Nerf_Caching

Sombrero galaxy using stock Nexstar 5SE, astromod 450D and bortle 9 sky without filters. 29x30 secs at ISO 800.

How's this for only 5 subs of 90 seconds each? I was using a Tamron 28-300 lens at 200mm on a stock Canon 650d, but it dewed up not long after I started my session, plus I got clouded out anyway! Mount was a SW star adventurer, shooting under Bortle 5 skies.

Taken a couple nights ago with a stock Celestron Nexstar 5SE on its alt-az mount, featuring M2. Camera was a stock Canon 650d without any LP filters used. 30x15 seconds at iso 3200 under Bortle 9 skies.

Just now, pointedstick said:

Thanks for the information. I think I understand that the smaller the pixels in your imaging sensor, the harder the rest of the equipment has to work to actually make use of the high resolution. Do I have that right?

However, I'm not sure I follow when you say that focal length is not really that important. Please correct me if I'm wrong, but if you stay within the 1-2 arc-seconds per pixel guideline and use a low focal length scope where the object is small in the image frame, won't the object occupy fewer pixels compared to using a high focal length scope where the object will be larger in the frame and occupy more pixels?

FWIW dew is never going to be a problem where I live. The only time it ever gets wet enough for there to be condensation outdoors, the skies are cloudy so you can't do any astronomy anyway.

What is "OAG"?

Off-axis guider. It is when you have a guide camera sharing the same scope as the imaging camera using an OAG to reflect some of the incoming light to the guide camera.

The row labelled "Time" has three colors: Red, Amber and green. The time follows 24-hour clock. Let's say that the time '20' was colored red for a given night. That means that it will be cloudy and unsuitable for stargazing at 8pm. On the other hand, if the time '01' on another given night was shaded green, it will likely be clear at 1am. Amber color means that conditions may not be great, but there may still be gaps in cloud or some thin, high-altitude clouds which may hamper stargazing. Between times '23' and '00' on the interface, you'll notice a red line running vertically under it starting from the row labelled 'Total cloud' all the way down to 'Humidity'. This denotes the border between one day and the next. As with the sunlight row(under time), yellow color denotes daytime, while the shades of blue indicate twilight and black being nighttime. For example, if the black region starts at time '20' and ends at '04', it means that your nighttime will last from 8pm to 4am the next day. For the row under sunlight named 'Moon', it shows us when the moon will be out. This is important for astrophotographers as moonlight washes out faint detail in deep-sky objects. A silver bar indicates when the moon is above the horizon and works in a similar manner to the 'sunlight' row. The four rows underneath show percentages of cloud cover for low, medium, high and total cloud cover for a given time of day. Moving on to ISS row, a space station icon under a given time of day indicates when the ISS will pass over your region. It will look like a moving star across the sky if a pass occurs during nighttime or twilight. The rest of the rows follow a similar concept and the values listed are either percentages, distance(for visibility), units of speed(for wind) or degrees celsius(for temperature). The rows named 'rain' and 'frost' follow similar concept to 'ISS' row. Hope this helps!

On 05/03/2021 at 20:18, LeeHore7 said:

I'd be interested in this also after the review in the sky at night magazine, I have a star adventurer and 72ed ds pro on order so be good to here what others are achieving unguided as this is what I'll be doing. 

 

Clear skies 

I achieved this using 45-second exposures with a 72ED and SA mount. Make sure declination axis is properly balanced using a dovetail saddle and a longer dovetail on the 72ED to ease the stress on the tracking motors.

1 hour ago, Miguel1983 said:

Hi, 

did you use dither ? 

No I did not dither as I used a star adventurer.

Hi all. I tried photographing the Bode's and Cigar galaxy last night under Bortle 9 skies, but my final stacked image had a really mottled background after gradient subtraction in siril. Even before gradient removal, my background still looked quite horrible. Can anybody offer a possible explanation for this? My 30-second subs were quite washed out in the beginning but got a little bit better as the target rose above the skyglow of my area. Any help would be appreciated. Thanks!

Tau Canis Majoris cluster taken through a Celestron Nexstar 5SE on its alt-az mount. 30 x 30 seconds with an astro-modified Canon 450d.

30 minutes of 45-second subs from Bortle 9 sky using the SA. Scope was a SW Evostar 72ED attached to a Canon 450d (astromod) dslr. I used an Astronomik CLS filter. A very noisy Rosette Nebula but happy so far!

Wow that's a superb attempt for a first! You might want to consider investing in the Celestron NeXYZ phone adapter as that's what I used for that shot. It supports many different phone sizes too!

11 hours ago, ollypenrice said:

This is the kind of question you can only answer by trying various ways of combining the data, and how you combine them depends on what software you're using. Any experimentation you do will teach you a lot about processing so it will be good experience. 

Olly

I stacked the filtered and unfiltered data separately. Each has around 54-56 minutes of integration under Bortle 9 skies. The unfiltered data seems to have less contrast in the Ha signal from the Horsehead. However, it does have more detail in the Flame and surrounding reflection nebulae. Quite an interesting experiment really!

Hi all! Might be a strange question but is it okay to stack raw dslr subs of the same target that were taken with and without a filter? Context is that I normally shoot using an Astronomik CLS clip-in on my modified Canon 450D, but I stupidly forgot to put it in one session. Do I also have to take a new set of flats without the filter on? I'm a bit perplexed about how the color balancing works since the CLS results in a blue color cast in my sub frames. Thanks!

Search up a guy called "Nebula Photos" on Youtube. He shows you how to use siril to stack photos. I learned to use Siril using his resources.

Hi all, so I was gifted an iphone 12 for my birthday and I have come to realise its potential in the field of photography. FIrstly, the iphone camera allows wide-field landscape photography and excellent quality video. Additionally, I realised that it had the provision of doing long exposures of up to 30 seconds! One night, I wondered whether it will do any good for stargazing. I used a Celestron NeXYZ phone adapter and a Nexstar 5SE telescope to view the Orion Nebula. What came out of a 30-second exposure surprised me. I wonder if anybody else who owns a 12 has used it for any casual EAA?

Here is how I ensure the core is not blown out in GIMP. I've illustrated it here with 6 screenshots:

1. Here I have a photo with the core overexposed. 

2. This is a layer I've made prior to the top one with a less 'stretched' version showing the core nicely(the bottom layer is just my unstretched photo. I will not worry about that.).

3. Move the less stretched layer in 2. up to the top.

4. Click Layer>Mask>Add Layer Mask. Select 'Black(full transparency)'. After selecting, it should reveal the overexposed layer underneath. Make sure that layer is toggled.

5. There should be a black thumbnail beside the thumbnail of your top layer. Make sure you are working on that black thumbnail.

6. Click paintbrush with the settings shown on the left. Make sure foreground and background colors are white and black respectively(Shown above paintbrush settings). Now color in the core to reveal detail. Double click on the top layer and click 'New from visible' after you're done.

Hope this helps. Cheers!

The Flame and Horsehead nebula are good targets for your setup. I have the same scope but on a Star Adventurer and I can get a decent image from Bortle 9 skies.

56 minutes of data on Flame and Horsehead Nebula from Bortle 9 sky. Scope used was SW Evostar 72ED, camera was modded Canon 450d and mount was SW Star Adventurer. 112x30 seconds at iso 800 with CLS filter.

My attempt at the Orion Nebula under a full moon. I used a modded Canon 450d attached to a Skywatcher Evostar 72ED on top of a Star adventurer. One hour and 14 minutes of data from Bortle 9 skies.

1 minute ago, Seelive said:

It's just about possible, this was my effort earlier this year with an unmodified Canon D200 at 400mm, 105 mins total integration. I was just happy to get something!

Nice shot! How long were your individual sub-frames?

I photographed the Lagoon and Trifid Nebula last summer using a stock dslr and 420mm refractor. Both are emission nebulae and you can clearly see that the red Ha signal is somewhat lacking; it appears more of a pink color compared to red. It still looks nice without a modded camera. Give them a try next year!

You need to focus your telescope by turning the focusing knob. The propeller shape is the shadow of the secondary mirror and the spider vanes.

7 hours ago, Spacemandan88 said:

Hi folks,

I have brought the SW star adventure for a more portable setup. Ideally for easy DSO with a small enough scope without the need for any autoguiding as such. I've been looking at the SW Evostar 72ED and the WO z61, could anyone help with some advice on these or if there's any others simlar to these.

I was also considering rokinon 135mm f2 but not too sure if the price is worth it compared to the telescopes.

thanks

Dan

Evostar 72ED is cheaper compared to Z61 but has a longer focal length. Both however are wide-field scopes and speaking from experience, I have had some good photos taken using my 72ED. If you can afford it, go for the z61 but the 72ED is also a decent budget scope. The attached image was taken using a 72ED on a Star Adventurer unguided. The camera was a stock Canon 650d with a clip-in CLS filter. 20.5 minutes of 30-second subs from Bortle 9 skies.

Here's what I've done recently on my Star Adventurer, including reprocesses with the help of Topaz AI Denoise(trial). Scope was a SW 72ED and camera was a stock Canon 650d with Astronomik CLS clip-in filter under Bortle 9 skies. Remarkable results even at 420mm focal length with 30-second subs; it really is pushing the mount's capabilities!

Just now, PeterCPC said:

Did you dither?

Peter

Unfortunately, my mount tracked too well so yes I seems that I did not dither. The object would usually shift slightly with a star adventurer.