the whole nebula.

18 hours ago, barbulo said:

Good job Lee. Great source of knowledge for rookies like me. Thanks!

Happy to hear that   

Feel free to suggest content that you'd find useful and maybe I can add it to the list!

3 hours ago, fozzybear said:

Lee, Well done there a great site with lots of info

Andy

Thanks Andy, I've got a few ideas for new articles too -- just need the time to write them up!

Great picture, especially as it's a work in progress. Impressive for six months too!

2 hours ago, rwilkey said:

Hi Lee, impressive!

1 hour ago, MARS1960 said:

Looks good Lee. 

Added to my bookmarks bar .

1 hour ago, Andy R said:

Good job, added to my favourites.

Thanks all, good to know I've got at least three views..!

Hi SGL-ers,

I've been wanting to learn how to make a website using WordPress for a while, but needed a good idea for what it should be about. I settled on my astrophotography, figuring that making the website would be more fun if it's about something I'm interested in! In particular, I opted for the niche of OSC imaging from a city, because that's what I do, and the content may actually be of some interest to other folks out there. 

http://urbanastrophotography.com/

It took a while to build because I was learning from scratch, but it was a good use of Summer's lighter evenings! I hope that some people will find it useful. My aim is to update it with some new content every month or so.

-Lee

Hi and welcome! I'm from Weston too, living in Bristol now. Great photos you've taken

14 hours ago, Luke Newbould said:

@Lee_P - Hey mate! - It sounds like a good idea, definitely worth testing out! my only question would be will linearfit stretch the midtones/highlights the same way as the manual process does, or will it just make the background levels match? 

interesting to see how it works mate!  

It worked out OK I think! Maybe I was just lucky with the G channel being fairly strong anyway.

Hi @Luke Newbould, I'm reprocessing another image using your method. I've made a slight change, and am wondering whether this it's something you didn't do on purpose -- if not, it might be a neat optimisation. Basically, I'm at the stage where you've split the channels into R G B. You've deleted B, and are using Curves and HistogramTransformation to make G look like R. What I'm currently trying instead to achieve this is to open up LinearFit, use R as the reference, and then apply to G. I *think* that achieves what you're aiming for with the Curves / HistorgramTransformation steps, but is simpler. Or maybe I'm missing something! Whaddya reckon?

Thanks,

-Lee

I had a QHY5 many years ago. I've fished out the driver I used (ASCOM-compliant). Fingers crossed it's helpful to you!

QHY5ASCOM-V40.zip

https://www.qhyccd.com/download/ <- "For Discontinued devices which are not listed above, please contact us." You could always email QHYCCD and ask, if the driver I found is no good.

-Lee

I reprocessed some old data using Luke's technique. Happy to get some blue into my L-Extreme data!

Very nice!

On 11/06/2021 at 15:58, Ouroboros said:

Cracking image! Leaps out of the screen. I’m quite amazed that such an image is possible in Bortle 8. It kinda confounds the statement that mono is required for such conditions. 

Thanks! I get that mono is objectively better, but when I hear people say that you have to go mono if you're in a city, I kinda want to show them what can be achieved with OSC and an L-eXtreme... 

21 hours ago, Luke Newbould said:

@Lee_P WOW! - That looks absolutely awesome mate, I love that you've really worked the data hard and got every ounce out of it - extremely inspiring stuff!!

Thank you so much for crediting me too mate, I really do appreciate that you'd do that! 👍

Haha no worries, I've been trying to get nice blues into my images for a while, and your tutorial completely cracked that one for me 😁

Sorry to hear about the thefts!

I used to image with an 80ED too, and am now using an Askar FRA400 (https://www.firstlightoptics.com/askar-telescopes/askar-fra400-f5-6-72mm-quintuplet-apo-astrograph.html) It's a good upgrade to the 80ED, and reasonably priced for the quality. I wrote a review for it in the members' equipment reviews section. Looks like there's a long lead-time for it on FLO though.

I'm having a good time pushing what I can achieve with an OSC camera (plus L-eXtreme) from my city centre location. I think this is my best attempt so far. I push the data hard, which isn't to everybody's taste, but I quite like the "punchy" effect.

* May and June 2021
* Bristol, UK (Bortle 8 )
* Telescope: Askar FRA400 f/5.6 Quintuplet APO Astrograph
* Camera: ZWO ASI 2600MC-PRO
* Filter: Optolong L-eXtreme
* Mount: Orion Sirius EQ-G
* Guide: William Optics 32mm; ZWO ASI 120MM Mini
* Control: ASIAIR PRO
* Software: PixInsight, Photoshop, Lightroom, Topaz DeNoise AI
* 480 x 120 seconds
------------------------------------------------------------
Total integration time: 16 hours
------------------------------------------------------------
By Lee Pullen

Huge thanks to @Luke Newbould for making an excellent PixInsight tutorial, which I used as the basis for my processing. https://www.youtube.com/watch?v=QV6ObLVRvNk

Thanks again for making the tutorial. It's pitched at a perfect level for me (and we have the same camera and filter!) I used your tips to help edit this Elephant Trunk photo. Amazing what we can do nowadays with OSC cameras even in light-polluted skies (I'm in Bortle 8). I'm definitely interested in any more videos you make! 

Thanks @vlaiv, you're a legend! From visual inspections I thought that the D3 was having minimal impact one way or another, but it's so much better having numbers to compare. 

38 minutes ago, vlaiv said:

Well, there is obvious difference between the two - one without filter has much higher average signal level in the sub:

I assume that these are taken successively and that conditions are pretty much the same?

Do you have calibration frames for them? At least darks? That way we can actually estimate SNR difference in some part of the image.

In the mean time I can estimate gradient (not very precise as there is vignetting) in each image and compare them

These are gradients "normalized" one against another - this shows that one without filter is much larger and in comparison, one with filter is almost no gradient at all - it just looks like gray background (but in reality, there is a bit of gradient as there as well)

So first iteration of gradient estimation for filtered version gives about 61ADU of difference between brightest and darkest part of gradient.

While no filter version has 137ADU gradient.

Btw - these are gradients of binned version of the image - that means R, G and B data combined / added together. If you like, I can do comparison of each channel for you, but I'd rather do that on calibrated subs as it makes more sense.

Thanks vlaiv! Here are some dark files. To answer your questions: yes they were taken almost successively and with the same conditions; and RGB combined sounds just fine, especially if it's quicker for you.

Dark.rar

@Magnum Ok, two subs attached, both taken last night -- should negate any differences due to sky conditions. One IDAS D3-LPS, the other No Filter. Do you think there's an appreciable difference? @vlaiv, it would be great to get your opinion on these too, if you have time 😁

M81_NoFilter_120s.fit

M81_D3_120s.fit

I can't speak specifically about Canon cameras, or using them for astro -- but I've used Nikon DLSRs for years for professional photography work. and now am using a Nikon mirrorless. Mirrorless is definitely the future! I wouldn't consider a DLSR now. Mirrorless all the way 😁

Thought I'd join in the fun. About 15 minutes of editing time, mostly using PixInsight, then a little bit of Lightroom. I pushed it too far so it's noisy, but I reckon you've got some good data in there. I could do more but need to collect my daughter from nursery 😁