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Why are certain parts in focus?
- Thread starter sengngo
- Start date
slowhands214238
Veteran Member
They are in focus because that's the distance where the lens/camera was focused to, and, the foreground and background areas are "out of focus" because those are outside the Depth of Field created by the selection of distance and fStop
Or... someone used photoshop to blur the areas appearing to be out of focus
Or... someone used photoshop to blur the areas appearing to be out of focus
So how would I make it so that just the flower is in focus? Or do I have do some PP it to correct it? Thats the largest Aperture that Lens goes to so DOF can't be shallower unless I move back and then crop? I'm not sure I understand DOF. I thought DOF would more of a circle or oval around the focus point as opposed to the distance of the entire image.
sherwoodpete
Veteran Member
The lens focusses sharply on a flat plane at a specified distance. The depth of field gives the plane a bit of depth, rather than being paper-thin.
In the sample photo, the sharp parts are where that flat plane intersects the subject.
If you want the flower in focus but not the surroundings, the easiest solution is to arrange the subject so that nothing else in the frame is at the same distance as the flower. If that's not possible (as in the sample), PP is probably the answer.
Regards,
Peter
Thanks. Other than those ares being in focused is there anything else you can comment on the photo (it is mine). I've only had my D90 for two weeks so any constructive criticism is welcome.
RaymondR
Senior Member
Do yourself a favor -- read a basic book about photography or just the beginner guides provided on this website or others. Heck, the D90 manual should have some basic photography instruction in it.
Your camera focuses on a plane that is parallel to the sensor in your camera. The depth of field (DOF) is how deep or thick that plane is. Everything in that plane will be in focus though depending on the sharpness of your lens at both the center and periphery, the center portion may seem more in focus than the periphery. You use the autofocus or manual focus to fix the plane on which you will be focusing. Unless the flower is in a plane with nothing else in it, there is no way (without post processing) to have just the flower in focus. For example, a shot of a blossom shot from below or level with the blossom in the air with just sky or background also showing. Since your flower is inside something that shows in the shot, portions of that something else will be in the focal plane.
Moreover, you will need to stop down (use a higher numbered aperture) if you want to increase the depth of field and get more than a portion of the flower itself in focus. Shooting at 2.8 gives you a fairly thin DOF, which you can see from the areas you have circled.
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Raymond R
Your camera focuses on a plane that is parallel to the sensor in your camera. The depth of field (DOF) is how deep or thick that plane is. Everything in that plane will be in focus though depending on the sharpness of your lens at both the center and periphery, the center portion may seem more in focus than the periphery. You use the autofocus or manual focus to fix the plane on which you will be focusing. Unless the flower is in a plane with nothing else in it, there is no way (without post processing) to have just the flower in focus. For example, a shot of a blossom shot from below or level with the blossom in the air with just sky or background also showing. Since your flower is inside something that shows in the shot, portions of that something else will be in the focal plane.
Moreover, you will need to stop down (use a higher numbered aperture) if you want to increase the depth of field and get more than a portion of the flower itself in focus. Shooting at 2.8 gives you a fairly thin DOF, which you can see from the areas you have circled.
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Raymond R
Everything at a certain distance will be truly in focus. The greater your f number (i.e. the smaller the aperture), the more will appear "acceptably sharp."
Reducing depth of field
Telephoto focal lengths
Focus closer
Wide aperture
You could also go to extension tubes...you lose infinity focus when you do that.
Picasa has a very simple soft focus effect. You can control the amount of blur and the size of the (circular) out of focus area. The original for this was totally in focus.
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Gear listed in profile under "plan."
Someone stop me before I buy again, please!
Dave
Reducing depth of field
Telephoto focal lengths
Focus closer
Wide aperture
You could also go to extension tubes...you lose infinity focus when you do that.
Picasa has a very simple soft focus effect. You can control the amount of blur and the size of the (circular) out of focus area. The original for this was totally in focus.
--
Gear listed in profile under "plan."
Someone stop me before I buy again, please!
Dave
I'm currently reading Understanding Exposure (I have some other books I'm going to be reading as well) by Bryan Peterson but he doesn't mention anything about DOF being plane. I've skim through the D90 manuel I guess I'll read it more in depth. Thank you for your in-dept explanation.
RaymondR
Senior Member
Peterson is great! Love his books. But you need to start even more basic than that at first. Try all of the items on the Learn tab at the top of any page on this site. For example, here is the explanation of depth of field:
http://www.dpreview.com/learn/?/Glossary/Optical/Depth_of_Field_01.htm
Good luck and have fun. the D90 is a great camera.
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Raymond R
http://www.dpreview.com/learn/?/Glossary/Optical/Depth_of_Field_01.htm
Good luck and have fun. the D90 is a great camera.
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Raymond R
I've never used Picasa. Would you recommend Picasa over Aperture (not sure if you can do soft focus in this, still have a lot to learn in this program) or Photoshop? (I know my way around photoshop) They only problem I have in Photoshop is it a bit tedious to get the exact spots that are in focus and to get the blur to match.
Thanks. Yes, I'm really enjoying the book, I can tell its a lot of its is over my head but I've been writing down questions to ask (now I can just look it up first on the learn tab) I'll definitely look into the "Learn Tab".
Picasa is a free, simple, web-based editor for total beginners. Aperture is a DAM program, with some global editing capabilities...quite similar to Lightroom. Photoshop is the 800-pound gorilla in the room...it can do anything. To compare Picasa to these other programs is wrong headed.
Somehow, I doubt that you "know your way around Photoshop". You may need a simpler editor? Try Photoshop Elements 9?
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Charlie Davis
Nikon 5700, Sony R1, Nikon D50, Nikon D300
HomePage: http://www.1derful.info
"If ever a time should come, when vain and aspiring men shall possess the highest seats in Government, our country will stand in need of its experienced patriots to prevent its ruin."
-Samuel Adams, 1776
Well I've used Photoshop for a few years. so I have a good base understanding of how to use it. I've never heard or used Picasa. I didn't know it was free. Thanks tho.
Yeah, I can't decide whether I'm too cheap, too lazy, or both to get into photoshop. Picasa's great for a quick fix. As you can see from the photo I didn't do a super precise job of isolating on that light. I could probably save that, then go back and do a series of blurs, saving each time, till I got where I wanted. It's nowhere as precise as PS but for $0....
There are other nice features, too. One of the best, IMO, is that it's non destructive. Unsave, unsave, unsave...takes you back to your original, even if you cropped it. I've even done that like six months after the fact
@chuxter: Not sure what you mean by "web-based editor." True I can upload photos directly to a free web album (free up to 1 Gb, I think). My editing is off line...but you dload the program from Google.
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Gear listed in profile under "plan."
Someone stop me before I buy again, please!
Dave
Bad choice of words. What I was trying to say is that it's married to several web-based services. I'm a Google fan, but you can bet they have a profit motive in Picasa.
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Charlie Davis
Nikon 5700, Sony R1, Nikon D50, Nikon D300
HomePage: http://www.1derful.info
"If ever a time should come, when vain and aspiring men shall possess the highest seats in Government, our country will stand in need of its experienced patriots to prevent its ruin."
-Samuel Adams, 1776
pocketfulladoubles
Senior Member
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You will always have a region of acceptable focus. Wider apertures just make it more shallow. To get what you're after, you'll need to manually blur out the regions in post processing. One alternative (albeit an expensive one) would be to use a tilt-shift lens, and you can change which regions are in focus, but there will always be some part in focus.
baloo_buc
Forum Pro
The focus plane is a focus plane (i.e. extremely thin). Everything else is out of focus. You have a tolerance to the loss of sharpness so the plane has some depth until you reach that tolerance.
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Victor
Bucuresti, Romania
http://s106.photobucket.com/albums/m268/victor_petcu/
http://picasaweb.google.com/teodor.nitica/
http://picasaweb.google.com/vpreallize/
http://www.flickr.com/photos/v_petcu/
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Victor
Bucuresti, Romania
http://s106.photobucket.com/albums/m268/victor_petcu/
http://picasaweb.google.com/teodor.nitica/
http://picasaweb.google.com/vpreallize/
http://www.flickr.com/photos/v_petcu/
Ah, ok. IIRC now there is some other service it will offer to direct you to for on-line editing as well but I just use Picasa.
Another great thing about Picasa is that I can batch edit a lot of things. I select the pics I want to resize, click "export" and it changes them all to 640p or whatever I choose. You can set it so others can download your entire album, e.g. for when you shoot for friends and they want copies.
OP if selective focus is your bag, you could also look into lensbaby stuff.
http://www.lensbaby.com/tilt-transformer.php
--
Gear listed in profile under "plan."
Someone stop me before I buy again, please!
Dave
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