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Maintaining focus on the *entire* photograph area


phoenix_kiula

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Hi I have a d300 with the usual 18-200 VR lens. I am shooting at wide angle (18mm?) -- without the lens out of

its position at all -- and getting the full visible scenery in viewfinder. But in these cases, there is still

some focus somewhere, a tree, or a rock, or something, and the rest is blurred. This effect is great when I wish

to focus on something, but it's a big disappointment when I come home and see an entire mountain or lake

completely blurred with one stupid tree in focus.

 

I know I am missing something here. I use my camera in the shutter "S" mode, because this helps me most with low

lighting (I do a lot of night photography). Should I be shifting to aperture "A" mode instead, and setting "f" at

something like "f22" so that the widest possible area is in focus? This is what I have gathered from reading some

websites and the "Understanding Exposure" book, but I'm not sure.

 

Also, when I have "A" mode and I am selecting aperture, how should I set manually the shutter speed? Or will I

have to let D300 select the shutter speed automatically? Thanks!

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Thanks James. I am trying to become better at the "A" mode.

 

My question:

 

(1) is it possible to be in "A" mode and still manually set the shutter speed?

 

(2) is it better to use the "continuous servo" mode instead of the "single servo" mode?

 

I'm speaking specifically of d300. Thx!

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To supplement James' response, also look up the phrase 'hyperfocal distance'. If you are not doing so already, you may want to consider the bringing a tripod into the mix. The moral of the story is that you are probably going to need/want to stop down your lens. This will lead to longer shutter times (whether you set it manually or not) and you are going to need to keep you camera rock-solid during the exposure. VR will help, but it is no match for a good tripod in this situation.
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Phoenix,

 

Thom's book, which I have not seen, is more likely a user guide for a camera rather than a photography manual. Look at this http://www.luminous-landscape.com/tutorials/understanding-series/dof.shtml to start with and then read around the subject. When you set a small aperture you can press the preview button and you will see the out of focus backgound/foreground suddenly come into sharper focus

 

In landscape photography, broadly speaking, depth-of-field as controlled by aperture and focus is usually much more important than shutter speed (as you often want everything in focus) and the two are mostly irreconcilable. Using a small aperture means long exposures which may entail blurring of movement and degrading the image through diffraction; using a wide aperture means you get shallow DOF but no movement. You can get around this with filters/changing ISOs/camera or lens movements but the subject is pretty large.

 

As Scott said if you don't use a tripod then you are really going to need one to be able to take a lot of landscape shots. The best thing to do is read about DOF, look at good landscape photos and above all try it a lot!

 

James

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To help you learn depth of field turn off AF, and shoot in manual focus. That way you determine what you are focusing on. The actual focal point of the image has a great bearing on the total range of focus in the image. Once you have grasped this, you then can switch to AF if you must, but then you have to move the AF point to the right location. I often forget this last step, so my best practice is just use manual focus, but that is me.

 

Use aperture priority. A larger the f stop, like f 11, the smaller the lens opening and the greater will be the depth of field. But the shutter speed will be lower. So use a tripod. It is a must. I would try and take my shots at 20mm and not 18mm to avoid any possible distorsion.

 

Also research diffraction at Luminous landscapes. Large f stop numbers like f 22 (small openings) give good depth of field, but sharpness suffers! Until you master the concepts and learn the specific parameters of your 18-200mm lens, I would use f stops between f 8 and f 16.

 

Joe Smith

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Put the camera on P mode. Rotate the main command dial and the camera will pick different combinations of aperture and

shutter consistent with ISO selected and light available. The exposure will all be correct or at least the same.

 

The closer to f22 you are, the more will be in focus. The closer to 4.0, the less will be in focus.

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Phoenix, I have the D300 and Hogan's eBook so maybe I can offer some help.

 

Generally, if you have a deep landscape with something in the foreground and mountains in the background -- and you want all of it in focus -- you want an aperture in the f/8-11 range. That's why I usually use Aperture priority, not Shutter priority. As said, a tripod is a huge help because your shutter speed will be slower. A suggestion, also remember to turn off the VR when you use a tripod and a cable release as well as mirror lock-up or at least Exposure Delay is very helpful to minimize vibration.

 

If you are basically setting the aperture and shutter speed yourself, use the M (manual) mode instead. Until you know what you are doing, this will give some funky results but it is a way to learn.

 

Hogan's book is great for helping you with settings that work well with the D300 but he assumes you already know about photography. You might want to look into doing some reading about landscape photography. Libraries are great for free stuff and there are many online tutorials available. Amazon, of course, offers dozens of books as well.

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Thanks so much Joseph, James, and Bruce.

 

I have been playing around with my tripod, no VR, and even manual focus, but I have some questions.

 

(1) Where is mirror lockup? Is this a menu setting or some button needs to be pressed?

 

(2) I am trying A mode on d300. When I rotate the black wheel to the right in this mode though, nothing changes, and in the viewfinder I keep seeing "f3.5". Aren't the aperture and this f-value (or "f-stop"?) related directly? How does one change the aperture or the f-value in the A mode?

 

Thanks so much for bearing with me.

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Oh, the f-value is set from the FRONT dial/wheel! Duh.

 

Ok, so now I am setting it at f11. Looks like I still need to play with A values and even so, the shutter clicks, then waits for what seems to be an eternity (sometimes up to 10 seconds!) and then clicks. Once or twice, I keep waiting for 20 seconds or so and it still hasnt clicked. Is this normal?

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Learn about depth of field. An old used film camera book is just as good at describing this as a modern digital photography book.

 

Shoot in aperture priority mode. Adjust to a fairly small aperture like f16 or f20 using the front dial on your D300. Set the ISO sensitivity auto control to ON.

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Is that long time normal? Yes, if it's kinda dark.

 

I am going to try to make this easy to understand. I hope it works! Your camera has to get a certain amount of

light in order to make a picture. Doesn't matter what kind of camera you have, they all have to have a certain

amount of light to expose a picture. The camera can get that light one of two ways: either it can expose for a

long time, or it can open up the lens "hole" (aka aperture) to let in more light. When the hole is large, you

are at a low-number f-stop (e.g. f2.8). F2.8 would mean that the lens is open 1/(2.8) amount, or nearly

one-third of the way open. When the hole is small you have a high-number f-stop such as f22. F22 means the lens

is open 1/22 of the way. It's a really, really tiny "hole" or aperture. If your lens is only letting in that

tiny amount of light, the exposure has to be longer in order for enough light to get in for your picture. Maybe

a lot longer. Make sense?

 

The thing is, when the lens is really open, and letting in lots of light, it makes the image fuzzy except where

you put the focus - the more open the hole, the more stuff will be fuzzy (or, the shallower your plane of focus

will be). So, f2.8 will ALWAYS be fuzzier than f22. But you have to remember that f22 requires a lot more time

to make the picture, and after a while, your hand might start to shake holding the camera. That is why you need

the tripod - it won't shake. The "mirror lock" also has to do with camera shake, but try the tripod first.

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Phoenix,

 

I would recommend buying a good book on basic photography and reading with camera in hand. Read it as many times as you need till you understand what they are saying. I learned a lot from a book called "Photography" by Barbara London. The edition I have (7th) has a lot of film stuff in it but the basics of a camera and lens and how they work together are the same whether you are shooting film or digital. This book does a good job of explaining things in a very simple way with lots of illustrations.

 

Good luck,

Catherine

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Phoenix,

 

Jennifer has given you a good simplified explanation of what you need to know. The is only one mistake: at f/2.8, the aperture is not "roughly 1/3 open", that is essentially meaningless. The aperture is actually open an amount equal to the focal length divided by 2.8. For example, if using a 28mm lens at f/2.8 your "hole size" will be 28/2.8 = 10mm (1cm). So it's not really the diameter of the hole that's crucial, it's the RELATIONSHIP or RATIO of it's size to the focal length that's important.

 

Hope that's clear :-)

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Thanks so much everyone, esp Jennifer.

 

I am reading up on DOF. Makes sense. Looks like this is exactly what I was describing as "focus all over" (high depth of field).

 

But I am not sure d300 is making things any easier for me.

 

Two things I tried, with tripod this time, and using timed release:

 

1. First as a base to compare things with, I took a pic with "P" mode. Of the entire landscape in front of me. It makes quite an alright guess: chooses F8. Exposure is too much (it's sunny right now) but with -1.0 it looks acceptable.

 

2. Now I try to take it in the "A" mode. Set the F at F11. I have a tripod. Don't care about how long the shutter takes. But it's still not as good as I want it to be!

 

Clarity in both 1 and 2 seems the same, not very clear in either case. I am even using the tripod now and it's not very windy, so the camera is being pampered with the best conditions really afaik.

 

What else can I do to improve "focus" as I called it earlier, but I now mean clarity? How can a picture with high DOF be made clearer?

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You probably still don't have enough DOF to satisy you at f/8-f/11. Realistically, as far as the eye is concern on moderate sized pictures (say up to 16-20 inches), loss of image quality due to diffraction won't be too noticable at f/22. Try taking the picture at around there and see what you get. Make sure the image quality on the camera is set to highest resolution too.
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