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Getting Sharp Images

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aniltulsi:
I see many excellent sharp images in the forum, and I would love to know the best way to get super sharp images, especially with long focal-length lenses and for macros.

Few things that I understand, but are not sufficient for sharp images, are listed below:

Lens:
To begin with, the lens needs to be sharp enough to get the sharp images. This is the baseline, without which, we can not move forward. And sharp lenses are expensive. But is it so? Most kit lenses produce excellent sharp images at some apertures. Most lenses have some sweet spots. So in that sense, most of our cheap lenses should also be able to produce sharp images. I have seen great images from 500mm primes, as well as the Sigma 50/150-500 lens zoom lens. How do you get such sharp images? So most lenses should be able to produce sharp images at some apertures, and some good lens produces sharp images at many apertures. Is this statement correct? The Chromatic aberrations in also an issue in some lenses, that seem to reduce the sharpness. But modern camera’s fix them in the camera itself, and some can be fixed in the post-production.

Focusing:
Of course, one needs to focus the properly to get sharp images. Now what are the best ways to focus accurately? In the olden days, with split image in view finder, the manual focus used to be quick. But now without it, focusing is more automated, making it even more quicker. However, using the right focusing mode helps in different situations. But before discussing them, just want to highlight one point on Multi-Point focus. Some people think that Multi-point focus helps focus at multiple people or objects, so that all of them are in focus. However, it may be noted that a lens can only focus on single point, and this option of Multi-point is a camera function, to automatically decide on which point to focus on. I don’t use this option, as I think I know better than the camera which object I want to focus on. Various focusing options available are:

Single point focus: This focuses on the focus point selected. Normally, people keep this at the center point. If the subject is at the corner, we need to first compose the camera with center point at the subject, focus it by pressing half way the shutter release button, recompose the subject to the corner, and click fully. 

The Pro and Cons of this method are:
                Pros: Simple and quick
   Cons: Shifting camera may affect focus accuracy

Another option in the single point focus is to Select focus point available in the camera. Some have 3 points, some have 9, some 11, 36, 51 etc. Pro/Cons for this method are:
                Pros: More accurate focusing, as camera is not moved to recompose
   Cons: More time to select the focus-point, The selected focus point may not be a cross-type, impacting focus accuracy. Also, your subject may not be at the fixed focus point.

More interesting focusing option is the Continuous focusing with 3D tracking. Once you focus the subject at the selected focus point by pressing half button, the camera keeps on tracking the subject even if the subject moves front or back or across the frame. Pro/Cons are:
   Pros: Movement of camera or subject does not result in loss of focus. Excellent for flying birds or running animals. Good for playing kids too.
   Cons: Camera gets confused if there are multiple subjects or have other obstructions between camera and subject. Once I was focusing a bird on a tree, and with so many branches in between, the focusing kept on jumping here and there. 

What focusing options do you use to get best results?

One problem with auto-focusing is that some lens-camera combinations don’t focus at the correct position, but either front-focus or back-focus. The solution is to either get it fixed at the service center, or use Micro-focusing adjustment, if available in your camera.

Do you use Micro-focus adjustment? Do this option has any side-effects?

Aperture:
One option to avoid missed focus is to use smaller aperture, so that you get larger depth-of-field, and any minor miss-focus is taken care of. Moreover, most lenses are sharpest in mid range than at full-open or smaller apertures.

Do you use smaller f-stops like f5.6 or f8, even if your lens support f1.4 or 2.8?

Camera Shake:
One major issue for getting sharp image, especially with long-focal length lenses is the camera shake. To avoid the camera shake, we need to keep the shutter speed high. The thumb rule is to keep the shutter speed more than the reciprocal of the focal length (Fx) being used. So if you are using 200mm lens, the shutter speed should be at leat 1/200sec. However for Dx format, as the focal length is 1.5 times, the shutter speed for the same lens should be at least 1/300sec. Various other options are:
 
Tripod:
The best way to get sharp images at slow shutter speed is to use the tripod. However, they are bulky and good ones are expensive. As your lens size increases, your tripod size also goes up, along with the price-tag. But there is no way out, and tripod is a must for long-focal length lenses. 

Remote:
One problem is that even touching the camera to click a picture can introduce shake for Macro or Long-FL shots. Use of wired or Radio remotes help in clicking pictures without touching the camera. I personally find the Radio remote quite effective.

Delay mode
Sometimes, even using the remote does not help, as movement of the mirror in the camera introduce shake. One option is to use delay mode, where the picture is taken after a second of the mirror going up. Best used along with remote. However, this may still not be enough. Not all cameras have this option.

Mirror lock-up
Another option is to have the Mirror locked up when you click for the first time, and picture is taken when you click the second time, waiting good enough time for the vibrations from the mirror to die down. This gives better results than the delay mode. Best used along with remote. Not all cameras have this option.

What options do you use?

What are other things that you do to get sharp images, that are not listed here? Looking forward to expert guidance.

iamsomnath:
excellent write up anil. I just share one more aspect which is useful while shooting macro etc.  While doing macro we usually use manual focusing and generally use tripods, don't we? so i have used this workflow for better result ( works with lenses having aperture collar):-

1. adjust the tripod properly ( keep the image stabilization off)
2. stop down the lense to the largest aperture
3.Put the camera on live view & maginfy if allowed in your model.( you will have to shift focus point to the
   desired object)
4.Rotate the focussing collar until the right focus comes into live view
5.stop up the lense to F8 or whatever stop you seem appropriate
6.click the shutter ( with remote or delayed timer)

this method has given me sharp results with lesser time ...

regards

toofan:
Shutter Speed.

Hankosaurus:
Great discussion going here.

Don't forget panning:

Sometimes the camera needs to track a moving subject to minimize the subject motion blur that could otherwise be emphasized.

And contrast:

Contrasty images can seem to be somewhat sharper too. A sharp, lower contrast lens may seem to produce less sharp images than an otherwise comparable, but contrasty lens. I see this when comparing images between a 50mm f2 1954 Leitz Summicron and a 50mm f2 1969 Jupiter 8M. The Jupiter, a Zeiss Sonnar copy, has more modern coatings. Its images look sharper than the Summicron's, but on close inspection it is not quite so. And that Summicron's look is preferable with some people images than is the harder look of the "Zeissy" Jupiter 8M.

And software:

Nowadays, and up to some point, the soft edges within an image can be made to "appear" sharper than they really are.

And concept:

What's the point in having a sharp image of a fuzzy concept? That may be the most important part of all.

:)

arunchandrachennai000:
Plenty of light, exact focus of the subject and right aperture. In some situations we have to use artificial light source and if needed tripod can be used.

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