Need help on Northern Lights

[edalaska]

Hi All, I've been having bad luck with shooting the Aurora Borealis with the Canon Digital Rebel. Have tried shooting at f/1.4 @ asa 400 for 4-30 seconds on a sturdy tripod. The backround stars and tree line in the distance are always out of focus, as are the Auroras. Manual focus at night is a challenge so I even tried autofocus just before night and using that setting. Predictably, results were out-of-focus. Pictures shot side-by-side with a Minolta Maxxum 9000 film camera give good results. Does anyone have ideas as to what I'm doing wrong with the EOS? Any help would be greatly appreciated! Happy New Year.

[Curtis N]

I'm not sure if this is the best method, but when I have done star trails in the past, I autofocus on the moon, then switch the lens to manual focus so it stays there.

Keep in mind that with a 30 second exposure, the stars might move enough that they appear to be OOF.

[edalaska]

Thanks for your help Curtis. I'll try that when we have Auroras and a moon that is not too bright to wash them out. Ed

[PhotosGuy]

I autofocus on the moon, then switch the lens to manual focus so it stays there.
Keep in mind that with a 30 second exposure, the stars might move enough that they appear to be OOF.

With the 50mm, I'd think you should be able to MF on the stars? Or something in the distance during the day? Then tape the focus ring so that you don't bump it.
Any aurora I've seen is constantly pulsing, so that might cause it to look OOF, too.

[bolantej]

i would try a faster shutter speed just to be sure, even if it means bumping up the ISO. I'd love to see the Northern Lights in person one day.

[Mark_Cohran]

I would think the aurora would be far enough away that you could simply manually focus to infinity and be done with it.

Mark

[edalaska]

Thanks everyone for writing back! Haven't logged on in a couple days so I'll try to respond to everyone. Sorry if this is bad form, but I'm new to the forum.

Hello Mark, the EF USM and IS Canon lenses that I shoot with have settings slightly past infinity to compensate for changes in temperature. For infinite focus at normal temperatures, whatever normal may be, +70 I guess, manual focus is dead on the vertical line, but temps here on clear winter nights can be -35 F. Setting the infinity focus on the Minolta Maxxum with AF lens works fine by just twisting it to the end regardless of temperature. Just guessing, but I think temperature may be the issue here.

Hi Frank, I've tried autofocus just before dark and taping the lens at that point, but possibly the falling temperatures cause slight distortion within the lens elements that alter focus. Also have tried leaving the camera out for a while before shooting to equalize its temp with the outdoors, the same as one does with telescopes for best imagery. For whatever it's worth, there is nothing light around home to autofocus on at infinity at night. The stars are extremely bright and look in focus to me at a range of settings. Sometimes the Auroras are dim and-or almost motionless so a 10-20 second shot builds up image. Other times they are extremely bright and move so rapidly any shot longer than a second can produce blurred images. That variation produces the learning curve for me.

Hi to you too, Bolantej. Side-by-side shooting with the Minolta at ISO 400 has produced very nice photos with no graininess and sharp star images. I was concerned about grain at higher ISO, but will try faster shutter speed and higher ISO. Maybe I have a bad 50 mm f/1.4 USM. I may stop it down a little or just try another lens next time for a point of comparison. Thanks again to everyone for all the help and suggestions. Ed

[hugeknot]

Hey what lens are you using? It could just be that f/1.4 is not so sharp. I have the 24mm f/1.4 and I have only used f/1.4 once or twice as usually f/2.8 will do.

As for focusing in the field. I have never experienced temperature fluctuations as you describe. Although temperatures rarely drop below -20 here. I would suggest using the furthest light you can find and stopping down a little to increase DOF. Or, you could calibrate your lens during the day at similar temperatures.

[Karl Johnston]

Set focus to infinity, stars should be sharp at even 1.4, have seen some extremely sharp shots done with the 50 1.4 for aurora and astrophotography.

Not sure why it would be OOF if the focus is set manually to infinity and kept there. Try to use LV mode to focus extra close (if you have that, not sure what kind of EOS you are using..)

Try this guide
http://photography-on-the.net/forum/...d.php?t=764500

and check out some aurora shots of mine I would love to take a look at some of yours when you have them up! be sure to post some results.
http://www.synergystudiosphotography.com/fine-art/

I can't relate on the temperature issue, we have had them out in -40 to -55C for prolonged use and not problems even when going in from hot to cold. Maybe the 50 1.4 needs to be calibrated? On the 50D and above you can do this but I think you may need to send them out to canon HQ to be calibrated if not. Not sure but I haven't heard of temperature affecting lenses like that. Try moving the manual focus all the way past the infinity line - sometimes for certain lenses you need to do that otherwise it won't truly be at infinity.

Auroras being blurry ? Can you post a sample pic please?

[Mark_Cohran]

You guys realize the OP posted this nearly 3 years ago, right?

[Karl Johnston]

Had no idea. LOL wow...good one hugeknot :P

Temps in iceland only go to -20 Oh right..greeland is the cold one..I keep mixing them up I need to check out iceland..looks beautiful from your link

[JerelXTI]

Originally Posted by edalaska

Thanks everyone for writing back! Haven't logged on in a couple days so I'll try to respond to everyone. Sorry if this is bad form, but I'm new to the forum.

Hello Mark, the EF USM and IS Canon lenses that I shoot with have settings slightly past infinity to compensate for changes in temperature. For infinite focus at normal temperatures, whatever normal may be, +70 I guess, manual focus is dead on the vertical line, but temps here on clear winter nights can be -35 F. Setting the infinity focus on the Minolta Maxxum with AF lens works fine by just twisting it to the end regardless of temperature. Just guessing, but I think temperature may be the issue here.

Hi Frank, I've tried autofocus just before dark and taping the lens at that point, but possibly the falling temperatures cause slight distortion within the lens elements that alter focus. Also have tried leaving the camera out for a while before shooting to equalize its temp with the outdoors, the same as one does with telescopes for best imagery. For whatever it's worth, there is nothing light around home to autofocus on at infinity at night. The stars are extremely bright and look in focus to me at a range of settings. Sometimes the Auroras are dim and-or almost motionless so a 10-20 second shot builds up image. Other times they are extremely bright and move so rapidly any shot longer than a second can produce blurred images. That variation produces the learning curve for me.

Hi to you too, Bolantej. Side-by-side shooting with the Minolta at ISO 400 has produced very nice photos with no graininess and sharp star images. I was concerned about grain at higher ISO, but will try faster shutter speed and higher ISO. Maybe I have a bad 50 mm f/1.4 USM. I may stop it down a little or just try another lens next time for a point of comparison. Thanks again to everyone for all the help and suggestions. Ed

Hi Edalaska, I'm Stationed in fairbanks. I too have not had any luck with the northern lights. I will keep trying. Good luck

[number six]

Originally Posted by Mark_Cohran

You guys realize the OP posted this nearly 3 years ago, right?

Four, actually.

[Veemac]

Originally Posted by Mark_Cohran

You guys realize the OP posted this nearly 3 years ago, right?

I didn't notice as I first started reading it, but I did immediately think to myself that I hoped Karl would weigh in on the question sooner or later!