DSRL Imaging issue

AstroBogan (Jacob) · #1 11-03-2018, 10:22 PM

So i Finally set up my gear (HEQ5 pro, Skywatcher Black Diamond ED80 with a Canon EOS 60D). Had everything set up and was observing the stars as per normal through the eye piece.

Fast forward 30 minutes and I finally decide to connect up my canon EOS 60D through a T-ring and adaptor and when I took a test 10 sec exposure the screen came out pitch black. I up'd the ISO to 3200 just to see if I could get anything and did the same thing and the same issue occured. I then removed the camera and checked the live view inside my house and was able to see what the camera was pointing at.

I went back outside and re-attached it to my gear, and again, even through live-view the screen was completely black. (Using Bulb mode). I also have the option turned on that allows the shutter to go off when there is no lens attached.

Is there something I am missing?

StuTodd · #2 11-03-2018, 10:27 PM

Perhaps you were way off focus? The DSLR won't be parfocal with an eyepiece.

Jeff · #3 12-03-2018, 12:04 AM

For first time setup, maybe try during the daytime .... say on a distant tree. That way you can work out roughly how "far back" your camera needs to be. Then tweak the focus at night time on the moon or stars.

It's possible that you just need a spacer to extend your focuser travel so that you can bring images to focus on the camera sensor. Something like one of these:
https://www.bintel.com.au/product/bi...-tubes-2-inch/

Good luck!
Jeff

glend (Glen) · #4 12-03-2018, 02:00 AM

Did you remove the diagonal mirror, and calculate the backspacing needed for your camera?

AstroBogan (Jacob) · #5 12-03-2018, 09:16 AM

Quote:

Originally Posted by glend

Did you remove the diagonal mirror, and calculate the backspacing needed for your camera?

Like I stated, I am a newbie, but yes i removed the diagonal mirror, but can you shed light on calculating the backspacing?

Quote:

Originally Posted by Jeff

For first time setup, maybe try during the daytime .... say on a distant tree. That way you can work out roughly how "far back" your camera needs to be. Then tweak the focus at night time on the moon or stars.

It's possible that you just need a spacer to extend your focuser travel so that you can bring images to focus on the camera sensor. Something like one of these:
https://www.bintel.com.au/product/bi...-tubes-2-inch/

Good luck!
Jeff

I will check that out thank you!

Merlin66 (Ken) · #6 12-03-2018, 09:23 AM

Back spacing....
The distance from the front of the T2 attachment camera adaptor to the focal plane of the camera (where the image is located) is 55mm.
You need to allow for this distance when focusing....

The eyepiece when focused is at the focal plane, the front of the T2 ring will need to be 55mm further inside focus.
Hope this helps.

ZeroID (Brent) · #7 12-03-2018, 10:49 AM

As Jeff says, do a daytime test setup, you may need an extender or some adjustment to come to focus. If you had a diag in previously I'd guess you need to need to extend the focusser further out.

Simple test just do it through the eyepiece visually. I quite often just hand hold it facing the focuser tube to get an idea of where it might be. Then rummage through my box of bits to find something about the right length.

If it's well out of focus then stars just won't even show on a short exposure, they are just giant blobs.

Startrek (Martin) · #8 12-03-2018, 03:54 PM

I’ve just recently started astrophotography with my Canon 600D, HEQ5 mount and 6” F6 reflector scope.

Have successfully photographed the moon, stars and clusters and just copied the jpegs and raw images to my PC. No processing as yet but images turned out ok ( refer my previous post in beginner astrophotography )

My Canon 600D with its T ring and 2” adapter slots straight into the dual Crayford focuser with the 1 1/4 eye piece adapters removed.

I used the moon as a test target to see if I could achieve focus.With the focuser wound in to the end , I was able to achieve focus on the moon with good image results.

Stars were also just in focus with no more spare movement on the focuser ( I guess I was lucky , my scope is an F6 )

My camera settings were as per Jerry Lodriguss DSLR astrophotography guidelines.

Settings for full moon were ISO 800 with shutter speeds around 1/1250 to 1/2000 and for first quarter moon were ISO 800 and shutter speeds around 1/200 to 1/400

I’ve tried to image Jupiter, Saturn and Mars a couple of mornings this week but ended up with pinpoints of images and when you zoom out you lose pixels and the results are horrible, so planetary imaging on a DSLR is very difficult unless you have the correct processing software and tools etc...

The golden rule in any astrophotography is get your mount polar aligned as best you can

I have no view of the SCP so I cheat and use a 1m long shadow stick set at 90 degrees on my pavement, jump on Stellarium and find the exact time of the noon meridian, and mark a line on the pavement through the centre of the shadow at that precise time.So far this method has provided a very close true south direction. Then I set up my mount along this line using a plumb bob, level the mount with both bubble level and digital inclinator, set my latitude with same level gear and then carry a 2 Star alignment and drift alignment with Synscan hand controller. It’s very crude but it works

Once again read up on Jerry Lodriguss DSLR astrophotography articles , he has a lot of good practical advice

Good luck

Clear skies !

StuTodd · #9 12-03-2018, 11:22 PM

The easiest way is to align with the moon one evening and see if you can reach focus with your set up + DSLR. Or even a far away tree on a hill.

But yeah, the focus was your problem here. We are all on a learning curve in this adventure Jsmitt94

alex-borek · #10 12-03-2018, 11:56 PM

How was the focusing? I had to move the focuser all the way to the back when using my dslr. If you cannot get to focus you should get some extenders (or some other solution, I'm sure you got enough people helping you out!)

AstroBogan (Jacob) · #11 13-03-2018, 12:00 AM

Thanks for all the advice! I really appreciate how helpful everyone is here, absolute life savers! Cheers to you people!

AstroBogan (Jacob) · #12 13-03-2018, 06:15 PM

So it turns out it was 100% the focus.

I was able to achieve focus through the DSLR on a far away telephone pole once I attached my field flattener that I received today and properly adjusted the focus.

Once the sky is no longer overcast in Sydney i'll get straight into some AP

ZeroID (Brent) · #13 13-03-2018, 07:04 PM

Excellent !
Some scopes are not well setup for photography with either too short or too long on the focal point.
Too long, an extender can solve but too short is either a Barlow to extend the focal point or having to move the primary mirror up the tube. A bit more of a mission obviously.

For a minor shift out just releasing the focuser clamp on the T-Ring and sliding it back a few mm may be enough as long as it is secure. You could then put a slip ring on the T-Ring tube to make a permanent setting. I like to have a wee bit of play on the focal point.

yoda776 (Matt) · #14 13-03-2018, 07:19 PM

Yes I can +1 to this. The moon is a good target to check against (certainly get clearer nights around here with the full moon than I do new moon!). it is a learning curve and I have been able to get some get shots eventually. even with Live view on the camera focus can be a bit tricky and not come out the way I thought. keep at it, you will get there!

Quote:

Originally Posted by StuTodd

The easiest way is to align with the moon one evening and see if you can reach focus with your set up + DSLR. Or even a far away tree on a hill.

But yeah, the focus was your problem here. We are all on a learning curve in this adventure Jsmitt94

yoda776 (Matt) · #15 13-03-2018, 07:20 PM

Glad to see. Hope you can share some photos when you get the chance.

Quote:

Originally Posted by Jsmitt94

So it turns out it was 100% the focus.

I was able to achieve focus through the DSLR on a far away telephone pole once I attached my field flattener that I received today and properly adjusted the focus.

Once the sky is no longer overcast in Sydney i'll get straight into some AP

chromus (Phil) · #16 27-03-2018, 03:29 PM

Tip for getting the focus close -> use the moon, the focus for DSO won't usually be more than 2-3mm from this.

Then use the Live-View Zoom to get focus crispy at 10x and you should get reasonable results.

Exposure wise try 60secs at ISO1600 and work from there, lowering time to get round stars and increasing ISO to get what you want.

Next step is the angst of proper polar align and guiding