Go Back   Steve's Digicams Forums > Digicam Help > General Discussion

Reply
 
Thread Tools Search this Thread
Old Jan 30, 2004, 8:46 AM   #21
Senior Member
 
Join Date: Oct 2003
Posts: 3,652
Default

Quote:
if i can, i will get a pic of it for everyone
Gandalf065: YES!

Quote:
but i will be strong
GaR: Yeah, yeah, we've all said that. :twisted:
bcoultry is offline   Reply With Quote
Old Jan 30, 2004, 10:27 AM   #22
Administrator
 
Join Date: Jun 2003
Location: Savannah, GA (USA)
Posts: 22,378
Default

My latest camera is the Konica Revio KD-510z. It's also being sold as the Minolta DiMAGE G500. They are identical except for the Logo and Model Number.

This camera offers fixed focus choices, which you can have available under the 4-way controller keys.

Basically, you can customize the camera, so that only the focus choices you need appear when pressing the controller key. This allows you to quickly set focus, without using the menus.

I have mine setup to toggle between Autofocus, Macro Focus, 1m, 2m, 4m, and Landscape (infinity), when I press my right controller key.

Because of the great depth of field you get with this camera, you can easily estimate focus in total darkness.

For example: if taking a flash photo in total darkness, I can set focus to 2 meters.

At wide angle (8mm actual focal length of the lens, to get 39mm equivalent), this means that everything from 1.31 meters to 4.24 meters would be in focus (due to the great depth of field you'd have with this lens), using a wide open aperture of F2.8

This works out to everything in focus from about 4.3 feet to 13.9 feet in focus. This is likely where you'll be using the flash at anyway.

See this handy Depth of Field Calculator to get a better idea of how Focal Length, Distance to Subject, and Aperture impact focus.

You must use the actual (versus 35mm equivalent) focal length of the lens. For example: the lens on my Konica is 8mm - 24mm (in order to get an equivalent focal length range of 39mm-117mm).

So, plug in the Konica KD-500 (which uses the same lens and sensor as the Konica KD-510z and Minolta G500). Then plug in 8mm focal length, then plug in an aperture of F2.8 (what the camera will default to at wide angle), then plug in a distance to subject of 2 meters. Then calculate the results.

http://dfleming.ameranet.com/dofjs.html

If taking photos of something at a greater range in total darkness, I can then use 4 meters (available with a simple press of a controller key to toggle between fixed focus choices).

This would mean that everything from 1.94 meters (approx. 6.4 feet) to Infinity would be in focus at wide angle using F2.8 (what the camera will default to in darkness). I also have infinity as a focus choice (but it's not really needed at wide angle).

I can also switch to manual exposure mode if desired, and switch to a smaller aperture (higher F-Stop Number), for even greater depth of field.

Because the actual focal length of the lens in a consumer digital camera is much less than the equivalent focal length, you get tremendous depth of field.

This makes using fixed focus choices a very good option for getting sharply focused images in total darkness with my camera.
JimC is offline   Reply With Quote
Old Jan 30, 2004, 12:55 PM   #23
Junior Member
 
Join Date: Jan 2004
Posts: 17
Default

would i be right in thinking i could set say a point about 2 mtrs away from the camera and focus it in daylight and lock the focus, if i then took the picture in darkness with the camera in exactly the same place the picture would be in focus because i focused it before.

God bet that is wrong and ya all laffing at me

but hey least i will learn something

far to much to all this camera lark, point and click disposable cameras much better :P

GaR
garland is offline   Reply With Quote
Old Jan 30, 2004, 1:14 PM   #24
Administrator
 
Join Date: Jun 2003
Location: Savannah, GA (USA)
Posts: 22,378
Default

Quote:
Originally Posted by garland
would i be right in thinking i could set say a point about 2 mtrs away from the camera and focus it in daylight and lock the focus, if i then took the picture in darkness with the camera in exactly the same place the picture would be in focus because i focused it before.
far to much to all this camera lark, point and click disposable cameras much better :P
It depends on the camera. The problem is that you must make sure you are locking only the focus (not the focus and exposure).

My camera has separate focus lock and exposure lock features (allowing me to lock either one, or both for multiple exposures). Some cameras don't.

In any event, with my camera, I can simply use a manual focus choice of 2 meters in that situation. You don't need to be able to see anything at all with my camera to toggle between manual focus distance choices. This is not always true with other models.

Each camera will handle this type of thing differently. Some cameras have more manual focus options (and easier implementation) compared to others.

As for your disposable cameras, most of them are simply using a fixed focus lens. So, they are accomplishing the same thing as using a fixed focus choice on a camera like mine.

The problem is that you don't have a choice of focus points with a disposable camera, and you do with most cameras that are more advanced. So, you get sharper photos with a more flexible camera model (since you can tell it the focus point to use, based on the scene you are trying to capture).

Also, with a 35mm Disposable Camera, you're going to get far less depth of field for the same equivalent focal length (compared to a consumer digital camera). That's one of the reasons a disposable camera's photos will not enlarge very well (without looking blurry), unless you happen to be at the optimum distance from the camera for it's focus point.
JimC is offline   Reply With Quote
Old Jan 30, 2004, 1:34 PM   #25
Junior Member
 
Join Date: Jan 2004
Posts: 17
Default

wow you guys know so much love it keep it coming...

gonna get me a book or 2 MUST improve

GaR
garland is offline   Reply With Quote
Old Jan 30, 2004, 4:46 PM   #26
Senior Member
 
Join Date: Dec 2002
Posts: 5,803
Default

Quote:
gonna get me a book or 2 MUST improve
Interesting, I say the same thing regularly....

Eric
eric s is offline   Reply With Quote
Old Jan 30, 2004, 5:10 PM   #27
Senior Member
 
Join Date: Oct 2003
Posts: 3,652
Default

Quote:
gonna get me a book or 2 MUST improve
Quote:
Interesting, I say the same thing regularly....
Yes, and it's getting darned expensive, too! However, when it comes to straight photography books, if a library near you has periodic fund-raising book sales, go to them. I've amassed quite a collection of traditional photo books, all of which cost no more than 50 cents each. Since it doesn't matter what kind of camera you're using when it comes to the elements of photography, it also doesn't matter if the book is referring to film cameras.
bcoultry is offline   Reply With Quote
Old Jan 30, 2004, 11:20 PM   #28
Senior Member
 
Join Date: Dec 2002
Posts: 5,803
Default

Our local library network is on the net, which covers about... 30 libraries. Whenever I see someone suggest a book, I check to see one of the participating libraries has it. They usually don't, but I'm surprised every now and then. Now I just have to setup network reservations and I'll be all set!

Eric
eric s is offline   Reply With Quote
Old Jan 31, 2004, 3:04 PM   #29
Senior Member
 
Join Date: Oct 2003
Posts: 3,652
Default

Quote:
Originally Posted by eric s
Our local library network is on the net, which covers about... 30 libraries. Whenever I see someone suggest a book, I check to see one of the participating libraries has it. They usually don't, but I'm surprised every now and then. Now I just have to setup network reservations and I'll be all set!
Yes, I imagine it's that way all across the country now. It's really nice when at least one decent-sized city is included in the system, which is what I have here--only it's 3 cities. Still, though, I love going to the library where I can touch the books and maybe discover those I wouldn't have thought of otherwise. We have online reservation and notification, and it's definitely great for ordering books from distant libraries.
bcoultry is offline   Reply With Quote
Old Jan 31, 2004, 4:45 PM   #30
Senior Member
 
Join Date: Aug 2002
Posts: 2,162
Default

JimC - when I referred to distance readout earlier, I was thinking of my Minolta S414. It sounds from your post that this might just be a Minolta thing. I know for a wide angle setting, I only have to choose a couple of distance settings - near and far basically, until I start using zoom.

A comment on the question of focusing in daylight - most cameras lose any focus setting when they are turned off and back on. There were many posts about the Fuji 602 and 'finding infinity'. This question arose because manual focus through the low res. EVF was not very accurate, and when the camera is switched on it always defaults to near focus (when you might have thought infinity would be more useful). Near focus is also the default when AF fails to lock. The fact that you can turn the focus ring like an slr is handy, BUT it rotates continuously with no end stops, so there's no easy way to find infinity except rotate untill the stepper motor stops (beyond infinity) then 'back a bit' - which is very hit and miss.

Another thing I've found when shooting at night, is if you can't see much, then apart from the obvious problem of framing, it's worth finding out when using an optional optical viewfinder, if there any key functions that still need the lcd and I'd put focus distance in this category. On the 414, Minolta came up with the great idea of the second alphanumeric only display (very low power), Unfortunately they didn't put focus distance on it, included flash modes, but then didn't backlight it!. Cheers VOX
voxmagna is offline   Reply With Quote
 
Reply


Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off



All times are GMT -5. The time now is 2:10 PM.