Focusing with Canon DSLR and NINA, what a PITA, need some suggestions please

[Kilohertz]

I finally have everything working properly and have had a couple of good nights of capturing having just bought a Canon T3i (600D) camera and modding it to remove the IR filter, capturing images via NINA and wifi transferring images to my main computer. Using a Dell mini computer at the mount to run the setup.

My setup includes an ED80 480mm f/6 refractor, NEQ3-PRO mount guiding with PHD2, getting the hang of all of NINAs capabilities but my current struggle is figuring out an efficient focusing regime. I have a Batinov mask but it doesn't create any discernable spikes to use, the camera has live view on the LCD screen but it's small. Using NINA live view with stretch is very noisy and I can't see any stars for the noise. The only way I was able to achieve focus, which was extremely painful and drawn out, was to capture 2s exposures with HFR star analysis enabled, wait for the results, macro focus adjustment, do it again, adjust the other direction, rinse and repeat for about 20 minutes until a null in HFR was achieved. 

There MUST be a better way to focus a DSLR,  don't even mind connecting to different software to focus. I am building an autofocuser but it won't be done for a few weeks and we now finally have a week of clear skies.

Listening for suggestions. Thank you.

Cheers

[carastro]

Do you choose a bright star to focus on?  
Lock your focus when you have done so you can then move to your chosen target.  

if Nina is very noisy on live view (never used it). You could try focussing with canon utility (comes with the camera).   That is what l use.  
You  can increase your ISO just to do focus.  
 

 

Edited March 17 by carastro

[carastro]

This is a screen shot of what l get in a bright star with canon utility. 

By the way there is a zoom in facility on Canon Utility so you can enlarge the area/star you are focussing. 
 

 

Edited March 17 by carastro

[Elp]

I don't know if there is a better method than using a software focus routine, the only issue I had was the slight delay from the dslr taking the image to it transferring and the result being seen on the asiair. With the 600d I normally just took a photo then immediately viewed it on camera and zoomed in. It doesn't take long to find focus, I've done it like this many times. Can't remember whether it had a focus assist mode, most modern cameras do which helps with this task.

If you can't see bahtinov spikes as mentioned the star isn't bright enough, also try doing an extended exposure to saturate the pixels on the sensor, you might still need to zoom into the image which is why I found a bahtinov pointless as per the method above just taking images and looking at the size of the stars by eye. From experience you know what good focus looks like as tiny stars start to appear in the shot.

Edited March 17 by Elp

[Kilohertz]

Thanks all,

I'm searching for the EOS utility to see what it has to offer.

Yes, I had ISO cranked to 6400, was using one of the bright stars in the big dipper, a few weeks ago I had used Jupiter and it seemed to be bright enough to see Bat spikes, I may try that again with the Canon.

Cheers

[carastro]

I will post up some screen shots of Canon Utility that did some years ago BRB

Edited March 17 by carastro

[carastro]

 

 

 

 

Edited March 17 by carastro

[WolfieGlos]

Personally, I always used the liveview on the back of the camera with a bahtinov mask, zoom in 10x and adjust the focus to suit on a very bright star.

Then connect the cable to the camera and use Nina to control the imaging session. Now I use an EAF, which takes longer, but is a bit more accurate and useful if focus changes mid session (ie due to temperatures). 

[Elp]

That's the same as focus assist then, I never did it with the 600d as live view didn't work on my camera.

[carastro]

20 minutes ago, WolfieGlos said:

Personally, I always used the liveview on the back of the camera with a bahtinov mask, zoom in 10x and adjust the focus to suit on a very bright star.

Then connect the cable to the camera and use Nina to control the imaging session. Now I use an EAF, which takes longer, but is a bit more accurate and useful if focus changes mid session (ie due to temperatures). 

That works too depending on which angle the scope is pointing and how  many acrobats you need to do.  Lol  

Edited March 17 by carastro

[PhilB61]

Not sure why you can't see bahtinov spikes, have you tried increasing the exposure length to 5s or so. If you can now see spikes you could then use NINA to capture a 5 sec snapshot and tick the loop option, no need to save the image. Then zoom in on a bright star in the image tab, and adjust focus whilst watching the screen and the B spikes which will refresh every 7 or 8 seconds. Should be a lot quicker than 20 mins....

[Kilohertz]

Thanks everyone for the awesome ideas and suggestions.

I installed the EOS UTILITY 3.12 and it looked like it would work great, except it's drivers prevented NINA from connecting to the camera so I nuked all the utilities it installed, I may come back to it to get them to play together when it's cloudy. 

Using the camera LCD zoomed in 10X turned out to be the winner, I had no idea that function existed, I have since downloaded the manual. 🤪 I was able to get great Bat spikes on Jupiter and was focused in 30 seconds, cool! 

I've been capturing images of the Soul Nebula for the last hour but the moon is a real bother, too bad as it's otherwise crystal clear. I was amazed at how much the moon affected exposures, I could see it in my last nights images of the Heart nebula, the background noise just went away as soon as the moon set.

Thanks again for all of the help, it's very much appreciated.

Cheers

Paul

PS also happy with my mods to the NEQ3-PRO here is typical guiding.

 

Edited March 18 by Kilohertz

[michael8554]

Best to focus on a star, not a planet, with the Bahtinov Mask.

Michael

[Ratlet]

Slightly off topic, but how are you powering the camera and getting Nina to control it?  I tried before with a dummy power pack and it just kept stopping taking images after a short while.

Edited March 18 by Ratlet

[Kilohertz]

5 hours ago, Ratlet said:

Slightly off topic, but how are you powering the camera and getting Nina to control it?  I tried before with a dummy power pack and it just kept stopping taking images after a short while.

I'm using a Neewer dummy battery and simply plugged the USB port of the camera to the computer, then opened NINA and it found the camera, then just connected to it using NINA, no driver install or anything, also no ASCOM drivers for the camera, just plug n play. It's been working perfectly for 4 or 5 days now.

Good luck!

[Kilohertz]

6 hours ago, michael8554 said:

Best to focus on a star, not a planet, with the Bahtinov Mask.

Michael

Thanks Michael, as I am still learning, I'm wondering what the reasons are?

Cheers

[michael8554]

My intuition is that with a Bahtinov, a point source is best, not an Extended Object like a planet.

Why ?

I but would expect the 6 spikes to be ill-defined on a planet.

Michael

[wongataa]

On 17/03/2024 at 17:07, Kilohertz said:

I finally have everything working properly and have had a couple of good nights of capturing having just bought a Canon T3i (600D) camera and modding it to remove the IR filter, capturing images via NINA and wifi transferring images to my main computer. Using a Dell mini computer at the mount to run the setup.

My setup includes an ED80 480mm f/6 refractor, NEQ3-PRO mount guiding with PHD2, getting the hang of all of NINAs capabilities but my current struggle is figuring out an efficient focusing regime. I have a Batinov mask but it doesn't create any discernable spikes to use, the camera has live view on the LCD screen but it's small. Using NINA live view with stretch is very noisy and I can't see any stars for the noise. The only way I was able to achieve focus, which was extremely painful and drawn out, was to capture 2s exposures with HFR star analysis enabled, wait for the results, macro focus adjustment, do it again, adjust the other direction, rinse and repeat for about 20 minutes until a null in HFR was achieved. 

There MUST be a better way to focus a DSLR,  don't even mind connecting to different software to focus. I am building an autofocuser but it won't be done for a few weeks and we now finally have a week of clear skies.

Listening for suggestions. Thank you.

Cheers

Use the Lens AF plugin for NINA for Canon lens focus control in NINA.

Use APT (Astro Photography Tool).  That has Canon lens focus control and can autofocus on stars automatically.  It works well in my experience with a Canon camera and lens.

[woldsman]

Not sure what you are using on NINA.  The image tab with a 3-4s exposure on loop will always show spikes if a Bahtinov mask is used on a bright star with a broadband filter. Zoom the image as needed and turn off the loop after focusing before you go to sequencer. Only thing I can think of is that you are not targeting the bright star because the mount is lost. Rough focus and a platesolve should fix this.