Aperture - How do you choose the best?

Hi Guys!!

When talking about plane spotting, we usually need higher shutter speeds to get a sharp photo with no motion blur. Regarding this particular condition I was wondering why people choose to photograph planes with f8 for example instead the maximum lens aperture, usually 5.6 if you don't have a better lens (i.e. f2.8 or f4.0)??

I usually take pictures with a Nikon 70-300mm or SIGMA 150-500mm and always use the maximum aperture to get the fastest speeds. What situations should I use smallest apertures??

Regarding zoom lens like 70-300, the depth of view is not so affected by smallest apertures, is it?

or...

When we are spotting, a nice bokeh usually is not achievable in most of pictures.

What do you think? How do you chose apertures when taking plane shots or using a telephoto lens around.

Thank you in advance!!

Best Regards,

ABRITTA.

This post has been edited by Ricardo Abritta on 4th April 2014 - 05:59

There is a general rule of thumb, a rough guide if you want to call it that, which says use a shutter speed greater than your lens focal length.

For example, if you are going to be photographing an aircraft zoomed out at 300mm, then you want to be using 1/300th, 1/500th or more, so that has a direct impact on your aperture.

Unless there is a valid reason then personally I would not use anything other than f/8, as that gives me an acceptable depth of field and it gives good results on all my lenses. So it becomes a bit of juggling act.

With experience you will learn what you can and what you can not get away with.

The best way is to experiment for yourself and see what you can get away with but above all be self critical with the results.

Hi!

Also you should shot 2 or 3 steps above the maximum to minimize vigneting, depending of your lens, the better results are normaly between 8-11, if it´s an 2.8 may be more ... for example my Zuiko Lens works very fine between 5.6 - 16 ( check my pics http://www.airplane-pictures.net/member-profile.php?p=3178 ;-) )

If you shot with a 400mm and a crop camera ( x1.5 factor ) you should think about 600 mm, so shot at least at 640 ... use iso with moderation ;-), If you shot less, try burst mode and spect a panning pic ;-)

The depth of field is critically when you are close to the subject ... in usually cases that the plane is at your infinite focused, may be very low differences, not apreciable.

Regards!

MaQui.-)

This post has been edited by maqui on 4th April 2014 - 23:27

Hi Guys!!

Thank you for your tips. I did some tests here and got better results with f8 than f5.6. I just need to take care about some dust spots on my sensor as they become more visible at smaller apertures.

With f8 I noticed better colors, and the image a little bit more sharp.

Thanks again for your time!!

I seem to have found a nice balance at 7.1 with my Canon 100-400L. So far Ive not had any rejections for lack of sharpness at this aperture. Ive attached a recent example which Im happy with and it was accepted on here

Garfield

Attached photos:

Don't forget that if you can not actually obtain a well exposed photo, shooting in M mode of course, then you need to alter the ISO setting which has a lot to do with gaining your image. I wouldn't stick to f/8 either, it's true for most lenses it is optimally sharp but don't be afraid to open up or stop down a stop or two.

Generally I would try to stick to the lowest ISO and speed for a given situation when trying to play with the aperture for any given camera-lens combination.

So if it's an object moving slowly or parked - on a well lit day, well within the mid-range of the lens focal point, one could enhance the sharpness by bumping up the f-stop (closing the aperture) - assuming bokeh is not also desired as part of the photo composition. On the other hand, if the same object was moving fast, in a low lit condition and at the far edge of the limit of lens, aperture has to be as close to open as the lens will allow (say 5.6 on a 600mm lens) in order to both freeze the object AND minimize the effect of too high a ISO.

Here are some examples:

1. high f-stop (f20, ISO 320, 460mm, 1/250th, Nikon D7000, Tamron 150-600mm) for an object that is far away, and lighting is low (so it's not as simple as multiplying focal distance by two to get the shutter speed - such a simplification has no basis in optics!): http://www.airplane-pictures.net/photo/469614//

2. low-ish f-stop (f7.1, ISO 125, 18mm, 1/200th, Nikon D7000, Nikkor 18-55mm) for an object that is very close, lighting is lowish): http://www.airplane-pictures.net/photo/425199/c-ghta-air-canada-jazz-de-havilland-canada-dhc-8-300q-dash-8/

3. low f-stop (f4.5, ISO 100, 70mm, 1/100th, Nikon D40x, Nikkor 55-200mm) for a medium range object, moving fast at low light - and slowed down the speed to get motion blur - hence compensated by opening up the aperture: http://www.airplane-pictures.net/photo/278574/s2-afl-biman-bangladesh-boeing-737-800/

4. medium f-stop (f10, ISO 200, 100mm, 1/400th, Nikon D7000, Nikkor 70-300mm) for a medium range object, moving fast during daylight: http://www.airplane-pictures.net/photo/414869/s2-afm-biman-bangladesh-boeing-737-800/

Bigger the sensor size in the camera, higher the ISO without degrading image quality; likewise, faster a lens, higher the shutter speed it can support without losing detail.

Bottom line: all else being equal, more money you spend, sharper your picture :)

This post has been edited by Shabbir A Bashar on 16th October 2014 - 08:42