Camera Labs

I have recently started using a monopod, and I am fairly new to manual controls, hence my question:-

Using a monopod or tripod should allow longer exposure times, which in turn should allow higher f settings. Am I right in thinking that the narrower apertures should help me to achieve sharper focus.

I know that a wider aperture gives a shallower depth of field, but I was thinking in more general terms. I have had quite a few shots spoiled by fuzziness, and to a lesser extent I have been disappointed occasionally by a lack of sharpness in some of my pictures. This has happened even with the monopod, so I can't just blame camera shake for everything.
My knowledge of photography is a bit patchy and possibly out of date, so feel free to resort to explaining total basics.

Stopping down can help apparent sharpness in two ways: lenses tend to be sharper stopped down, and you also increase the depth of field so more is in focus. However you can go too far. Stopping down beyond a point will result in soft images again, as light is diffracted by the hole. You can argue when this happens, but you might be able to detect it at f/8 if you look hard enough on some cameras, although in practice it doesn't become significant for some way beyond that.

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What equipment are you using Ron? (long lens for birds?)

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Nikon D700 & D7100 bodies + Nikkor 300mm F2.8 VR11, 1.7TC, 50mm F1.4G, 16-35mm f/4G VR, 105 F2.8 VR macro, 70-300mm lenses. A couple of filters, Giotto tripod & ballhead. Lowepro Slingshot 302 AW

http://www.flickr.com/photos/oldcarlos/

Each lens has its own sharpest aperture. A good place to start looking is two full stops from the maximum aperture, according to more than one source I read when learning about photography, but one thing to consider is that many consumer lenses, and even a few higher-end lenses, do not open very wide. An example of the latter is the Canon EF 400mm 5.6L, which does not need to be stopped down two full stops to be sharp.

Diffraction is what happens when the aperture starts to get small. Some lenses start to show diffraction as soon as f/8. Yet, the desired depth of field may indicate f/11 will give us the image we want. In this case, we accept the compromise.

There are many times sharpness is not the most important factor when composing an image. It depends upon what we want. I often like shallow depth of field when shooting images for my own enjoyment of the art of photography. When shooting images for evidentiary purposes, however, I tend to stop down, because art is not the goal. A judge and/or jury needs to see a technically correct image, with as much in focus as possible. I will, sometimes, shoot the same scene at varying depths of field, to present a series of images, with particular items in the image in sharp focus, and other items blurred, but at least one overall scene image needs to have a quite deep depth of field.

To be clear, I do not consider myself an expert!

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Canon 7D/5D/40D/1D2N; Nikon F6, FM3A, & Coolpix A; Canon 40mm Pancake, 135L, 50L, 35L, pre-II 50mm 1.8, 100mm 2.8L Macro, 10-22mm EF-S, 28-135 EF, 400mm 5.6L; Nikkor 50mm 1.2 AI-S, 50mm 1.4G, 50mm 1.8D, 16mm 2.8D Fisheye, 180mm 2.8D, 100-300mm 5.6 AI-S; Tokina 17mm & 100mm 2.8 Macro

There's an old photojournalist expression that goes "f/8 and be there". It essentially means to set your lens to f/8, and just shoot without worry. Most lenses have a "sweet spot", which is (as RexGig mentioned) about two or three stops from maximum aperture. On an f/2.8 prime, the sweet spot is around f/5.6. On an f/3.5-5.6 zoom, it's somewhere between f/8 and f/11. On an f/1.8 prime, it's something like f/4. However, f/8 is usually a good comprimise that (for most lenses) gives you a sharp image, allows you to get a good depth of field and still blur the background a bit, but doesn't start to dull the image from diffraction.

I believe (but take this with a grain of salt as I'm not 100% sure), that diffraction is caused by the aperture getting too small, say f/22, f/16, even f/11 on certain lenses, and causes the light to bend and get dispersed in unnatural ways across the camera's sensor. This essentially makes the image less sharp, and so unless it's totally necessary (for example, you may need a very large depth of field, or it's extremely bright and you need to keep the exposure low), you should avoid going too high.

These images (courtesy of Luminous Landscape) show the effects of diffraction at f/8, f/11, f/22, f/32, and even f/45.

f/8


f/11


f/22


f/32


f/45


of course, that doesn't mean that you should always shoot at f/5.6 or f/8, if you WANT that blurry background and shallow depth of field, go ahead and open the lens up to f/2 or whatever it's maximum aperture is, or vice versa for a shallow depth of field. If you're indoors, it's very important to open it up all the way, it's better to get slightly less sharp shots than blurry shots that have the potential to be sharp. Be creative, because that's what makes a photo, not how sharp it is.

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-Evan

Gear: 7 Nikon Nikkor AI-S and AF-S lenses, SB-700 flash, Nikon D7000, Nikon FM, variety of accessories

"There are no rules for good photographs, there are only good photographs."
- Ansel Adams

Ron, have a look at the link from Gordon, it may help.

http://www.dslrtips.com/workshops/How_t ... ield.shtml

Cheers

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Nikon D7000, D40X, Nikkor 18- 200 VR II, f3.5-5.6, 70-300 AF non VR, Kit Lenses.

Thanks, everyone for the above responses. I would have responded sooner, but one of my settings must have been off resulting in me not being notified of responses (I think I've sorted it).

I didn't know that too small an aperture gave the opposite effect, so thanks for that.

When I was younger (in the days of film), I didn't have any kind of fancy camera, but I had a friend who was into photography, and he told me that one of the main objectives in photography was to achieve sharp pictures, and one of the main requirements for achieving this was a small aperture. He told me that you wouldn't widen the aperture unless you specifically wanted a shallower depth of field, or unless you needed the extra exposure.

I've not recently seen anybody place the same emphasis on a small aperture in order to sharpen pictures, so I was wondering - is digital different from film in that sense? For example, is there a preference for avoiding high ISO settings because of the increased noise, and because of that, is there a preference for achieving the required exposure by using wider apertures? As I remember it, if you wanted more sensitivity with film, you payed the extra for "faster" film, which enabled faster exposure times while keeping the aperture small. (As I said, my knowledge is patchy and possibly out of date!).

With the latest generation of CMOS sensors apparently delivering on the promise of less noise in low light situations, is it time to revisit the idea of increasing sharpness by using smaller apertures?

(I realise there is more than one question here, so feel free to comment on any part that strikes a chord with you).

Nikon P7700. As I said, I'm new to manual controls, and I know that the P7700 is a fixed lens camera, but I'm hoping that it will be a good learning tool, since it seems to have manual options for just about everything. I may eventually move up to a DSLR or CSC.

Everything you said made sense to me (a rare and wonderful thing ).

And thanks EvanK for another step on the learning curve.

....and thanks 4xxx for the link. I'll check it out when I can give it the required concentration.

Your sharpness-obsessed friend would be the film equivalent of a digital pixel-peeper. Ugh.

Henri Cartier-Bresson has a famous quote: "Sharpness is a bourgeois concept".

I do like a sharp image, and I like my focus to be in the right place, but if a shot has something special about it despite not having the perfect focus or being tack-sharp, I'll still keep it.

This photo from my trip to Florida is my favourite of the whole trip... There's camera shake and missed focus (it was an arms' length selfie in low light with a crappy lens) but it evokes an emotional response and that makes the photo:



Another - this was intentional - but it's the bride's favourite from her wedding day, because as she told me later, it summarizes the whole experience into one frame: a whirlwhind. Sharp? Nope. In focus? Who can tell. Emotion? Yep.

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Sounds like a good perspective. You're right about not being too particular. I'll be happy if I can just learn enough to avoid any more major disappointments.

Having said that, it's still difficult to avoid the twinge of envy I feel when I see really sharp pics.

Nice, pics, BTW. You make a lovely couple. Has anyone ever told you that you look like Tom Paris?

Hi Ron. I was just wondering if you were using a DSLR with a long telephoto lens when you mentioned the monopod. Hence the reason for asking.

Do you notice images `less sharp`than you'd like, across the whole range? (wide-normal-zoom)
Are shutter speeds fast enough Vs any movement in your subjects?
Is there enough light to keep ISO low enough so as not to introduce too much noise (maybe iso 800 .... or ideally less?)

Auto focussing tends to be slower the more zoom you use.

Have you tried the different AF settings? If you want focus on a particular area, have you tried `spot/centre`, rather than Auto? (or vice versa)


Also, is the image stabilization on, while hand holding?

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Nikon D700 & D7100 bodies + Nikkor 300mm F2.8 VR11, 1.7TC, 50mm F1.4G, 16-35mm f/4G VR, 105 F2.8 VR macro, 70-300mm lenses. A couple of filters, Giotto tripod & ballhead. Lowepro Slingshot 302 AW

http://www.flickr.com/photos/oldcarlos/

pretty much sharp all the way when I tried the Leica 50mm Summicron regardless of aperture ^^

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http://www.AnderssonPhoto.com
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