1) I have 50mm f1/8 prime lens and 75-300mm lens. Please suggest me what setting I should use to keep everything in focus, because background comes blur and i do not want to keep background blur .
2) When I shoot group photo, than some people face looks blur. I tried to increase aperture.
Please suggest me what shutter speed and aperture to use for both cases.
Thank you.
When you focus on a subject at a specific distance from the camera, that object will be in-focus. As you know, objects that are close by, both in front and behind this principle subject will likely be in-focus also. We are talking about a span of distance fore and aft of the focus point that will image acceptably sharp. This span is called depth-of-field.
We can both expand and contract the depth of field span by changing the lens aperture setting. Tiny aperture numbers like f/22 or f/16 or f/11 expand the depth of field zone. f/22 has the greatest span of depth of field followed by f/16, etc. So the simple answer is to use f/22 or f/16 when taking the picture.
The first step you must take is to read your camera manual. If you do, you will learn about depth-of-field and what settings your camera offers that will maximize depth of field. I will bet your camera has a landscape or scenery mode that will automatically make the needed adjustments for you.
Did you know that you can set your aperture and the distance you are focused upon in a special way that maximizes depth of field? That setting is called the “hyperfocal distance” setting. Such a setting keeps far distant objects - objects at infinity (∞) - in focus and maximizes how close objects will image in-focus.
Hyperfocal settings for 50mm lens with regards to aperture is as below -
Note: infinity symbol (∞) means as far as the eye can see (from old French).
Try using 50mm lens in aperture priority and use the smallest aperture you can (e.g. f/16)
The zoom lens can compress the image background when in use, so it will not all be in focus, even on occasions where you use an aperture smaller then f8.
Your best bet is to use your 50mm with an aperture between f8-f16. Since that lens does not zoom and has a fixed focal length, it will not compress your background. Starting around f8 and beyond, the lens will allow everything in your frame to be in focus. Wider apertures from f8-f1.8 will reduce the amount of your frame that will be in focus.
Your shutter speed will depend on the amount of light available to properly expose your image when using a given aperture value. Try using your camera in Aperture Priority (A) mode so that you set the aperture and the camera will figure out the shutter speed for you. Once you get the hang of that you can switch to manual and practice exposing with your in-camera exposure meter.
