Night time focusing

[Jonny]

Hi guys,

Last night i tried my hand at my first Sunset/night photography and have a question for you all. How do you focus?
The pic below is a sample from last night and as you can see the foreground focus is way out. The exposure was 30 seconds and it was really dark and i found it real hard to focus on the trees, so i just set the focus to infinity and hoped for the best.

How do you do it?

http://homepage.ntlworld.com/j.speed/Forums%20Pictures/sunset.jpg

[blinking8s]

well, what apature and focal length were you at? you can calculate your depth of field and then focus from there...

infinity isnt infinity if your dop doesnt reach infinity...hehe...whoa :shock:

[Jonny]

Hi,

Ok, this pic was 28mm @f/9, iso 400, 30 secs.

Any help on how to calculate would be great, many thanks

Jon

[c0ntr0lz]

yeah spread that think way out, and it'll look nice

[sGu]

in lowlight, try manual focus, auto focus will find hard time lock on the right object, it'll just zoom in and out constantly searching for it.

Also there is a great feature within 1D which have been underrated, the DEP mode. From the name, you can tell it's depth-of-field. What it does, you frame you shot, set focal length on your lens, then use centre point to take a reading of furthest focus point and then take a reading of closest focus point, camera will then calculate the aperture for maximum depth of field for you.

unfortunately this feature was forgotten in MK II.

[jobe]

Try this explanation of hyperfocal distance and a chart to calculate the focal distance.
Hope it helps

http://www.vividlight.com/articles/3513.htm

[ssim]

30 second exposure time seems like forever when you are waiting for the shutter to close. Keep in mind that with an exposure of this length that even the slightest wind movement will make your trees and clouds soft. It can also produce movement of the camera on a tripod even though you may think it is solid.

I always try to keep the exposure time around 5 seconds if possible.

On a subject like this I would also manually foucs.

[neil_r]

30 second exposure time seems like forever when you are waiting for the shutter to close. Keep in mind that with an exposure of this length that even the slightest wind movement will make your trees and clouds soft. It can also produce movement of the camera on a tripod even though you may think it is solid.

I always try to keep the exposure time around 5 seconds if possible.



I beg to differ, the longer the exposure the less effect any movement will have. I regularly use exposures of over 20 seconds with no problems, I now that I have posted this b4 but it is a fair ilistration as it was taken with an exposure of 21 seconds @ f11 100 ISO.

http://www.neil-rice.com/gallery/photo/large/newcastle_28_7_04_0065a.jpg

N

[flowe]

HFD and DOF strictly depend on the current focal length of the lens - but, with a Canon G camera, there is no way to know this (apart from min/max). For the technically minded owner of a G or similar camera, there is a solution with in depth threatment of HFD and DOF and specific tables at this site (http://homepage.hispeed.ch/flowe/digifoto/hfd_dof.htm)

[ssim]

30 second exposure time seems like forever when you are waiting for the shutter to close. Keep in mind that with an exposure of this length that even the slightest wind movement will make your trees and clouds soft. It can also produce movement of the camera on a tripod even though you may think it is solid.

I always try to keep the exposure time around 5 seconds if possible.



I beg to differ, the longer the exposure the less effect any movement will have. I regularly use exposures of over 20 seconds with no problems, I now that I have posted this b4 but it is a fair ilistration as it was taken with an exposure of 21 seconds @ f11 100 ISO.

N

Well Neil I guess that we will agree to disagree. You have an awesome image there. If you notice in your image you have absolute dead still water with nothing that could/would be moved by wind. There are not any clouds in your image to indicate movement on a longer exposure.

In the image that was posted on the original question does have elements in it that could become soft due to movement as a result of a long exposure. In particular the clouds and the trees. What I said is that wind can create softness in an image. I didn't say that it did in this case as none of us were there.

[neil_r]

Well Neil I guess that we will agree to disagree.

Now that is why I really like this forum. :lol:

A point about the water in my shot, you are right there was no wind but the Tyne is tidal and the water was moving at quite a lick towards me, but I do take your point that prolonged movement can soften the image.

An interesting and related story....

I was once in the Gaudy museum in Barcelona. It was full of people and a friend of mine was snapping away using his flash, when we later compared pictures he asked me when I had taken mine as there were no people in my shots and his were full of them. He did not believe me when I told him that I has simply put my camera on the top of an exhibition case and the shutter was open for over 30 seconds, this made the moving people disappear

N

[Jonny]

I just wish i could agree or disagree...im just lost :?