Keeping an distant view sharp as well as a closer image.

[kexkez]

ameerat42 suggested I post here to get an answer to my question.


Is it possible to get a clear view through the doorway without losing sharpness on the actual door?


Camera 550D canon 18-55IS lens

[Kym]

Possible by using the Hyperfocal distance if you can get back far enough, eg. f/16 10meters and focus is from 5m to infinity

http://www.dofmaster.com/dofjs.html

[arthurking83]

Yes!

it's called DOF(depth of field) and you want to make it deep.

creating the illusion of a deep DOF is made with a small aperture, which is a numerically large value.
The opposite is when you want to create a shallow DOF, where you use a large aperture, which is the smaller numbers of the aperture value range of your lens.

In your case, some times it's not so simple to create a deeper DOF, as there are many variables involved.

The sure fire way to get a deeper DOF is with the use of a smaller focal length. That is 18mm instead of 55mm. Other variables to consider are distance from the subject and exactly where you set the plane of focus.

a few quick comments:
There is no exif data to allow anyone to help you determine a better set of camera settings to use for next time.
If you want to 'salvage' this image, I think you may be pushing stuff uphill from here. Someone with expert PP skills may be able to process this image into a sharper rendition, but I suspect only for small output/resolution.

My initial thoughts were that you have used a wide open aperture setting. Image sharpness looks to be variable across the frame, and particularly lacking at the edges.

eg. if you used f/4 on a f/3.5 lens, then really you should have set aperture to f/11. Also.. to ensure maximum apparent DOF for the scene as you would have wanted it to be, you would have focused somewhere not to far behind the main stone wall, using a hyperfocal method(but not strictly having to adhere to the theory of it all).

[kexkez]

Thank you both for the information and advice. Time to do some reading.

[ameerat42]

Hi again, Kexkez. Read for sure, and here are some illustrations that (I hope) might help.

Using "Hyperfocal distance method", you are basically asking, "What will be in appreciable focus if I set my lens aperture to (say) f/16? Or f/8, or f/4?" You are then setting your aperture to give you a good Depth-of-Field" (DOF) based on that setting.

Older camera lenses were helpful in helping you get a visual cue of this "acceptable" range of focus (DOF) because many had distance scale, aperture scale, and lots of other little scales displayed on the lens barrel.

Below are three pictures of an old Minolta lens that shows you just this, including a "depth-of-field" scale, which is readily useful for seeing the "Hyperfocal distance".

Each picture illustrates the "Hyperfocal distance" for each of f/16, f/8 and f/4 apertures, respectively, for this lens. Look at the first image. Basically, you would...

1) Set the desired aperture, eg, f/16, then
2) Set the distance scale (focusing ring) so that the "infinity" mark is opposite the "16" reading of the DOF scale.
3) Your "Hyperfocal distance" range will be everything between the two "16" marks, in this case from about 2.7m to "infinity".
1. HD for f/16


If you look at the following two images you will see that the "Hyperfocal distance" decreases as you open up the aperture - use a lower f/stop number. You can see that for f/8 it is about 3.5m to "infinity", and for f/4 it is about 10m to "infinity". (For f/4, the "R" mark for infra-red focusing is where you set the "infinity" focus ring mark.)

2. HD for f/8


3. HD for f/4


What's the use of "Hyperfocal distance"?
One use is what you want it for, and another is for (so-called) Street Photography using semi-automatic cameras cameras, where you want to grab quick shots without having to focus each time.
You would set you camera to Av mode, set your aperture and distance, and let the shutter speed take care of the exposure. And cheaper, fixed focus cameras of yore relied on this principle to yield fairly sharp images over a large range.

Just one last thing. The Hyperfocal distance does not have to include distant objects. You can set your farthest distance at say 10 metres, and then your HD range at f/16 would be about 2-10 metres. That idea might be useful in more confined spaces.
Am.

[arthurking83]

Thanks to Am for that reply. Makes it easy to 'visualise' what hyperfocal is and does for 'ya.

Only problem is to apply that to the real world, and in the real world 99% of DSLR owners use zoom lenses, and zoom lenses don't have the marking required to set hyperfocal easily.. so when you use a zoom lens, you kind'a need'ta do a bit of guesswork.
Experience helps with that, where instead of setting the focus distance at the f stop markings, you literally set the actual focus distance by estimating where you think those marking would line up.

take for example(and I'm using a 50mm lens). In Am's first illustration, you can see that the lens is focused for hyperfocal from between about 2.7m to about infinity.
(note this is not exact numbers... the focused areas in the DOF zone, are not an implicitly focused part of the image.. they look acceptably focused to the average eye, and a well trained eye will see that there is not focus all the way from the front to the rear distances in the DOF zone)
So, back to the settings, as in the first example, if you want as much in focus, you will see that the lens is actually focused at the 5meter range.
Use that figure for when you only have access to a zoom lens, so that if you are shooting at 50mm or so with your 18-55mm kit lens, set the lens to f/16 and focus at 5m and you should basically be covered(as long as the camera doesn't re focus for you as you make the exposure!)