A tip for a beginner

Andrea is right, any kind of tracker would help. You could build something as simple as a barn door tracker all the way up to a computer controlled EQ mount.

https://www.youtube.com/watch?v=zvoH3D_vAMg&t=13s

Have fun!

Tony Gondola · Jul 17, 2026, 04:46 PM

Andrea is right, any kind of tracker would help. You could build something as simple as a barn door tracker all the way up to a computer controlled EQ mount.

https://www.youtube.com/watch?v=zvoH3D_vAMg&t=13s

Have fun!

A homemade barn door tracker would indeed be ideal—even though it looks like a lot of work—but given the high cost of trackers here in Brazil, I might just venture into building one. Thanks a lot for the tip!

Robin Bosshard · Jul 17, 2026, 04:51 PM

You can use Sequator or software like it to stack even untracked images to some degree. But the next step up would be a tracker for sure!

Clear skies!

I am using Siril and Sequator; so far, I haven't achieved a fully satisfactory result due to my equipment's calibration. I plan to use a mask to fine-tune the focus and conduct shorter sessions to get a good result.

Lucas Nomade · Jul 17, 2026, 06:10 PM

Robin Bosshard · Jul 17, 2026, 04:51 PM

You can use Sequator or software like it to stack even untracked images to some degree. But the next step up would be a tracker for sure!

Clear skies!

I am using Siril and Sequator; so far, I haven't achieved a fully satisfactory result due to my equipment's calibration. I plan to use a mask to fine-tune the focus and conduct shorter sessions to get a good result.

At 50mm I found 5 sec was the limit. Even then results were not great :)

What length of subs with which focal length are you using?

Xavier SOBRERO · Jul 17, 2026, 07:37 PM

Hi,

The maximum exposure time is 30 seconds when using a fixed tripod. After you need to move your camera for keep a fixed reference point at the center of the objective.
My first photograph of the sky using this technique : https://telescopius.com/pictures/view/33586/wide_field/ngc-6374/by-xavs?gallery_order=is_featured&gallery_username=XavS

You'll succeed by trying different approaches. ;)

Good sky

Xavs

Actually the max. exposure time will vary depending on focal length. 18mm might be ok at 30 sec. but 105mm won’t be. It’s best just to do test exposures of increasing length until you start to see objectional trailing.

A more precise one is to take the value of the FWHM in arcsec of the stars in the center of the frame (with a very short exposure or pointing at the Pole) and divide this number by 15 and then divide by the cosine of the declination of the object you’re shooting (i.e., the smallest of the declination value in the frame) to get the exposure in seconds.

Xavier SOBRERO · Jul 17, 2026, 07:37 PM

Hi,

The maximum exposure time is 30 seconds when using a fixed tripod. After you need to move your camera for keep a fixed reference point at the center of the objective.
My first photograph of the sky using this technique : https://telescopius.com/pictures/view/33586/wide_field/ngc-6374/by-xavs?gallery_order=is_featured&gallery_username=XavS

You'll succeed by trying different approaches. ;)

Good sky

Xavs

Thanks for the tip, I really liked your photo!!

Tony Gondola · Jul 17, 2026, 08:59 PM

Actually the max. exposure time will vary depending on focal length. 18mm might be ok at 30 sec. but 105mm won’t be. It’s best just to do test exposures of increasing length until you start to see objectional trailing.

Yes, I’m struggling a bit with the stacking due to the trails, but I’m learning more and more and getting closer to the ideal with each passing day.

https://astroworldtelescopes.com/products/og-star-tech-star-tracker-v2?sca_ref=5444398.WZu4xh9hND

You may like this and it is a low cost excellent solution

Earlier this year in South Africa, I used Siril to stack 400 X 30s images of the Carina Nebula, taken with my Nikon DSLR. Focal length was about 150mm and I used a tripod with no tracker. I had to reposition the camera several timed during the evening to keep the Nebula more or less centered in the field of view.

The stars were elongated but I used the RC-Astro BlurExterminator tool to “Correct” the stars and it did a fantastic job. You have to pay for BlurX but it now works with Siril.📷 carina_dslr2.jpg

Thanks TiffsAndAstro

I need to make a correction here…

Unfortunately I didn't write down the settings and I no longer have the original Nikon NEF files and I am relying on my poor memory.

I was using a Zoom lens so it may actually have been closer to 100mm focal length. Also I am now thinking that these might have been 15 second exposures…

The point that I was a trying to make is that some modern software tools like BlurExterminator can correct elongated stars to a certain extent.

Also, two more things were working in my favor:

• The Carina Nebula is close to the South Celestial pole, so star trailing was much lower than it would have been in a different part of the sky

• I was in a place with very dark skies and no moon, so short exposures gave me a lot of detail compared to a more light polluted location.

Neil