dione961

I recently bought a used Tokina 11-16mm f/2.8 wide angle lens. It's my 1st lens with distance scale but being a novice I don't know how to use the scale at all let alone properly (the lens came without a manual). I read some info on DPS about the scale & on hyper-focal distance but it is descriptive (it explains the 'what') & I'm not sure how to translate the info to a 'how', ie, when in the field. I use manual focus & AF depending on the scene & I need to know how to factor in the distance scale when focusing.

Can anyone point to a good source of info on this topic, for an enthusiastic novice?

PixelStan77 Loc: Vermont/Chicago

Go to"
https://tokinalens.com/product/at_x_116_pro_dx_ii/#specifications

Then on left side you can download the instruction manual for your lens.

Grahame Loc: Fiji

The first thing I would recommend is that you become conversant with the DoF (Depth of Field) for this range of wide focal length. You can see this in any of the DoF Calculators available for free and will soon see that at 'average' apertures say f/8 the DoF is very large.

The distance markings on the lens may 'possibly' only go up to 3 mtrs and may also not be extremely accurate, but 'possibly' as accurate as you could guess the distance of a subject in front of the camera.

Where the distance markings can be extremely useful is when shooting scenes with close foreground objects, e.g. a close rock on a beach of a seascape after sunset and the light is too poor to AF or manually focus with any certainty. If you practice and experiment with the lens say at 1m, 2m and 3m distance markings against known distance subjects you can confirm accuracy and build confidence in what is achievable with respect to near and far items being in sharp focus.

dione961

Awesome - thanks!!

dione961

Hi Grahame, thanks for your post - it's much appreciated. I think maybe I'm a step or 2 backwards from your guidance though. What happened is I bought 2 lenses that each have a scale & not knowing what it's for I looked up the one thing on the scale I'd read about - infinity & hyper-focal range. Then, thinking I knew what to use that for I set the Tokina to infinity & went shooting on a beach where there are giant spruce trees lying on the sand. I shot through the tree roots down the length of the trunk to a creek (mid ground) with a background of a hillside in sunshine.

I couldn't get an AF lock on anything I wanted so I manually focused on the very tip of the trunk out by the creek edge. It sounds dumb when I say it now but I thought everything would be in focus except maybe the roots right by the camera. In the resulting image the only thing in focus is the hillside, some 250 yards from the camera.

So I'm confident I'm clueless - total beginner! I will practice your suggestions BUT I don't understand what I'm practising - what the scale is saying!! Eg, if I set the scale to 5m, is it saying an object out at 5m should be in focus (assuming I focus properly), and if so, would everything else be blurred?

So I was looking for a resource to learn about lenses & how to use them correctly. For instance I have a Sigma 17-70 that also has a scale on it, with a ring with a grip on it, I guess to set the scale, but which doesn't turn. So I guess it needs me to do something else 1st. And even if I can set a scale I don't really understand why to do so!!

I've been looking for a resource on basic how to's for months but no luck. I have books on exposure, composition, DOF, PSE, the D7200 itself, & generally taking good pics, but nothing on basic use of lenses for example, or on how to light a subject (another huge hole in my skill set). UHH is awesome for the generosity of its members, like yourself; I love it. But I struggle to frame questions in a useful way!!

User ID

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Distance scales on modern lenses are basically
decorative, or "market trim". They are sparsely
marked, inaccurate, and nearly useless. Ignore
it and pretend it goes away.

Maybe you've never seen the scales on classic
pre-AF lenses. Those are real, complete, and
useful. Modern scales are just "reminders" of
the old, real scales to suggest that the lens in
hand is a "serious tool".

.

Grahame Loc: Fiji

Hi Dione,

Let's take your 5m scale marking above as an example.

Theoretically, if the marking is accurate, if you set the lens on the 5m mark it will set the 'focus plane' (plane of sharpest focus) at 5m from the camera. There will be a distance both in front and to the rear of that 5m plane that will be acceptably sharp. This depth of 'acceptable sharpness' is what we refer to as DOF. This depth of sharpness, from the nearest to farthest distance varies with the aperture you use. The smaller the aperture (diaphragm opening) the greater the overall depth is.

So taking your example of 5m, if we look at a DoF calculator for say a 16mm focal length at f/8 on a full frame camera everything from 0.88m in front of the camera to infinity will be within acceptable sharpness.

You can use this calculator to confirm and see the various DoFs at different apertures and subject/focus distances. http://www.dofmaster.com/dofjs.html

About the only time you would need to be considering to be setting 'infinity' is if you are looking for maximum sharpness for stars and using the marking is somewhat hit and miss. In addition, hyper-focal distance (the usefulness which is often questioned) is all very good but I have not yet met anyone that can estimate distances accurately.

P.S. Re-reading your post. The distance scale on the lens is adjusted either by you manually turning the lens barrel (manual focus) OR the AF (auto focus) adjusting the lens. It is simply an indicator of the distance from the camera the lens considers it is 'focused' at. I'm wondering if you are overthinking things, it is very rare for me to ever take any notice of what the 'distance scale' indicates on the lens other than in the situation I previously mentioned where there is inadequate light to AF or Manually focus so you need to set a distance.