1100D lcd resolution

[NCC-2893]

Hi all, looking at the specs between the 1100D or t3 and the 600D t3i I see the res. on the 600D is far better. So I presume that when you zoom in to check your focus on stars or moon or whatever the 600D would be the winner? Does the low res screen on the 1100D really suck for night sky focusing or are there other options. (for focusing) Just mulling over the pros and cons.Such a big price diff. don't want to do the wrong thing, so am taking my time gathering info. Thanks.

[Phil Leigh]

Hi all, looking at the specs between the 1100D or t3 and the 600D t3i I see the res. on the 600D is far better. So I presume that when you zoom in to check your focus on stars or moon or whatever the 600D would be the winner? Does the low res screen on the 1100D really suck for night sky focusing or are there other options. (for focusing) Just mulling over the pros and cons.Such a big price diff. don't want to do the wrong thing, so am taking my time gathering info. Thanks.

I don't use the Camera LCD screen for focussing - it's too small (regardless of its resolution) and stars are very hard to see for focussing purposes. Also, I like to save my back from further damage bending over (even with an articulated screen it's not at a friendly height).

The solution is to tether the camera to a laptop and use the liveview capability to focus on screen. There are so many advantages; the screen is as big as you need, it is easy to boost the exposure for dim stars, there is all manner of software to help with focus accuracy measurement (including fulll automation of focus!) and the same screen/method/software can be used for on-screen star & polar alignment as well as focussing (no need to disconnect the camera from the scope).

Once you have a laptop attached, the DSLR imaging capture plan (lights/darks etc) can also be automated - as it would always be with an AP CCD camera.

[kbeverage]

What Phil said. I have an 1100D and have the LCD screen disabled as running it even for brief periods can increase the temperature of the imaging sensor (it puts out a bit of heat when turned on). I use BackyardEOS for 90% of my image acquisition with the camera and the simpler (but still effective) EOS Utility that came with it for the rest. Another good program is AstroPhotography Tool (APT). As far as focusing LiveView and a bahtinov mask is the easiest way to get good focus.

[NCC-2893]

Thanks fellas. I have the laptop so I take it it simply connects via usb and load the software and just follow my nose. To be honest the ridiculous price the 1100D is going for means I really should grab it. Entry level or not other members seem pleased with their camera's so it'll do me for learning on. I'm also pleased the lcd is not really an issue.
edit: just a point about focusing, are there not instances where you focus the lens on infinity? Is there a difference between stars and the moon for instance.

[Phil Leigh]

Yes - the camera will come with a suitable USB cable. It will also come with the Canon "EOS Utility" which will let you get familiar with shooting tethered. You don't need a memory card in the camera when doing this (which also helps very slightly to keep the heat down) - the images are captured on the laptop directly from the internal memory buffer of the camera.

If you are at home and have access to AC power near the scope you can get the AC adapter kit for your camera (which replaces the battery) and keep the heat and weight down a little more. Heat (in the camera)=noise on the image. You also don't have to worry about charging or spare batteries.

You can also download fully-functional demo versions of BackYardEOS or APT to try out for a while.

The 1100D will work fine for you. It has everything that is required.

[budman1961]

+1 for BackyardEOS

Andy

[KeithBC]

are there not instances where you focus the lens on infinity? Is there a difference between stars and the moon for instance.

You always focus on "infinity" since that's where the stars are. There is no difference between focusing on stars or the Moon. Everything beyond low Earth orbit is far enough away to count as "infinity".

Unlike a camera lens, the focuser on your scope has no stop at infinity, so you have to actually focus it. And, even if you are using a camera lens for wide-field shots, the infinity stop is not accurate enough to be reliable. It is usually set a smidgen beyond infinity.

So, the normal thing is to use live view with a Bahtinov mask for focusing. On older cameras without live view, you take test shots through the Bahtinov mask. Once focused for a session, you don't have to refocus even if you change targets.

[Phil Leigh]

The thing about telescopes is that unlike most camera lenses the depth of field is effectively ZERO!... So focussing is critical and tricky....

[KeithBC]

The thing about telescopes is that unlike most camera lenses the depth of field is effectively ZERO!... So focussing is critical and tricky....

Technically, since depth of field refers to the distance out there that is in focus, the depth of field is immense. I can get everything from 240 kMiles to 300 Mly in focus at the same time!

Okay, I am being pedantic. You are right that the range of focuser movement between all that stuff being in focus and all of it being out of focus is miniscule, requiring extremely precise focusing.

[Phil Leigh]

Hence my cunning use of the word "effective" (as opposed to actual) :-)