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08/08/2010 07:22:02 AM · #1 |
First I would like to say thanks to anyone who takes the time to read this long post.
I've been struggling with my D70 lately. Exposures seem poor, and I can't focus for the life of me. It almost never wants to focus on the appropriate subject it seems. I don't claim to be a photography expert but I've owned my camera for 6 years and I feel like it could be getting worse, although sometimes I feel it's in my head because I DO have many that come out okay. It sometimes seems to be hit and miss even though I'm doing the exact same thing. Pictures just never seem to be as sharp as they should be. I've seen some amazing photos taken with a D70 and mine never seem that crisp.
First my equipment:
D70 and 8 year old AF Nikon f3.5 24-120mm zoom.
Now the following exhibits:
Exhibit 1: Exposure issue:
Photo taken at light meter suggestion: ISO 500, f5.6, 1/250
Photo taken at what I feel is a more correct exposure: SIX clicks over exposed: ISO 500, f5.6, 1/80
Exhibit 2: Focus issue. I have always thought the best way to focus on my subject was to zoom in, focus and zoom out. But as these pictures will demonstrate, that may not be the case. I did a test using the three focus modes.
SINGLE AREA FOCUS: Zoom in, focus, zoom out
SINGLE AREA FOCUS: Zoomed out focus
DYNAMIC AREA FOCUS: Zoom in, focus, zoom out
DYNAMIC AREA FOCUS: Zoomed out focus
CLOSEST SUBJECT FOCUS: Zoom in, focus, zoom out
CLOSEST SUBJECT FOCUS: Zoomed out focus.
As you can see the ONLY picture that focused correctly on my closest subject (the flowers), was the last one using "Closest Subject" mode, focusing zoomed out.My first conclusion naturally, is that zooming in and focusing does NOT work with my lens. Secondly as for the focusing settings, I don't know. Is this normal? Will Dynamic Area focus on the background instead of forground? And shouldn't Single Area focus on the main subject as well? Someone please enlighten me on both my exposure issue and focus issue. I'll be the first to say it could just be me but I'm tired of hit and miss photos. I have many photos that look great, but there are also many that I THOUGHT were going to look great and just turn out to be focused in the wrong area. Thanks a MILLION in advance!
Message edited by author 2010-08-08 07:30:26. |
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08/08/2010 07:57:28 AM · #2 |
Regarding the exposure "issue" - that's a tough shot for any camera. I think that what your camera did was underexpose as much as it could without clipping the shadows in order to "save" as much of the highlights as possible.
It's a strategy all of us should learn - underexpose to save highlights. The camera will tend to clip highlights easily, but always keep a bit of shadow detail. So people underexpose to keep highlights in check, because even the deepest shadows will tend keep some detail... then, use curves to bring up the midtones.
If you look at your first image, which is "6 clicks under" (-2 EV) compared to the second, it STILL doesn't clip the shadows... but you gained some highlight detail.
ETA: I bumped up the midtones & shadows quite a bit in this edit of the first shot, and it looks a bit more contrasty than your "6 clicks over" shot, but with the same amount of shadow detail (no clipped shadows), yet with a bit MORE highlight detail, because there was more highlight detail there in the first place:
The zoom-focus-zoom issue: Most lenses DON'T hold focus when zooming. Especially new ones. So zoom first, then focus. The D70 should focus accurately enough to not require zooming in first. Had you been using MF with a lens that held focus (like most of the push-pull lenses), it wouldn't be an issue, because they hold focus so that you can zoom in and set the focus super-accurately first... new lenses don't hold focus because they're made to be used with the new AF cameras that will focus better than we can manually, at any focal length. With AF, there's no more need to zoom first, then focus.
Message edited by author 2010-08-08 08:15:38. |
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08/08/2010 10:52:29 AM · #3 |
With regard to exposure, there isn't all that much to be said that  George didn't cover. I'll just add that you should keep in mind that the camera is trying to make the area under the selected metering point(s) mid-gray. So if you are spot-metering, your subject will always be smack dab in the middle of the tonal range. If you have multi-point metering set, then the camera will make the best decision it can about keeping everything it is metering on within the tonal range available. In your first example, the strong backlight no doubt drove the camera to reduce exposure.
With regard to focus, what George was talking about is the fact that most consumer lenses (and even some professional ones) are not "parfocal," meaning that they don't necessarily hold focus while zooming. Zoom first, focus, and shoot. |
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08/08/2010 12:15:23 PM · #4 |
| Thanks for the great advice guys. I guess I'm still a little confused with the focus issue though. I'm clear that I shouldn't zoom, focus, then zoom out. But I posted examples where I didn't zoom. I just stayed wide, and shot and the ONLY setting that focused correctly was the last one. Why wouldn't Dynamic, or Single Area be focusing on the flowers which are clearly the subject in the foreground? As you can see the camera want's to focus on the furthest background in ALL scenarios except for the last.... |
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08/08/2010 01:16:04 PM · #5 |
| I don't let the camera choose the focus point for me. The camera makes it's best guess as to the subject, but it's still a dumb machine. I focus using only one focus point, usually the central one, locate it on the subject and then recompose a bit if needed before depressing the shutter button completely. |
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08/08/2010 01:16:50 PM · #6 |
Originally posted by nateconnella:
Thanks for the great advice guys. I guess I'm still a little confused with the focus issue though. I'm clear that I shouldn't zoom, focus, then zoom out. But I posted examples where I didn't zoom. I just stayed wide, and shot and the ONLY setting that focused correctly was the last one. Why wouldn't Dynamic, or Single Area be focusing on the flowers which are clearly the subject in the foreground? As you can see the camera want's to focus on the furthest background in ALL scenarios except for the last.... |
Regarding exposure, here's an exerpt from a PM to another member that may explain in more detail what's happening; bear in mind that the exposure meter is just there to provide raw input, and the input needs to be interpreted. To some extent the camera can be set to do that, but you can do it better yourself.
Originally posted by PM_Bear_Music:
Yes, the camera's meter looks at whatever it is "told" to meter and gets a luminance reading off that spot or that area. However, the camera doesn't "know" if it's pointed at a white wall or a black wall, so it doesn't know if it's "seeing" a very weak light reflected off a bright surface or a very strong light reflected off a dark surface. Accordingly, it makes the assumption that the average of all the surfaces it is metering is "Zone V", 18% gray.
By way of experimentation, if you were to place a white cardboard and a black cardboard side-by-side on a vertical surface, in the same light, and shoot them, this is what would happen if you used the camera's "interpretation" of "correct" exposure:
1: shoot a frame filled with the black card.
2: shoot a frame filled with the white card.
3: shoot a frame that is half black and half white.
In theory, 1 & 2 would be identical, neutral gray renderings, impossible to tell apart, and 3 would be accurately rendered with true white and true black. To whatever extent this is NOT true, it is because the camera algorithms on metering are more sophisticated (usually in terms of "weighted" metering) than this test can show.
So, in practical terms, what this means is when you shoot a predominately bright scene you need to add 1-2 stops of exposure (1-2 EV) to compensate or the scene will be underexposed. Likewise, when you shoot a predominately dark scene, you subtract 1-2 stops (1-2 EV) or the scene will be overexposed.
Regarding "stops" vs "EV", which is the appropriate term depends on how you are using your camera. If you are using Av or Tv mode (aperture priority or shutter priority) then you use the EV Compensation slider (visible in the viewfinder) and, usually, (it depends on whether you have reassigned controls in custom function menu) the big wheel on the back of the camera to move the pointer left or right. If you are shooting manual mode, the viewfinder slider works like an old-school light meter slider, and you can adjust either shutter speed or aperture (or both, of course) to move the pointer on the scale.
In general, for everyday shooting, I keep my EV compensation at minus 2/3 stop, which seems to work well for me as an average.
But in any case, your primary skill to be acquired in metering is to get a feel for what's actually BEING metered, and to learn to reframe scenes during metering so that you are metering the critical elements, then to *interpret* the deviation-from-18% of what you've metered and compensate exposure correspondingly. Or, of course, set your camera for automatic bracketing :-)
In Zone System terms, we find the critical components of the scene, meter them, and "place" them on the correct zone; so if I metered, say, a snowy slope on a mountainside and wanted to have luminous detail, I'd want it rendered on Zone 6.5, say, and I'd give +1.5 EV exposure. If I metered a shadowy area on the side of a building and wanted it to be dark but fully detailed, I'd want it at Zone 4 and I'd give -1.0 EV. |
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Regarding "zoom in, focus, zoom out", that only works on lenses that have follow focus capability, and yours is assuredly not one of them. Follow focus on zoom is only present in constant-aperture zoom lenses, and even on most of those it does not work very well, unfortunately. So you have to refocus every time you zoom.
Regarding "Why wouldn't Dynamic, or Single Area be focusing on the flowers which are clearly the subject in the foreground?", my question to you would be, "Why are you relying on the camera to make these decisions?" That's very weird, from my perspective. What most of us do is choose a focus point that is over the area we want in focus, choose it manually, and let the camera focus, OR use center focus, frame up with the center over the subject, depress shutter halfway to lock focus, then reframe with shutter depressed and shoot, OR go with manual focus.
Those shooting sports and other fast-moving things learn to use the tracking focus on their cameras, and that can be very tricky, but rewarding.
R.
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08/08/2010 03:17:45 PM · #7 |
Originally posted by Yo_Spiff:
I don't let the camera choose the focus point for me. The camera makes it's best guess as to the subject, but it's still a dumb machine. I focus using only one focus point, usually the central one, locate it on the subject and then recompose a bit if needed before depressing the shutter button completely. |
I just learned myself how to set the focus point on my camera! This is what I do now too! Find it works for me!!
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08/08/2010 03:37:38 PM · #8 |
| My focus point was set to right of frame and I didn't know how to change it. Now I do. You have no idea how helpful you guys have been. FINALLY I think my camera will focus where it's supposed to. The darn focal point was SET to the side of the frame. No wonder it wouldn't focus in the middle. I feel like an idiot! More tests tomorrow when it's light out. |
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08/08/2010 03:40:16 PM · #9 |
Originally posted by nateconnella:
My focus point was set to right of frame and I didn't know how to change it. Now I do. You have no idea how helpful you guys have been. FINALLY I think my camera will focus where it's supposed to. The darn focal point was SET to the side of the frame. No wonder it wouldn't focus in the middle. I feel like an idiot! More tests tomorrow when it's light out. |
You aren't an idiot. I've done exactly the same thing by accidently scrolling the focus point. Luckily I noticed after a few shots and restored the focus point to central, but at least I learnt how to move the focus point when I wanted to...all without reading the manual:)
Message edited by author 2010-08-08 15:40:38. |
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08/08/2010 06:03:15 PM · #10 |
Originally posted by nateconnella:
My focus point was set to right of frame and I didn't know how to change it. Now I do. You have no idea how helpful you guys have been. FINALLY I think my camera will focus where it's supposed to. The darn focal point was SET to the side of the frame. No wonder it wouldn't focus in the middle. I feel like an idiot! More tests tomorrow when it's light out. |
Dont feel like an idiot! I did the same thing... thats how I learned. I ended up reading the manual to find my answer you asked here lol we both had to find help... it works!
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08/08/2010 06:22:55 PM · #11 |
| Trust me, even after owning it for 7 months, the D90 can still make me feel like a complete noob. And yeah, that scrolling focus point helps a ton! :-) |
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