Go Back   Steve's Digicams Forums > Digital Cameras (Point and Shoot) > Canon

Reply
 
Thread Tools Search this Thread
Old Dec 14, 2011, 7:52 AM   #91
Senior Member
 
Slyfox's Avatar
 
Join Date: Mar 2009
Posts: 309
Default


Exposure 0.001 sec (1/800)
Aperture f/4.5
Focal Length 24.6 mm
ISO Speed 1600
Exposure Bias 0 EV
Flash Off, Did not fire

Slyfox is offline   Reply With Quote
Old Dec 14, 2011, 7:20 PM   #92
Member
 
Join Date: Dec 2006
Posts: 41
Default

I haven't thought about this much so please think a bit 'for me'.

One can get the blurred background effect when shooting using closeup lenses.. the bee photos prove this. And any magnifying glass in front
of a camera will let you get closeup photos along with the blurred
background.

However those , usually, only come in magnifications of +1, +2 and +3, +4 . They are just a magnifying glass attached to the camera.

But think:
What would the shots look like if a lower magnifying power were added
to a camera? Would we get the blurred background if you stepped back
from the subject and shot?


I have read up a little in a professional article about how professionals for the Stargate TV series had to use special lenses when they went from film to HD
in about 1996 to get blurred background shots. And the lenses were
physically very long.

What I didn't learn is whether the lenses are actually a style of magnification
lenses (1) so as to accomplish the same effect
if you put magnifying lenses on a camera,
get up very close, shoot, and get a blurred background (or even a partially
blurred image if the magnification is very high). The bee photos are a good
example of the effect one
gets when using a magnification lens where the subject itself can be partially
out of focus if the magnification is too high.


So what I am asking is:

Can we get a magnification lens, not a +1 but instead +0.1 or +0.3, etc?
(I'm assuming those would be the right nomenclature for less than +1
magnification).

Then try that to see if it helps to get blurred backgrounds?

When the articles I read mentioned the lengths of the lenses required for HD (versus film) they could have been attempting what I'm suggesting.

From my limited experience I can't see that trying out a sub-+1 magnifying
lens would require any special extra lenses.

If you have a friend who's an optometrist maybe you can spend an hour
with him .. and he'll let you shoot through the dozens or more of his
fixed lenses .. just set up the shot parameters first so you don't waste his
time.




If it were me I would do 1 of 2 things.

1. At a thrift store I'd offer to buy all of their eye glasses for 25c each .. talk to the highest level manager.. because no one has a use for old eyeglasses except an experimenter. Then try then to see if there's a focal point where you get a good focus
but out of focus background. That will only tell you that it's possible..

Using that lens will be too much work to adapt it to your camera. But then
if you have children they can enjoy playing with the lenses. I think I'd
soak them in hot soapy detergent and then a rinse of clorox


2. Post in a forum or talk to someone at B&H photo to ask what is used in professional HD work to accomplish the out of focus background then ask what you can do / use to make it work for yourself.

Surely there are articles on this problem but frankly in over 2 years I've
never seen them.

and last thing first:
Opening the iris / aperture all the way is the place to
begin.
And that's a manual setting.

There's probably several more that I'm unaware of .. but none would keep me from trying.

I'm sure there is a method to fix the problem because the problem can be fixed when one uses a closeup lens. For what it's worth you can do it
in software. In fact before 1999 there was software that caused anything
but the main subject to be of lower resolution so as to make the image
size smaller to save disk and web space. The effect causes everything but
the subject to be out of focus the more you tweak it.

When you find out something post it here for me. : ) Thanks.
I'm not that interested because most of my shots are technical (shooting machines)


(1) Pro lenses add many more intermediate lenses and that will make them
longer than is absolutely necessary to just get 'a shot' because of technical
worries about
other problems when lenses aren't just perfectly matched.

The problems of using only 1 lens in front of a camera are
a. color fringing where you get bad / wrong coloring at the edges of the photo
b. astigmatism (that's not the exact right word as applies to photos) where the photo
is out of focus in places it shouldn't be
c. glare / flare - where light comes in and ruins the shot because you've got a lens on the
end of the camera

Last edited by AndreLikesPhotos; Dec 14, 2011 at 7:44 PM. Reason: clarify
AndreLikesPhotos is offline   Reply With Quote
Old Dec 14, 2011, 8:01 PM   #93
Senior Member
 
Join Date: Sep 2011
Location: Bangor,North Wales
Posts: 3,741
Default

Quite simply- if you want a "not-so shallow" depth of field- step your aperture down a bit until you get the amount of depth you want-
See what difference going from f/2.7 to f/8 does- all else equal....
Attached Images
  
SIMON40 is offline   Reply With Quote
Old Dec 22, 2011, 8:40 PM   #94
Senior Member
 
Slyfox's Avatar
 
Join Date: Mar 2009
Posts: 309
Default

Slyfox is offline   Reply With Quote
Old Jan 2, 2012, 4:45 AM   #95
Junior Member
 
Join Date: Jan 2012
Posts: 1
Default

such a helpful topic for beginner user of sx40 thank you all!Please keep posting inspiring shots with sx40
archi88 is offline   Reply With Quote
Old Jan 2, 2012, 5:19 PM   #96
Senior Member
 
Slyfox's Avatar
 
Join Date: Mar 2009
Posts: 309
Default

Slyfox is offline   Reply With Quote
Old Jan 4, 2012, 7:49 PM   #97
Senior Member
 
Join Date: Sep 2011
Location: Bangor,North Wales
Posts: 3,741
Default

I just can't help myself....lol...
Attached Images
 
SIMON40 is offline   Reply With Quote
Old Jan 4, 2012, 9:00 PM   #98
Senior Member
 
Slyfox's Avatar
 
Join Date: Mar 2009
Posts: 309
Default

Quote:
Originally Posted by SIMON40 View Post
I just can't help myself....lol...
Beautiful





Slyfox is offline   Reply With Quote
Old Jan 5, 2012, 11:56 AM   #99
Junior Member
 
Join Date: Jan 2012
Posts: 1
Default

Quote:
Originally Posted by Slyfox View Post


Canon PowerShot SX40 HS
Exposure 0.008 sec (1/125)
Aperture f/5.8
Focal Length 150.5 mm
ISO Speed 200
Exposure Bias 0 EV
Flash Off, Did not fire
how do you get such a good Bokeh, also with so much zoom which mode you need to set to get F/5.8 if i zoom it doesnt go less than 8.
rikindshah is offline   Reply With Quote
Old Jan 5, 2012, 1:51 PM   #100
Senior Member
 
Join Date: Sep 2011
Location: Bangor,North Wales
Posts: 3,741
Default

hi rikindshah- if you switch to Aperture priority(AV) or Manual(M) mode you can select f/5.8 using the rear dial.
SIMON40 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 9:01 PM.