Lightning and a question

mushy · February 21, 2006

Took these last night from Kings Park overlooking the city (Perth, Western Australia)

Quick question for those in the know, is it just a case of to wide an apeture in these shots causing the city lights to look slightly blurred or am i missing something.
Comments welcomed
f5.6
iso 100
30 sec exposure

wxwax · February 21, 2006

Lovely stuff.

I'm thinking there was a breeze or vibration that moved your camera ever so slightly.

Bob&Glennie · February 22, 2006

Your lens might be a wee bit soft open wide but you should be able to sharpen your pics with Unsharp Mask.

mushy · February 22, 2006

cheers for your thoughts but unfortunately this is already after USM, but with there already being slight halo's on everything with a light on it, USM seemed to almost make the situation worse.

Will also try a more heavy duty tripod next time.

gus · February 22, 2006

Dont bother with a heavier tripod it it wasnt windy.

Which lens was it ?

It must have been really dark to sit at 30 sec for f/5.6 ISO 100

I assume it was the kit lens which i adore for lightning...never a problem with it. Did you prefocus on one of those far off lights & then immediately switch the lens to manual ? It will hunt something terrible otherwise & i would expect this result from leaving the lens on auto in that much darkness.

mushy · February 22, 2006

Humungus wrote:

Dont bother with a heavier tripod it it wasnt windy.

Which lens was it ?

It must have been really dark to sit at 30 sec for f/5.6 ISO 100

I assume it was the kit lens which i adore for lightning...never a problem with it. Did you prefocus on one of those far off lights & then immediately switch the lens to manual ? It will hunt something terrible otherwise & i would expect this result from leaving the lens on auto in that much darkness.

The lens was 17-85mm IS USM and focused to infinity (MF), I'm tending now towards maybe just dropping the shutter speed next time to maybe 10seconds per shot. Will have to do some experimenting next clear night.

gus · February 22, 2006

mushy wrote:

and focused to infinity (MF),

There is your problem right there...the dreaded infinity focus. The lens goes slightly past infinity when you do this.

Next time use auto focus to lock onto one of the furtherest lights...switch to manual & dont touch the focus at all from then on. Nothing wrong with 30 sec exposure in my book.

mushy · February 22, 2006

Humungus wrote:

There is your problem right there...the dreaded infinity focus. The lens goes slightly past infinity when you do this.

Next time use auto focus to lock onto one of the furtherest lights...switch to manual & dont touch the focus at all from then on. Nothing wrong with 30 sec exposure in my book.

thankyou thankyou thankyou, possibly more lightning tonight, will go try try again!!

Cheers for your words of wisdom, you are the master of all things lightning in my book.

gus · February 22, 2006

I think that was the first time i have ever helped anyone with a question....will be interesting to see how you go.

If no lightning tonight then re-shoot it anyway asap to make sure you have it down pat on the night.

Awais Yaqub · February 22, 2006

my complain is over exposure
i have read some lightning trigger will help in this situation
or f/8 and 30 seconds with infinity focus turn off the auto focus
beautifull city

gluwater · February 22, 2006

Did you have IS turned on or off? If you have your camera on a tri-pod and have IS turned on you can actually cause camera shake.

mushy · February 22, 2006

gluwater wrote:

Did you have IS turned on or off? If you have your camera on a tri-pod and have IS turned on you can actually cause camera shake.

Yup IS was turned on, another thing to try next time cheers Gluwater.

gluwater · February 23, 2006

Glad to help. Hope to see more shots like these from you in the future.

gus · February 23, 2006

Why are you guys fooling with IS & a tripod

Shay Stephens · February 23, 2006

The easy answer is that you are looking at aberrations that show up when using wide apertures. Use a smaller aperture. You will face more diffraction bluring (unless you are at the lens sweet spot) but at least the lights won't blob out. Instead they will have a nice looking star pattern, and more pronounced the smaller the aperture gets.

gus · February 23, 2006

Shay Stephens wrote:

The easy answer is that you are looking at aberrations that show up when using wide apertures. Use a smaller aperture. You will face more diffraction bluring (unless you are at the lens sweet spot) but at least the lights won't blob out. Instead they will have a nice looking star pattern, and more pronounced the smaller the aperture gets.

Shay you dont think this is oof due to manual infinity focus that they said they did ? IE focal point going past infinity (if you get my drift)

Shay Stephens · February 23, 2006

If the whole image is blurry, then yes. You typically can't trust the focus system to focus on point sources of light, since the contrst is not at peak on a point source when it is in focus but rather out of focus shows the greatest contrast from the halo it produces.

If the "blur" is limited to just the bright light source (which is what I thought I read, but you know me, reading is hard) then that would indicate wide aperture induced aberrations.

Humungus wrote:

Shay you dont think this is oof due to manual infinity focus that they said they did ? IE focal point going past infinity (if you get my drift)

gus · February 23, 2006

Here is another i have i had to dig up from the challenges (no idea where the original is) i thought it may have had sharp lights but now that i look at it ...its a bit ordinary.

It was shot at 10mm from memory. I still recon your photo was unfocused...thats my call anyway.

Thusie · February 23, 2006

Humungus wrote:

Here is another i have i had to dig up from the challenges (no idea where the original is) i thought it may have had sharp lights but now that i look at it ...its a bit ordinary.

Not to hijack this very interesting thread, but I'll take your ordinary anyday.

mushy · February 23, 2006

well I've followed everybody's excellent advice and input and spent some time last night going through different exposures with different f-stops.
No IS !
Let Auto focus do its job then switch to manual
etc etc etc

and have come up with ISO 100, 15 sec exposure at f8 comes back with a pretty decent shot for a fairly bright city photo. I think anyways

Thank you all for your input any extra comments on the following picture are still welcomed of curse.

Shay Stephens · February 23, 2006

Just be careful of autofocus when your target is lights in a sea of black. It's hard for the system to tell when a point source of light is in focus.

mushy wrote:

Let Auto focus do its job

gus · February 23, 2006

Shay Stephens wrote:

Just be careful of autofocus when your target is lights in a sea of black. It's hard for the system to tell when a point source of light is in focus.

I use mars on some nights if its in the sky & it is a very dim light in an area as black as a bats arse

Shay Stephens · February 24, 2006

You can get better results with a large planet because they have a non zero diameter. A star or light bulb from miles away will have a zero diameter that is hard to focus on. So my advice is to generally be careful, and verify the focus in those situations, because it's not a slam dunk to focus on point sources of light.

Humungus wrote:

I use mars on some nights if its in the sky & it is a very dim light in an area as black as a bats arse

wxwax · February 24, 2006

Zero diameter = pinpoint?

Shay Stephens · February 24, 2006

wxwax wrote:

Zero diameter = pinpoint?

That's the word I was looking for

thank you

mushy · February 24, 2006

Shay Stephens wrote:

That's the word I was looking for thank you

So if I can't neccessarily rely on autofocus and the viewfinder is a tough call to tell if a building etc is in focus from several k's away is it just cross your fingers and hope your close enough for 'smart sharpen' or 'USM' to finish the job.

I guess I'm saying trial and error is the go yes??

gus · February 24, 2006

mushy wrote:

So if I can't neccessarily rely on autofocus and the viewfinder is a tough call to tell if a building etc is in focus from several k's away is it just cross your fingers and hope your close enough for 'smart sharpen' or 'USM' to finish the job.

I guess I'm saying trial and error is the go yes??

I always prefocus on auto & never get any issues at all.

Skippy · February 24, 2006

Wow

mushy wrote:

Took these last night from Kings Park overlooking the city (Perth, Western Australia)
Quick question for those in the know, is it just a case of to wide an apeture in these shots causing the city lights to look slightly blurred or am i missing something.
Comments welcomed
f5.6
iso 100
30 sec exposure

I say it again....... WOW ...... you lucky folks who live so close to big cities or have the ability to shoot across the water at cities and towns, I am jealous I tell you .... boy they look fantastic ... Skippy (Australia)

nokout3839 · February 24, 2006

Geelong

Skippy wrote:

I say it again....... WOW ...... you lucky folks who live so close to big cities or have the ability to shoot across the water at cities and towns, I am jealous I tell you .... boy they look fantastic ... Skippy (Australia)

Try the highton lookout, im not up in geelong anymore but if there is a storm that would be the place to get it.

Cheers, Nigel

Shay Stephens · February 24, 2006

Well if your lens has a distance readout, then take a look at it before shooting to give it a sanity check. Take photo and zoom in all the way to see if things look ok. Just don't focus on pinpoints of light and trust it blindly is all I am saying.

When all else fails, set the focus to infinity manually if that applies.

mushy wrote:

So if I can't neccessarily rely on autofocus and the viewfinder is a tough call to tell if a building etc is in focus from several k's away is it just cross your fingers and hope your close enough for 'smart sharpen' or 'USM' to finish the job.

I guess I'm saying trial and error is the go yes??