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12-30-2011, 07:35 AM   #1
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My attempts at Depth Of Field

Well today i wanted to get a grip with DOF, before reading Understanding exposure and learning a bit id never heard of it so it is new to me, dnt think I've done bad thigh,, i do wish i could of got a smaller DOF and made the background blurred a bit more, but i was using the largest aperture i could and prated around with all the other settings and that was about the best shot would be interesting to see others DOF pictures to see how they did them and any advice is always welcome

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12-30-2011, 08:04 AM   #2
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Was this with the 18-55 kit lens? You're not going to get a tremendous amount of bokeh (the out of focus area) with the widest aperture on that lens. The smaller the F stop number, the wider the aperture, the narrower the depth of field. If it's the kit lens, it has a widest aperture fstop of 3.5 at 18mm, and 5.6 along the longer end. A lot of the sweet bokeh shots you see are shot between 1.4 and 2.8.

Looking at your shots, i'm guessing it was maybe even a longer lens than the 18-55 kit. It might also help to know if you were at the long or short end of the lens's focus. I don't know for sure, as I haven't read any books on the subject matter, but my experience has shown me that the further on the focus scale you're looking, (closer to infinity focus), the less bokeh you'll have in scenery behind your focused subject. However, on the longer end of the focus, things in front of your subject will have good amounts of bokeh.

This next picture by no means is great, but it was a 28mm f2.8 lens at 2.8. It's not a building in the background, so it may not be totally useful for comparison, but I think it helps.
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12-30-2011, 08:17 AM   #3
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QuoteOriginally posted by Murgy91 Quote
i do wish i could of got a smaller DOF and made the background blurred a bit more, but i was using the largest aperture i could
Comes down to aperture and distance to subject. The more of the first, and the less of the second, the thinner the DOF. So you can get nice blurred backgrounds even with a relatively slow lens, if you get close to the subject. As you've done here.

Here's an example with the 18-55 kit lens, run out to 55mm, at f/8. Probably at the minimum focus distance, so even at f/8 the DOF is quite shallow.

12-30-2011, 08:20 AM   #4
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baro-nite is correct - the aperture is most important, but don't neglect subject distance to background. When your aperture is limited, moving around to get the best background (a background that is far away or a background that is lacking clutter) will be best for out of focus regions.

12-30-2011, 08:21 AM   #5
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sorry i forgot to say which lens its the 50 - 200mm, however the min is f4 at 50m & f5.6 at 200m, that shot was at 200m with aperture of 5.6 (lowest it could be) , maybe this is reason to invest in a new lens :P iim still learning atm and have no idea what to purchase, atm i have the 50 - 200 and the 18 -55 , the main use of the camera once i get the hang of it will be to take portrait pictures and scenery while I'm working away
12-30-2011, 08:26 AM   #6
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You really ought to check out the bokeh thread... there's hundreds of photos there for inspiration, and most with Exif info attached.

Bokeh is a Japanese word meaning Blur. On the other end of the spectrum, you might look at landscapes, or macro photographs for deep depths of field.

Edit: DA 50-200mm is a fine lense with great bokeh IMO. No need to replace that one (I think you will find it is quite expensive to go up to a 200 F4 or F2.8)
12-30-2011, 08:36 AM   #7
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QuoteOriginally posted by baro-nite Quote
Comes down to aperture and distance to subject. The more of the first, and the less of the second, the thinner the DOF. So you can get nice blurred backgrounds even with a relatively slow lens, if you get close to the subject. As you've done here.
Ahh wow, when i was reading i read it as the more aperture and bigger distance the better, which is why i was using the tele lens, the tree is a good 15-20 m away..

just put the k18 - 55m lens on and decided to try items on my desk, the camera wldnt focus on the trackpad so did a mouse instead i love it


Name:  Bokah Mouse.jpg
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QuoteOriginally posted by mattt Quote
You really ought to check out the bokeh thread... there's hundreds of photos there for inspiration, and most with Exif info attached.

Bokeh is a Japanese word meaning Blur.

Edit: DA 50-200mm is a fine lense with great bokeh IMO. No need to replace that one (I think you will find it is quite expensive to go up to a 200 F4 or F2.8)
Ahh right, i was searching the forums for depth of field but now i think i may have only searched the k-r topic, ill bear that word in mind

god to hear about the lens, ill have to get closer to that tree next time!
12-30-2011, 08:43 AM   #8
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QuoteOriginally posted by Murgy91 Quote
sorry i forgot to say which lens its the 50 - 200mm, however the min is f4 at 50m & f5.6 at 200m, that shot was at 200m with aperture of 5.6 (lowest it could be) , maybe this is reason to invest in a new lens :P iim still learning atm and have no idea what to purchase, atm i have the 50 - 200 and the 18 -55 , the main use of the camera once i get the hang of it will be to take portrait pictures and scenery while I'm working away
It's a fine pair of lenses, and using them will give you a better idea of your favorite focal lengths.

Neither is ideal for portraiture, however. For general portraiture you don't want to be especially close; once you're closer than a few feet from the subject you get noticeable perspective distortion (large nose, small ears, etc.). And if you aren't close you won't get a thin DOF with a slow lens. And for portraiture you very often do want thin DOF.

I'd say a worthwhile investment would be a fast prime (f/2 or faster) somewhere between 50mm and 100mm. 50mm is great for general portraiture. 100mm is for tight head shots. Search the forums on "portrait lens" or something similar and you'll find loads of threads.

12-30-2011, 08:46 AM   #9
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QuoteOriginally posted by baro-nite Quote
50mm is great for general portraiture.
Also probably the cheapest to come by.
12-30-2011, 08:49 AM   #10
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Thanks will try that search and see what i can find


QuoteOriginally posted by mattt Quote
Also probably the cheapest to come by.
definatly not point spending my pennies until i can use the thing :P
12-30-2011, 09:50 AM   #11
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I experimented a lot back in the summer with bokeh and its relationship to aperture size and distance to subject. It's especially about the latter. Even with a slow zoom lens, subject isolation is possible, heck even stopped down much farther than its max aperture. Of course, not all subjects will lend themselves to this, but here are a couple examples.

300 mm f/11 1/100 sec 200 ISO


300 mm f/14 1/80 sec 200 ISO


Behind the twig this dragonfly was perched on is a small field area that had a bunch of yellow flowers, goldenrod I think. The distance from subject to background was many times the distance of camera to subject, but the latter was quite small. I crept up close to this one. The bug is a Yellow Legged Meadowhawk, one of my favourites for its bright red colours. It's devouring a house fly that I watched it catch, in the second shot. I think it took off and returned to that twig 20 times as I was shooting. I love dragonflies, such forgiving subjects.
12-30-2011, 10:15 AM   #12
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QuoteOriginally posted by Philoslothical Quote
Behind the twig this dragonfly was perched on is a small field area that had a bunch of yellow flowers, goldenrod I think. The distance from subject to background was many times the distance of camera to subject, but the latter was quite small. I crept up close to this one. The bug is a Yellow Legged Meadowhawk, one of my favourites for its bright red colours. It's devouring a house fly that I watched it catch, in the second shot. I think it took off and returned to that twig 20 times as I was shooting. I love dragonflies, such forgiving subjects.

beautiful pictures... sadly there is not a lot of wildlife where i live, Im reading up on bokah portraiture atm online in-between carrying on with understanding exposure book. I do live in the middle of fields are forests though so i may have to put my boots on and try take some more bokah pictures, this time remembering that distance from subject to background needs to be large and distance from me to subject needs to close..ish..

That right? way i read it,..
12-30-2011, 10:28 AM   #13
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Yep, that's right. These shots I wouldn't call macro, but they're definitely closeups, like maybe a 1:5 or 1:6 ratio. They're slightly cropped. I *think* I had unlocked the "macro" setting on the lens, but was nowhere near the 1:2 maximum it can do. If anything, the closer you get to subject, the harder it is to get the whole subject in focus, hence the need for a smaller aperture.

Here's one I took recently, with the same principle of close subject, distant background. I used the same 70-300 lens, stopped down to f./8. It's kind of a nothing shot, but I liked it for some reason. Maybe due to the way everything was dying back here with winter incoming, it caught the mood of it a bit.

120 mm f/8 1/60 sec 200 ISO
12-30-2011, 10:32 AM   #14
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QuoteOriginally posted by Philoslothical Quote
If anything, the closer you get to subject, the harder it is to get the whole subject in focus, hence the need for a smaller aperture.
yeh that did confuse me a bit with portrait on how i would get everything on the person in focus, its starting to make more and more sense now though sadly work calls for now and ill have to put the camera down might take it to the concert and see if i can get some good pics, god knows what lighting will be like thigh!
12-30-2011, 10:36 AM - 1 Like   #15
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QuoteOriginally posted by Murgy91 Quote
yeh that did confuse me a bit with portrait on how i would get everything on the person in focus
That's just it, with portraits you don't need or even want the subject entirely in focus. Some of the most compelling portraits have sharp focus on the eyes but little else.
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