T-mount for Canon EOS

scottw (Scott) · #1 12-10-2012, 11:47 PM

Greetings all,

I had posted this question in one of the other beginner forums but didn't get a response. I'm a bit unsure which "beginner" forums are supposed to be for what as they all seem to have a mix of the same questions.

I'm looking to try out my Canon 650D on a Celestron 130EQ. Some very careful tests without the lens attached indicate I should be able to get focus using a 2x barlow. The only thing I want to check on is what I need to get for the mount.

There seem to be lots of different brands for the TMount adapter.
Are they all essentially the same or is there any differences between them I should know about?
I'm assuming I need to get a 1.25" adapter thing for it, and likewise are they all basically the same thing (a tube with a thread on the end)?
I've seen some adapters that are priced a lot more than others, and I don't really know why that would be.

Any thought/suggestions would be greatly appreciated.
Scott.

Sarge (Rod) · #2 13-10-2012, 12:03 AM

Scott,
You will need a T-ring as well as a T-adapter. The T-ring attaches to the camera in lieu of the lens, and the T-adapter attaches to the T-ring. It is the adapter which fits into the focuser of the scope. The size of the adapter and T-ring will depend on the size of your focuser - 1.25" or 2".
Now quality wise - you will get what you pay for. Canon make their own, so they are good quality and fit pretty good, but are not the cheapest. See bintel site:
http://www.bintel.com.au/Astrophotog...8/catmenu.aspx
Lots of other makes on the market, so have a good look around first.
By the way - this will probably be the cheapest items you will purchase once you start on the astrophotography path.

Clear skies

Rod

scottw (Scott) · #3 13-10-2012, 12:14 AM

Yeah, I realise this is just the start

So the T-ring differences are really just likely to be the quality of the finish. There's no electronics or anything in them to tell the camera what type of "lens" they are?
The T-Adapter I need would be a 1.25". Bintel have one that also allows for eyepieces to be placed inside, but can come apart for prime focus. How effective would they be? I guess considering they are only slightly more than a plain adapter it might be worth trying out anyway.
http://www.astroshop.com.au/products...p?id=MAS-005J2
http://www.bintel.com.au/Astrophotog...oductview.aspx
http://www.bintel.com.au/Astrophotog...oductview.aspx

midnight (Darrin) · #4 13-10-2012, 02:19 AM

Scott,

As Rod points out, you need a T-ring for your Canon. This is the bayonet that looks the same as any EF lense bayonet that matches into the camera body. IMO, quality is not a major problem so if you buy one that is a little loose, simply wrap some teflon tape around the bayonet and build up until it is nice and tight.

The T-ring will present a T-Thread (or other if special) and then you connect whatever you need accordingly.

Good luck!

Darrin...

scottw (Scott) · #5 13-10-2012, 04:02 PM

Thanks for the info all. I was pretty sure that's all I needed to get, but it really helps to get confirmation

Went for a quick trip to Bintel this morning and grabbed a T-ring and adapter. Quick daytime test I was able to focus (mostly) on a tree a long way in the distance, but of course that's very different to moon/planets/stars so will have to hope tonight is clear to see if it can get focus with this scope.
Next step is working out what settings to use with the DSLR and get some more practice in with star alignment.

cjamo9 (Clinton) · #6 14-10-2012, 04:15 PM

i find if i can line the camera up with a bright star i use the cannon on screen zoom to get up to 10* magnification then focus the scope to land between the blue blobout and the yellowish blobout. i set my cannon eos on manual, bulb between 800 and 1600 iso. remote cont for 60s to 90s exposures for deep sky( with no remote, set for delayed shot to avoid camera shake). or movie mode for lunar and planetary focus the same way. good for planetary the eos cause of the adjustability in white balance and exp. ie no need for filters. having the t'ring will be great for safetly holdin onto you camera. Good luck and lookin forward to seeing some of your pics.

scottw (Scott) · #7 14-10-2012, 04:23 PM

Yup, worked out using the on-screen magnification trick a while ago while doing wide-field shot tests. Mine has a touch screen as well which makes it oh-so-easy.
To avoid camera shake, I use the 2 second delay timer and the touch screen trigger. The touch screen trigger is a *much* lighter touch than having to press the shutter button, and the 2 second delay is enough for any shake to stop after touching it.
I haven't setup my laptop to control it all yet, but the touch screen also allows me to start bulb exposures with a touch, and another touch to stop.
Managed to get some very quick test shots of Jupiter last night (I didn't *mean* to stay up that late). Nothing I'm prepared to publish just yet though

The telescope isn't really well suited to astrophotography, so I'm not planning to take much deep-sky stuff, but mostly play with planets/moon shots. I've actually found the camera is sensitive enough that ISO200, 1/30sec exposure and using a 13mm eyepiece in the projector adapter is enough to give me a clearish shot that shows the banding on the planet quite well.
the shots I took last night though were low on the horizon with cloud coming and going. Lots of atmosphere interference so not the best, but if I get a good clear night and decide to stay up 'till 3:00 I'll get a bunch of shots and try stacking them.

cjamo9 (Clinton) · #8 14-10-2012, 06:02 PM

Quote:

Originally Posted by scottw

Yup, worked out using the on-screen magnification trick a while ago while doing wide-field shot tests. Mine has a touch screen as well which makes it oh-so-easy.
To avoid camera shake, I use the 2 second delay timer and the touch screen trigger. The touch screen trigger is a *much* lighter touch than having to press the shutter button, and the 2 second delay is enough for any shake to stop after touching it.
I haven't setup my laptop to control it all yet, but the touch screen also allows me to start bulb exposures with a touch, and another touch to stop.
Managed to get some very quick test shots of Jupiter last night (I didn't *mean* to stay up that late). Nothing I'm prepared to publish just yet though

The telescope isn't really well suited to astrophotography, so I'm not planning to take much deep-sky stuff, but mostly play with planets/moon shots. I've actually found the camera is sensitive enough that ISO200, 1/30sec exposure and using a 13mm eyepiece in the projector adapter is enough to give me a clearish shot that shows the banding on the planet quite well.
the shots I took last night though were low on the horizon with cloud coming and going. Lots of atmosphere interference so not the best, but if I get a good clear night and decide to stay up 'till 3:00 I'll get a bunch of shots and try stacking them.

i want a touch screen now. sounds much better than my 1100d