I managed to take a couple of shots of Comet Lovejoy this morning using a borrowed Canon 1000D after my point-and-shoot wasn't up to the task. It was my first time using a DSLR and I struggled.
Focusing was my major problem. Even using the live view to zoom into and focus on a bright star I was never quite certain if I got it right. I also think I did something wrong somewhere since photos taken with approximately the same settings shows the comet tail much better than mine.
Any tips, advice welcome.
A selection of the best images and a Youtube video can be found on my blog - Comet Lovejoy Revisited
Thanks. I've also heard about focusing on something a long distance off during the day and then taping the focus ring, however that doesn't help much if you want to change between 18mm and 55mm etc. which requires refocusing for each step.
Using live view to focus on a bright star and then zooming to 10x on the LCD makes things slightly better, but the star is so tiny it's difficult to judge the exact moment of precise focus.
Focus often changes with temperature, too - making things tricky. I find wide aperture primes easier to focus than zooms since they're usually so much brighter for LiveView (don't forget to turn on the ISO expansion custom function if your SLR has it), and the optical aberrations you get with them wide open actually help focusing.
Another trick I use with my 20D (doesn't have LiveView) is to put a piece of tape on the focus ring of the lens when it's at "infinity", then take a series of long test exposures, rotating the focus ring by a notch between exposures. Zooming into the photos will quickly show where the proper focus lies (i.e. between two notches).
I took another set of images this morning. I still have to sort through them, but I downloaded Deep Sky Stacker and stacked the 1600 ISO ones. Which gave me this image. (I'm not entirely sure what I'm doing )
I prefer a more natural look to images as opposed to heavy processing, but this one (image 1) does bring out the background nicely.
I dad another imaging session, this time trying to control the camera with the EOS utility via a laptop. Not a great success. I thought focusing would be a tad easier, but in actual fact it was much harder to even see the star used to focus on and even with the zoom it was tiny on the laptop screen. I can imaging that a larger focal length lens might make it useful, but at 18mm I found the camera LCD easier to use for focusing.
I just quickly downloaded and compared a couple of images and can't see much of a difference in either the focus (camera LCD vs Laptop) or noise levels (not using live view decreasing noise).
I'll process the images after I get back from work.
Now I'm seriously contemplating buying a 1100D for myself. Still on the fence if it would be a good "upgrade" to the borrowed 1000D. Of course I can keep borrowing the 1000D at no cost, where the 1100D is a pretty penny (and that's for an entry level!). Any thoughts?
I think the major benefit would be the higher ISO capability of the 1100 since I'm shooting with a stationary tripod, so limited to 30 sec exposures. Any thoughts?
When I focus with LiveView, I'll point the camera at a small bright object (e.g. Sirius or Jupiter), put it into Manual mode, set the slowest shutter speed I can (e.g. 1/30 sec), highest ISO possible (e.g. H1 - ISO expansion), and widest aperture that the lens has.
When I turn the focus ring, I can see the star become smaller, rounder, and whiter (i.e. no red or green fringing) the closer it is to perfect focus. Another option is to get the focus close, and then find the faintest visible star on the LiveView screen and adjust the focus ring so that the faint star is as bright as possible.
If I'm focusing with LiveView through the laptop, I'll zoom into 5x mode and set 200% display, and then use the operating system's accessibility tool to digitally zoom in even further so that the star almost fills the monitor. This lets me judge the focus from several metres away.
An even easier approach is to get software to make focus adjustments and check it for you automatically - e.g. Backyard EOS can give FWHM feedback in real time.
I took a chance and imaged comet Lovejoy again this morning after taking a break on the 30th. Boy, has it dimmed! I could just about make it out naked eye and averted vision was needed to see the extend of the tail.
I took lots of images but half was lost since I must have bumped the focus ring at one stage.
This is the first image of the set which I've been able to process to a degree where I'm reasonably happy with it. Still struggling to get the colors right.
Thanks for the tip Theo. I tried messing around with IRIS but couldn't get the image to my satisfaction. I think the mountain at the bottom throws things off.
I did manage to get a reasonably good image from another set of shots I took .
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