13 replies to this topic

[divers]

So much overlap with this question but decided on this forum.

 

i was looking to upgrade my asi462 planetary camera to something like the asi533.  But, then i realized the frame rate on the 533 at 20fps is actually slower than the frame rate on my t7i at 29fps in live view mode.  I realize neither camera is optimal for planets, but it would seem the T7i is “better” than the 533 if I wanted to use for planets?  Am I missing something? 

[Tapio]

Asi533 is better because you use ROI which means much higher fps.

[divers]

Understood.  I think I will just stick with my DSLR for now.  Its a nice match for my 180mm mak even with slower frame rates.  I like the bigger chip when I image the moon.  

[steveward53]

Problem with the Canon 'video' is that it's just a stream of compressed jpegs from the livestream , low quality and not good for planetary.

 

And you can't save straight to a laptop but only onto the SD which makes tethered shooting a pain.

Edited by steveward53, 28 February 2024 - 07:53 AM.

[gstrumol]

Problem with the Canon 'video' is that it's just a stream of compressed jpegs from the livestream , low quality and not good for planetary.

 

And you can't save straight to a laptop but only onto the SD which makes tethered shooting a pain.

I assume you're referring to when you use Liveview @ 5X and simply record the screen images, yes? But then aren't you saving directly onto the laptop because you're recording what is on the laptop screen?

 

In any event, here are some images I took of Jupiter and Saturn using my Canon T7 with both the Apex 90mm Mak and the C8:

 

(click to enlarge)

 

These were shot using the video function (30fps, 1/30s SS - yes, I should have used a faster SS!) with Lucky Imaging. Since I don't have tracking (manual mount) I just let the planets scroll across the FOV and use the slow motion knobs to swing them back. Typical video length was 90s each. I then transferred all the files from the DSLR to my desktop via cable (I don't have a laptop either).

 

They're not the greatest planetary images, but I don't think they're bad either. 

 

But I do agree, a dedicated astrocamera and a laptop would be the way to go for even better images.

[steveward53]

I assume you're referring to when you use Liveview @ 5X and simply record the screen images, yes? But then aren't you saving directly onto the laptop because you're recording what is on the laptop screen?

 

In any event, here are some images I took of Jupiter and Saturn using my Canon T7 with both the Apex 90mm Mak and the C8:

 

Planets2023J.jpg

(click to enlarge)

 

These were shot using the video function (30fps, 1/30s SS - yes, I should have used a faster SS!) with Lucky Imaging. Since I don't have tracking (manual mount) I just let the planets scroll across the FOV and use the slow motion knobs to swing them back. Typical video length was 90s each. I then transferred all the files from the DSLR to my desktop via cable (I don't have a laptop either).

 

They're not the greatest planetary images, but I don't think they're bad either. 

 

But I do agree, a dedicated astrocamera and a laptop would be the way to go for even better images.

No , as I said you cannot save direct to a computer as you can with individual full frames , you have to remove the SD regularly to download the video to the PC.

 

My first DSLR 'upgrade' was from a 1000D to the 1100D for the video function , I immediately realised it didn't work and sent it back .

 

Even my 'new' 90D won't record direct to PC.

 

And the video is highly compressed jpeg stream not AVI quality , hence the lack of detail you can capture with dslr in video mode.

 

The sooner you get that mono camera and laptop the happier you'll be ... 

[gstrumol]

No , as I said you cannot save direct to a computer as you can with individual full frames , you have to remove the SD regularly to download the video to the PC.

 

My first DSLR 'upgrade' was from a 1000D to the 1100D for the video function , I immediately realised it didn't work and sent it back .

 

Even my 'new' 90D won't record direct to PC.

 

And the video is highly compressed jpeg stream not AVI quality , hence the lack of detail you can capture with dslr in video mode.

 

The sooner you get that mono camera and laptop the happier you'll be ... 

You're probably right, but I still like my planetary images! 

 

However, I never have to remove my SD card to download the video to my desktop. Using the EOS Utility I simply use a cable from the DSLR to the desktop and the utility transfers any or all of the images or videos to the desktop.

[gstrumol]

One other point: it also depends on the target and the size & level of detail you're going for.

 

Here, for example, is a single shot with the AT80EDL and the T7 of the gibbous moon:

 

 

and here is the sun in Ha taken with a SS PST and the T7 in video mode (compared against others on the same day with larger scopes and dedicated astrocams):

 

(click to enlarge)

 

Of course, those other images have much more surface detail that would be revealed at full image size, but you get my point.

[divers]

Its hard to beat the real-estate of the t7i for the price.  The pixel size works great at f17.  I can live with the lower fps for now.  I have the zwo462 that I am going to sell and I "think" buy the Ares-C pro from player one for planets and granular imaging of lunar craters.

 

Thanks all.

[divers]

BTW - I use backyard eos with 5x live view with the t7i and have been satisfied for what its worth.

[steveward53]

 

However, I never have to remove my SD card to download the video to my desktop. Using the EOS Utility I simply use a cable from the DSLR to the desktop and the utility transfers any or all of the images or videos to the desktop.

I only have to remove the card because I only shoot video when capturing ISS transits and/or wildlife stuff with the 90D out and about on the fly , either handheld or on a tripod.

 

My USB cable is permanently plugged into the 6D (in a loom with my autofocuser USB cable and HEQ5 Pro handset cable) on the Evostar 150 solar rig ready to plug straight into the laptop to be shooting at a moment's notice ... 3 minutes from opening the summerhouse doors to capturing data ... 

[BQ Octantis]

So much overlap with this question but decided on this forum.

 

i was looking to upgrade my asi462 planetary camera to something like the asi533.  But, then i realized the frame rate on the 533 at 20fps is actually slower than the frame rate on my t7i at 29fps in live view mode.  I realize neither camera is optimal for planets, but it would seem the T7i is “better” than the 533 if I wanted to use for planets?  Am I missing something? 

The ASI533 does 20 fps in 14-bit mode γ=1 (i.e., linear) raw channels.

 

The Canon LiveView output is 20 fps in 8-bit mode γ=2.2 (i.e., gamma compressed) on a CCM applied to the raw channels.

 

8-bit γ=2.2 CCM mode works great for planets—even for Mercury—and for contrasty lunar features along the terminator:

 

(Click for full size)

 

But for an extremely uniform, low-contrast target such as a full moon, Venus, or the surface of the sun, 14-bit linear is the only way to get color contrasts without stretch rings (from the 8-bit quantization error). And the only way to get that from the Canon is raw capture at ≤1 fps:

 

 

 

Skywatcher Mak 180, Canon 600D/T3i, 3-panel mosaic, 12×1/40sec ea.

 

Cheers,

 

BQ

Edited by BQ Octantis, 29 February 2024 - 05:00 PM.

[ErwinL]

Unfortunately, the T7i is not supported by Magic Lantern, but if you have an older 60D on hand, with Magic Lantern you can shoot uncompressed 14-bit raw video at up to 50 fps, center cropping down to 640x512 at full sensor resolution.

[steveward53]

Unfortunately, the T7i is not supported by Magic Lantern, but if you have an older 60D on hand, with Magic Lantern you can shoot uncompressed 14-bit raw video at up to 50 fps, center cropping down to 640x512 at full sensor resolution.

I've looked a ML a number of times but there are too many caveats throughout the website for my liking ...