Saturday, March 19, 2011

Moon photo for Super Moon Day

Today is not just any full moon, its a super full moon!

Well to be precise it's a full moon when it is also at its perigee i.e. nearest point to the Earth, and hence is just slightly bigger than normal. It is not actually the nearest so don't fear Hollywood style destruction, as it will be closer still in 2016.

The above photo was taken yesterday when the moon was nearly but not quite exactly full. It's also not quite as sharp as I'd like and I'm wondering why. I tried getting the exposure time down to reduce motion blur, but that didn't help so I'm wondering if its a sign of weakness in the lens.

Its a rather cheap and cheerful 70 - 300 mm Canon lens, the bottom of their range, and with a new 18 megapixel camera that is likely to be the weakest point. So I have been checking out options on and as always the best lenses are the most expensive and heavy, which is not helpful.

One question I'm not sure on is whether it would be better to go for a higher quality lens at 200 mm or a not quite so good lens at 300 mm - any suggestions? I really do not want anything too big or heavy - or silly expensive.


O Docker said...

Looks like it might be a touch of vibration blur, JP.

That becomes more of a factor at high magnifications. Some things to check:

- Use self-timer to release shutter to avoid touching camera at time of exposure.

- Try locking up the mirror if camera allows that

- Make sure tripod is on solid footing - i.e. if on a balcony or deck, your motion nearby could induce some shake.

- Wind can shake the camera enough to cause blur

This might also be slight focus error - this is a difficult task for autofocus. Try experimenting with manual focus. Also, the lens might be sharper stopped down a stop or two from wide open.

You're probably better off with a lesser lens at 300, than magnifying the image from a better quality 200.

I have the Nikon consumer grade 70-300 and, frankly, it's not very good past about 200. If you're doing a lot of this kind of photography, you might consider one of the slower fixed focal length 300, 400, or 500 lenses available, but avoid the mirror lenses which generally aren't as sharp as conventional glass (although there are some expensive exceptions).

Good luck.

JP said...

Thanks for that O'Docker, it could well be vibration blur. I have a mini tripod but its pretty bad so tend to try to wedge camera against something solid like the balcony railings rather than using it.

I've been a bit put off tripods as have found them either heavy to carry around or rather ineffectual, but it might be worth looking into that again - there might be some new ones out there.

If I had one then could use it with the self-timer. I've recently got the Canon 550 which I think does have mirror lock but haven't got that far in the user guide!

I need one longish lens for wildlife, sailing and astronomy so might get the next level up Canon 70-300 with IS but not L-series which are both too expensive and heavy (and often large).

JP said...

Ok, so have gone for the Canon EF 70-300mm f/4-5.6 IS USM lens plus one of those Joby Gorilla SLR tripods and thanks to the wonders of Amazon have already got it to hand.

Alas have not had time yet to play with it and the moon won't be up till post midnight.

Expect an update, just not sure when...