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View Full Version : Calling all experts.... or not....


Jrabbit910
09-26-2007, 07:35 AM
I have been noticing pictures where the background is blurred and the focal point is crisp and clean.... can someone tell me how this works.... How do you get the picture like this????

Thanks so much for your help...

Amy
09-26-2007, 07:42 AM
Hi JRabbit! I'm no expert, but this one I can answer.

It's called depth of field - how much of the photo from front to back is in focus. You achieve this by using as wide of an aperture as your camera is capable of. Using the macro setting on most point & shoots will usually give you the widest aperture.

Nikel
09-26-2007, 09:03 AM
Yup, you want to use a large aperture (which could get confusing because large apertures are small numbers, 1.8 is a large aperture while 22 is a small aperture). Also, the focal length of a lens makes a difference too, as does the distance we between the lens and the subject.

H.E. Pennypacker
09-26-2007, 09:14 AM
I'm not an expert either, but I'll try to add to this. The effect you're talking about is called "bokeh". There's a lot of info out there about what's good bokeh and what's bad bokeh. It all has to do with the lens, the focal length and aperture and their effect on the blurring. Essentially it's using a low f/stop (wide aperture) to give you a shallow depth of field so the subject in the foreground is in focus and the background is thrown out of focus. In general, I think it's pretty tough to get good bokeh on a point and shoot, especially if the P&S doesn't allow you to manually set aperture. With DSLR, different lenses have better bokeh than others. I'm just about set to order a Nikkor 50mm f/1.8 because it should have much better bokeh because of the wider f/1.8 aperture than the 18-70mm f/3.5-4.5 I have now. And please, all you experts out there, clarify or correct me if I'm wrong. I'm still learning, too!

Jrabbit910
09-26-2007, 09:28 AM
Thank you so much... I really do appreciate the advise so far.... The camera that I have is a Kodak DX7590.. I have had it for a few years & I like it but every time I try and manually set something it wont let me do it... I dont know if I am doing something wrong or if it just keeps telling me that I am an idiot & I shouldnt do what I am trying to do!! :rotfl:

I really want to get more into taking pictures especially now that I have the perfect subject (my ds). I dont know if I should buy a new camera or keep this one and just keep practicing... :confused3

handicap18
09-26-2007, 09:52 AM
Try putting on the aperture priority setting (Av or A). Then choose the smallest number, probably f/2.8. Next best bet is to find a subject that has a lot of space between it and what ever is behind it. Maybe a flower at the edge of a garden and the trees or house or what ever is way far back in the background. Use the longest part of the zoom and get as close as you can so that the camera will still be able to focus properly. See how that works out.

Its tough getting good shallow depth of field with a PnS camera. They use much smaller lenes than SLR camera's do so its harder to get a good wide aperture. Even though you may use f/2.8 on a PnS, its doesn't give the same effect as f/2.8 on an SLR lens.


On the flip side, getting a very deep depth of field (DOF) is much easier with a PnS. Say you come across a field of daisy's and you want all the daisy's to be in focus. Because of the small lens you can get a very sharp DOF with everything in focus pretty easily. With SLR camera's, your focus has to be at a certain spot within the field and you have to use a small f/stop. There is actually a mathamitacal equasion (sp?) to get your focus in the correct spot. Though I've never used it. I usually just hope for the best.

H.E. Pennypacker
09-26-2007, 09:58 AM
Thank you so much... I really do appreciate the advise so far.... The camera that I have is a Kodak DX7590.. I have had it for a few years & I like it but every time I try and manually set something it wont let me do it... I dont know if I am doing something wrong or if it just keeps telling me that I am an idiot & I shouldnt do what I am trying to do!! :rotfl:

I really want to get more into taking pictures especially now that I have the perfect subject (my ds). I dont know if I should buy a new camera or keep this one and just keep practicing... :confused3

On this camera, to get the effect you asked about, set the mode dial to "A" which will put the camera in aperture priority mode. Then you can set the aperture (the f/stop) manually using the jog dial on the front of your camera below the shutter release. The camera will continue to control the shutter speed and ISO, but let you play with the f/stop. Set it to its lowest setting, f/2.8. Note that as you increase the optical zoom, the lowest available f/stop will probably increase, so you'll probably want to zoom all the way out to the widest setting (38mm) and physically move closer to your subject so you can keep the f/stop at the lowest setting.

Jrabbit910
09-26-2007, 10:07 AM
Thank you a million times over....

I am going to shoot some pre-halloween pics this weekend and I will post them afterwards...

Again thank you all. I really do appreciate it... :goodvibes :grouphug:

boBQuincy
09-26-2007, 11:18 AM
I'm not an expert either, but I'll try to add to this. The effect you're talking about is called "bokeh". There's a lot of info out there about what's good bokeh and what's bad bokeh. It all has to do with the lens, the focal length and aperture and their effect on the blurring. Essentially it's using a low f/stop (wide aperture) to give you a shallow depth of field so the subject in the foreground is in focus and the background is thrown out of focus. In general, I think it's pretty tough to get good bokeh on a point and shoot, especially if the P&S doesn't allow you to manually set aperture. With DSLR, different lenses have better bokeh than others. I'm just about set to order a Nikkor 50mm f/1.8 because it should have much better bokeh because of the wider f/1.8 aperture than the 18-70mm f/3.5-4.5 I have now. And please, all you experts out there, clarify or correct me if I'm wrong. I'm still learning, too!

You have it mostly correct. :) The bokeh itself actually refers to the quality of the out of focus areas, some lenses do better than others in this respect, even at the same aperture. Lenses with many blades in the aperture often have smoother bokeh due to the more circular aperture. Canon's 50mm f/1.8 and 50mm f/1.4 are examples of this, where even at f/1.8 the f/1.4 lens has a smoother bokeh. At 3-4x the price it *should* do something better! ;)

It is difficult to get a P&S to selectively blur areas of the image partly due to their smaller apertures, partly due to their greater depth of field. It can be faked to some degree of success by adding a layer to the image, blurring it, and masking out the area that should be in sharp focus.