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Focus in low/no light, also what about ultrasonic?

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Josh Carmack

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Some people have issues with the autofocus on the camera, is it my cheap lens decision, or is the camera just not going to focus good when there isn't enough contrast in the image.

Example, i was standing on top of an unaccessable(no on/off ramps) overpass to an interstate at night. I was wanting to do some lighting effects with a slow exposure and the tailights of the underpassing cars.

My flashlight hadn't been charged so it was useless. The camera wouldn't focus even with flash assist. so I wound up manually focusing with the light of passing cars. my images turned out much softer than I wanted.

I went back later with a charged flashlight, but it wasnt enought for me or the camera to focus. (the flashlight is actaully a cordless 2,000,000 candle power spotlight, about as bright as they come) The asphalt was to dark for enough reflection me me to focus. I wound up getting some more soft images.

I can't focus in twilight and then wait, as the sherriff dept informed me not to stay there longer than 20 minutes, because they already recieved two calls from people who thought i was a sniper taking shots.
Suggestions???
--
Can't see the forest for the trees. (Or is it the lens?)
See my personal website at http://www.ccsnmore.com
 
Ummm...Josh...2,000,00 candle power spotlight into the eyes of oncoming traffic? You'll be lucky if they dont snipe you!! I recommend a new subject unless you really want photos of a car accident.
Josh Carmack said:
Some people have issues with the autofocus on the camera, is it my
cheap lens decision, or is the camera just not going to focus good
when there isn't enough contrast in the image.

Example, i was standing on top of an unaccessable(no on/off ramps)
overpass to an interstate at night. I was wanting to do some
lighting effects with a slow exposure and the tailights of the
underpassing cars.
My flashlight hadn't been charged so it was useless. The camera
wouldn't focus even with flash assist. so I wound up manually
focusing with the light of passing cars. my images turned out much
softer than I wanted.
I went back later with a charged flashlight, but it wasnt enought
for me or the camera to focus. (the flashlight is actaully a
cordless 2,000,000 candle power spotlight, about as bright as they
come) The asphalt was to dark for enough reflection me me to focus.
I wound up getting some more soft images.
I can't focus in twilight and then wait, as the sherriff dept
informed me not to stay there longer than 20 minutes, because they
already recieved two calls from people who thought i was a sniper
taking shots.
Suggestions???
--
Can't see the forest for the trees. (Or is it the lens?)
See my personal website at http://www.ccsnmore.com
Click to expand...
--
http://www.pbase.com/patricstandley/the_flowers_of_hawaii
 
My backup camera (Sony DSC-V1) has night framing w/ laser assist. This frames the pic in your viewfinder (LCD in this case) in night vision, fires a laser pattern and meters off of the laser range to determine proper preflash.. Works quite well within 10 meters. Nice technology I think, and its a small camera so It stays in my bag as a backup.
Patric Standley said:
Josh Carmack said:
Some people have issues with the autofocus on the camera, is it my
cheap lens decision, or is the camera just not going to focus good
when there isn't enough contrast in the image.

Example, i was standing on top of an unaccessable(no on/off ramps)
overpass to an interstate at night. I was wanting to do some
lighting effects with a slow exposure and the tailights of the
underpassing cars.
My flashlight hadn't been charged so it was useless. The camera
wouldn't focus even with flash assist. so I wound up manually
focusing with the light of passing cars. my images turned out much
softer than I wanted.
I went back later with a charged flashlight, but it wasnt enought
for me or the camera to focus. (the flashlight is actaully a
cordless 2,000,000 candle power spotlight, about as bright as they
come) The asphalt was to dark for enough reflection me me to focus.
I wound up getting some more soft images.
I can't focus in twilight and then wait, as the sherriff dept
informed me not to stay there longer than 20 minutes, because they
already recieved two calls from people who thought i was a sniper
taking shots.
Suggestions???
--
Can't see the forest for the trees. (Or is it the lens?)
See my personal website at http://www.ccsnmore.com
Click to expand...
--
http://www.pbase.com/patricstandley/the_flowers_of_hawaii
Click to expand...
--
http://www.pbase.com/patricstandley/the_flowers_of_hawaii
 
Perhaps try a cheap laser pointer? Having said that, don't go pointing it in traffic obviously. Wait for a break in traffic if you're lucky enough, point it in the middle of your framing/composition and focus with a half depression of the shutter. Lock your focus and press the shutter once the traffic comes through.

Worth a go?

Craig H
:)
Josh Carmack said:
Some people have issues with the autofocus on the camera, is it my
cheap lens decision, or is the camera just not going to focus good
when there isn't enough contrast in the image.

Example, i was standing on top of an unaccessable(no on/off ramps)
overpass to an interstate at night. I was wanting to do some
lighting effects with a slow exposure and the tailights of the
underpassing cars.
My flashlight hadn't been charged so it was useless. The camera
wouldn't focus even with flash assist. so I wound up manually
focusing with the light of passing cars. my images turned out much
softer than I wanted.
I went back later with a charged flashlight, but it wasnt enought
for me or the camera to focus. (the flashlight is actaully a
cordless 2,000,000 candle power spotlight, about as bright as they
come) The asphalt was to dark for enough reflection me me to focus.
I wound up getting some more soft images.
I can't focus in twilight and then wait, as the sherriff dept
informed me not to stay there longer than 20 minutes, because they
already recieved two calls from people who thought i was a sniper
taking shots.
Suggestions???
--
Can't see the forest for the trees. (Or is it the lens?)
See my personal website at http://www.ccsnmore.com
Click to expand...
 
I was shining it when ther was no traffic...ohh my yeah, i'm sure that would have been something no no, its I-10 east of mobile, traffic is quite light, often minutes between cars.
Patric Standley said:
Josh Carmack said:
Some people have issues with the autofocus on the camera, is it my
cheap lens decision, or is the camera just not going to focus good
when there isn't enough contrast in the image.

Example, i was standing on top of an unaccessable(no on/off ramps)
overpass to an interstate at night. I was wanting to do some
lighting effects with a slow exposure and the tailights of the
underpassing cars.
My flashlight hadn't been charged so it was useless. The camera
wouldn't focus even with flash assist. so I wound up manually
focusing with the light of passing cars. my images turned out much
softer than I wanted.
I went back later with a charged flashlight, but it wasnt enought
for me or the camera to focus. (the flashlight is actaully a
cordless 2,000,000 candle power spotlight, about as bright as they
come) The asphalt was to dark for enough reflection me me to focus.
I wound up getting some more soft images.
I can't focus in twilight and then wait, as the sherriff dept
informed me not to stay there longer than 20 minutes, because they
already recieved two calls from people who thought i was a sniper
taking shots.
Suggestions???
--
Can't see the forest for the trees. (Or is it the lens?)
See my personal website at http://www.ccsnmore.com
Click to expand...
--
http://www.pbase.com/patricstandley/the_flowers_of_hawaii
Click to expand...
--
Can't see the forest for the trees. (Or is it the lens?)
See my personal website at http://www.ccsnmore.com
 
Josh Carmack said:
I can't focus in twilight and then wait, as the sherriff dept
informed me not to stay there longer than 20 minutes, because they
already recieved two calls from people who thought i was a sniper
taking shots.
Click to expand...
Hi

You could try setting a small aperture to ensure large DOF, and then manually focus on infinity.

You can practice this in daylight - basically wind the focus all the way round and then back off ever so slightly.

Steve
 
The only way to improve the focussing ability is to use a fast lens.

Something like the 50mm F1.8 might be worth trying.

USM lenses focus faster and more quietly, but the don't focus any better in low light than non USM lenses.

Steve
 
Those keychain laser pointers sold on EBay for a few bucks (after shipping) come with multiple heads besides just a dot. UFOs, peace signs etc. That should give you a larger target at that distance and work similar to the low light assist on good external flashes. ~ m²
Craig H said:
Perhaps try a cheap laser pointer?
Click to expand...
--

If alcohol kills brain cells, then the process of natural selection will thin the 'herd' by eradicating the slowest & weakest... thus making me smarter! - Cliff Claven's 'Buffalo Theory' http://rhodeymark.instantlogic.com

 
focus at daytime, remeber the setting (put it in MF and don't touch it no more) and then use it at night.
Josh Carmack said:
Some people have issues with the autofocus on the camera, is it my
cheap lens decision, or is the camera just not going to focus good
when there isn't enough contrast in the image.

Example, i was standing on top of an unaccessable(no on/off ramps)
overpass to an interstate at night. I was wanting to do some
lighting effects with a slow exposure and the tailights of the
underpassing cars.
My flashlight hadn't been charged so it was useless. The camera
wouldn't focus even with flash assist. so I wound up manually
focusing with the light of passing cars. my images turned out much
softer than I wanted.
I went back later with a charged flashlight, but it wasnt enought
for me or the camera to focus. (the flashlight is actaully a
cordless 2,000,000 candle power spotlight, about as bright as they
come) The asphalt was to dark for enough reflection me me to focus.
I wound up getting some more soft images.
I can't focus in twilight and then wait, as the sherriff dept
informed me not to stay there longer than 20 minutes, because they
already recieved two calls from people who thought i was a sniper
taking shots.
Suggestions???
--
Can't see the forest for the trees. (Or is it the lens?)
See my personal website at http://www.ccsnmore.com
Click to expand...
 
I'm sorry for not being clear, i forgot to finish my message before i posted it. i meant to ask, what do people think about cameras that us ultra sonic pinging to focus, does anyone know of a DSLR that focuses ultra sonically, i dont figure there is, as it would have to be able to focus along the entire range of the lenses sold to mount on that particular camera. And considering the focal length of some lenses, the ultra sonic emmiter would have to be extreemly powerful.
Thoughts anyone?
Steve Lupton said:
The only way to improve the focussing ability is to use a fast lens.

Something like the 50mm F1.8 might be worth trying.

USM lenses focus faster and more quietly, but the don't focus any
better in low light than non USM lenses.

Steve
Click to expand...
--
Can't see the forest for the trees. (Or is it the lens?)
See my personal website at http://www.ccsnmore.com
 
Radar focus? That's certainly an intriguing concept. I think a laser rangefinder would work too, but there'd be that whole seared eyeball thing, which might be a product liability issue. I don't think there is anything extant, but you should get yourself to the USPTO forthwith! Maybe you could have a hybrid AF system that used current AF technology augmented with a distance finder. There could even be a confirmatory "distance to target" reading in the viewfinder. Seriously, I think this is a concept that could and should be pursued. Good on ya, mate!
Josh Carmack said:
I'm sorry for not being clear, i forgot to finish my message before
i posted it. i meant to ask, what do people think about cameras
that us ultra sonic pinging to focus, does anyone know of a DSLR
that focuses ultra sonically, i dont figure there is, as it would
have to be able to focus along the entire range of the lenses sold
to mount on that particular camera. And considering the focal
length of some lenses, the ultra sonic emmiter would have to be
extreemly powerful.
Thoughts anyone?
Click to expand...
 
The autofocus relies on contrast to establish proper focus. Any camera using this system will have trouble in low light or when there is nothing with any texture to focus on.
Josh Carmack said:
Some people have issues with the autofocus on the camera, is it my
cheap lens decision, or is the camera just not going to focus good
when there isn't enough contrast in the image.

Example, i was standing on top of an unaccessable(no on/off ramps)
overpass to an interstate at night. I was wanting to do some
lighting effects with a slow exposure and the tailights of the
underpassing cars.
My flashlight hadn't been charged so it was useless. The camera
wouldn't focus even with flash assist. so I wound up manually
focusing with the light of passing cars. my images turned out much
softer than I wanted.
I went back later with a charged flashlight, but it wasnt enought
for me or the camera to focus. (the flashlight is actaully a
cordless 2,000,000 candle power spotlight, about as bright as they
come) The asphalt was to dark for enough reflection me me to focus.
I wound up getting some more soft images.
I can't focus in twilight and then wait, as the sherriff dept
informed me not to stay there longer than 20 minutes, because they
already recieved two calls from people who thought i was a sniper
taking shots.
Suggestions???
--
Can't see the forest for the trees. (Or is it the lens?)
See my personal website at http://www.ccsnmore.com
Click to expand...
--
Michael Scott
http://www.pbase.com/kodack
http://kodacksdarkness.com

 
Well, if I did, i would be a day late, and a dollar short as far as the idea being a new idea, as there are already cameras that are in use that focus ultrasonically, I just dont think that any of the systems are inplemented on a SLR system.

Although i will research the idea of having it as an added feature like you mentioned, but once agian, its not a totally new concept, so i'm sure somone has beat me to the punch years ago. Thanks for the drive though.
alistairsyme said:
Josh Carmack said:
I'm sorry for not being clear, i forgot to finish my message before
i posted it. i meant to ask, what do people think about cameras
that us ultra sonic pinging to focus, does anyone know of a DSLR
that focuses ultra sonically, i dont figure there is, as it would
have to be able to focus along the entire range of the lenses sold
to mount on that particular camera. And considering the focal
length of some lenses, the ultra sonic emmiter would have to be
extreemly powerful.
Thoughts anyone?
Click to expand...
Click to expand...
--
Can't see the forest for the trees. (Or is it the lens?)
See my personal website at http://www.ccsnmore.com
 
Kodack said:
Josh Carmack said:
Some people have issues with the autofocus on the camera, is it my
cheap lens decision, or is the camera just not going to focus good
when there isn't enough contrast in the image.

Example, i was standing on top of an unaccessable(no on/off ramps)
overpass to an interstate at night. I was wanting to do some
lighting effects with a slow exposure and the tailights of the
underpassing cars.
My flashlight hadn't been charged so it was useless. The camera
wouldn't focus even with flash assist. so I wound up manually
focusing with the light of passing cars. my images turned out much
softer than I wanted.
I went back later with a charged flashlight, but it wasnt enought
for me or the camera to focus. (the flashlight is actaully a
cordless 2,000,000 candle power spotlight, about as bright as they
come) The asphalt was to dark for enough reflection me me to focus.
I wound up getting some more soft images.
I can't focus in twilight and then wait, as the sherriff dept
informed me not to stay there longer than 20 minutes, because they
already recieved two calls from people who thought i was a sniper
taking shots.
Suggestions???
--
Can't see the forest for the trees. (Or is it the lens?)
See my personal website at http://www.ccsnmore.com
Click to expand...
--
Michael Scott
http://www.pbase.com/kodack
http://kodacksdarkness.com

Click to expand...
--
Can't see the forest for the trees. (Or is it the lens?)
See my personal website at http://www.ccsnmore.com
 
Kodack said:
Josh Carmack said:
Some people have issues with the autofocus on the camera, is it my
cheap lens decision, or is the camera just not going to focus good
when there isn't enough contrast in the image.

Example, i was standing on top of an unaccessable(no on/off ramps)
overpass to an interstate at night. I was wanting to do some
lighting effects with a slow exposure and the tailights of the
underpassing cars.
My flashlight hadn't been charged so it was useless. The camera
wouldn't focus even with flash assist. so I wound up manually
focusing with the light of passing cars. my images turned out much
softer than I wanted.
I went back later with a charged flashlight, but it wasnt enought
for me or the camera to focus. (the flashlight is actaully a
cordless 2,000,000 candle power spotlight, about as bright as they
come) The asphalt was to dark for enough reflection me me to focus.
I wound up getting some more soft images.
I can't focus in twilight and then wait, as the sherriff dept
informed me not to stay there longer than 20 minutes, because they
already recieved two calls from people who thought i was a sniper
taking shots.
Suggestions???
--
Can't see the forest for the trees. (Or is it the lens?)
See my personal website at http://www.ccsnmore.com
Click to expand...
--
Michael Scott
http://www.pbase.com/kodack
http://kodacksdarkness.com

Click to expand...
--

 
Josh, if you could find a camera that does focus ultrasonically (digital or film, DSLR or P&S), I would be very interested if you could post a link. Thanks!
Josh Carmack said:
alistairsyme said:
Josh Carmack said:
I'm sorry for not being clear, i forgot to finish my message before
i posted it. i meant to ask, what do people think about cameras
that us ultra sonic pinging to focus, does anyone know of a DSLR
that focuses ultra sonically, i dont figure there is, as it would
have to be able to focus along the entire range of the lenses sold
to mount on that particular camera. And considering the focal
length of some lenses, the ultra sonic emmiter would have to be
extreemly powerful.
Thoughts anyone?
Click to expand...
Click to expand...
--
Can't see the forest for the trees. (Or is it the lens?)
See my personal website at http://www.ccsnmore.com
Click to expand...
 
I'm wondering why the Rebel doesn't have an AF assist lamp. Is it a scheme for selling flashes? I've had many situations when I have enough light for an exposure, but simply can't get a focus lock. I'm realizing I need to buy a 550EX even though I won't actually be using the flash most of the time. That seems silly. That is probably the most glaring omission, but even the 1D and 10D lack one. My boss' D100 has one, but it's an obnoxious white LED. The red LED on my friend's flash allows me to get lock in the most dodgy of circumstances. Why isn't it on the body?
 
I can't to think of any offhand, but there were some cameras that used to used ultrasonic focusing. I'm guessing it wasn't anything like the focussing systems used on todays cameras. I haven't seen any here recently that utilized that type of system. I honestloy dont know of any cameras that use it, I have just read it in several publications that certian camera's used sound as a focussing method.

I will see what i can find though. I'll post the links back to this thread. Keep checking back, if i dont find anything in the next few days, I'll let you know.
alistairsyme said:
Josh Carmack said:
alistairsyme said:
Josh Carmack said:
I'm sorry for not being clear, i forgot to finish my message before
i posted it. i meant to ask, what do people think about cameras
that us ultra sonic pinging to focus, does anyone know of a DSLR
that focuses ultra sonically, i dont figure there is, as it would
have to be able to focus along the entire range of the lenses sold
to mount on that particular camera. And considering the focal
length of some lenses, the ultra sonic emmiter would have to be
extreemly powerful.
Thoughts anyone?
Click to expand...
Click to expand...
--
Can't see the forest for the trees. (Or is it the lens?)
See my personal website at http://www.ccsnmore.com
Click to expand...
Click to expand...
--
Can't see the forest for the trees. (Or is it the lens?)
See my personal website at http://www.ccsnmore.com
 
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