Sunny Day + Requiring Slow Shutter or High ISO and Picture Sharpness

[AdamIsMyName]

1)Is it normal to have the camera require a shutter speed much less than 100 when set on ISO100 and shooting outside on a very sunny day (not in shade) ??

2) Is it normal for handheld photos, of trees for example, taken at shutter speeds of 400+, even 1000 at ISO100 and F2.8(or at any) to look out of focus?



IMG_8759 by adamismyname, on Flickr

2.8 ISO100 Shutter 1000

3) When taking a long exposure (20+ seconds) is it normal for the photo to end up with significant noise and appear not very sharp, even with ISO100 F32 and a tripod and trigger to set the shutter, when it looked sharp and focused before releasing?

 

[Buckster]

1. Depends on what the photographer is trying to achieve. It's VERY common with waterfalls, for instance. If you mean other than as a creative choice; That is, the camera underexposes otherwise, that would depend on the aperture.

2. Depends on how much the tree is moving, how much the photographer is moving, the quality of the lens, the quality of the sensor, the mode being shot in, whether the lens is at it's maximum aperture and focal distance for it's best capabilities, whether the photographer has nailed the focus on the tree itself, whether the DOF will capture all the parts of the tree in focus that the photographer intends, whether the lens is having problems with focus and needs to be dialed in with an adjustment.

3. Depends on the camera's capabilities. Some handle long exposures better than others. Especially on older or lower-end cameras, noise is often introduced by heat generated by the sensor during long exposures, regardless of the ISO or aperture used, and regardless of the tripod or trigger being used. Newer and higher-end cameras handle such issues much better, in general.

 

[TCampbell]

Outdoors in "full" sun (no clouds) and the sun high in the sky (not early morning or late evening) then use can use the Sunny 16 rule: f/16 and shutter speed set to inverse of the ISO. E.g. if using ISO 100 then shoot at 1/100th (or 1/125th). You can use any equivalent exposure as well... e.g. if you open the aperture up to f/11 you could bump up the shutter to 1/250th. At f/8 you could shoot at 1/500th.

I would pick an aperture of f/8 or higher (f/11, f/16) for two reasons: (1) lenses are sharper at the middle f-stops and (2) depth of field is broader. You're shooting a large-ish tree at f/2.8. It's hard to judge the real size of this tree from your photo but it looks like it might be about 20' across. At a shooting distance of 100', the DoF would be about 33' wide. But at 50', the DoF is only about 8'. It's just too shallow.

Oddly... the image doesn't look like it belongs to the EXIF data represented in the image. It says you used a Canon T2i, 100mm lens, f/2.8, and 1/1000ths. It does look like a sunny day -- maybe a little hazy. That means you should be able to shoot Sunny 16 or 1 stop down (e.g. f/11 instead of f/16). You shot at 1/1000ths which is just over 2 stops faster... meaning you could bring the camera down to f/8 or *maybe* f/5.6. And yet here you are at f/2.8. The background *should* be more blurred and the image should be heavily over-exposed. That's what I mean by the image doesn't appear to belong to the EXIF data I'm reading. Were you using some filters (a polarizer perhaps -- that might be cutting 2 stops of light??)

If you're in "full" sun, you can use the Sunny 16 or any equivalent exposure. If you have "light" overcast (this is overcast where the clouds are so thin that you can still see your shadow) then you can back the f-stop down to f/11 (or any equivalent exposure). In medium overcast (you can no longer see your shadow, but it's not "dark") you can drop another f-stop. And in heavy overcast (looks stormy and threatening) you can drop another stop yet. Your shot appears to either be true "full", but might qualify as "light" overcast due to what appears to be haze.

In answer to your questions:

1) Not normally. On a truly "full" sunny day, at ISO 100, it is not normal to need shutter speeds slower than 1/100th unless you are shooting at f/22 (they you could drop to 1/50th or 1/60th).

2) Yes. f/2.8 is a fairly shallow "depth of field". When you're shooting a tree and you want the whole tree in focus from front to back, use a higher f-stop. A shutter speed of 1/500th will typically freeze the action even if it's really blowing hard. In a gentle breeze you could get away with a slower shutter. But in full-sun, if you go from f/16 down to f/8 (2 stops) you *can* raise the shutter speed up to 1/500th and get away with it at ISO 100.

3) To shoot full sun at ISO 100 at f/32 and a 15 second exposure would require a 9 stop ND filter. If you weren't using any filter at all then what would be normal is instead of seeing image noise, you should just get a pretty much blown out white frame from a horribly over-exposed shot. If you want to gets lot of motion blur (usually with water) then you could use a 10 stop filter (nobody makes a 9 stop filter, although you could stack a combination of other filters to get there.) But at 10 stops you can't actually see through the camera to focus. Usually you have to focus with no filter, put the lens on manual focus (so that it doesn't try to refocus), put the filter back on and take the shot. Oh... and you'll need a very SOLID tripod. Nothing flimsy. The wind will put enough vibration on the tripod to result in an out of focus shot on an exposure that long.

 

[AdamIsMyName]

Thanks for the info

I am aware of the motion blur with the slower shutter (with water, clouds, etc.) and have a couple ND filters I use for that.

Yeah, I had a B+W circular polarizor on the lens when I took the picture of the tree, the lens is the canon 100mm macro 2.8 manual mode The camera is a Canon T2i

Main reason I was shooting at such a high shutter for the tree picture was because I figured it would cancel any camera shake on my part, but I guess in turn I cancled out my dof

Regarding question 3, I should have clarified that it was in regards to shooting stills indoor with longer shutter to compensate for a lack of lighting, with the camera set to ISO200 (mistake on my part - thought I had it set to 100 as I usually do) and on AV mode. I was selecting F32 - the highest the lens would go - assuming that the entire object would then be in focus? The result just doesn't seem crisp and appears noisy to me.

So a guess a better question would have been - does shooting at long shutter speeds to compensate for lack of light generally create a noisy photo even at ISO100

The maximum aperture is not the best to select for the sharpest photo (as in, having the widest area of sharpness) but instead the middle range?

I'm guessing that F32 may not have been

IMG_9337 by adamismyname, on Flickr

This photo I took F10 1/125 100ISO with circular polarizor attached, manual mode, handheld. Very sunny, no clouds, around noon. Does it seem to be sharp enough, overall?


IMG_8965 by adamismyname, on Flickr

 

[enzodm]

Too small apertures (i.e., too large aperture numbers) cause a reduction of resolution due to diffraction. In a crop factor camera, it seems that the phenomenon starts at f/11.
Regarding noise, there is the possibility that very long exposures cause some extra noise. However, Canon has a long exposure noise reduction option, that acquires a black frame just after your shoot, and subtracts it from the original image (look at it in the manual). The total time will be the double.

It is difficult to recognise sharpness problems on small images. Try to upload a 100% crop of an area, to see it at pixel level.

 

[AdamIsMyName]

Thanks for the info,

If you click that flicr link below the image it will take you to where you can select to view it at 100% size byu clicking the image in flicr, or the + between prvious and next, and then view all sizes at the top right

 

[TCampbell]

Main reason I was shooting at such a high shutter for the tree picture was because I figured it would cancel any camera shake on my part, but I guess in turn I cancled out my dof

There's a simple guideline for finding a safe shutter speed for hand-held photography. Assuming you don't have image stabilization in the lens, the guideline says that as long as the shutter speed is set to 1 / (focal-length) x (focal ratio) then you shutter speed should be fast enough that you won't get motion blur in the image while shooting a hand-held shot. This assumes you are actually trying to be steady, using good technique for holding the camera, and an average person (you aren't particularly shaky). Your T2i has a 1.6 crop factor (that's a constant). So with the 100mm focal length, you would have needed a shutter speed of 1/160th or faster. Notice that that's quite a bit slower than the 1/1000th that you used.

Regarding question 3, I should have clarified that it was in regards to shooting stills indoor with longer shutter to compensate for a lack of lighting, with the camera set to ISO200 (mistake on my part - thought I had it set to 100 as I usually do) and on AV mode. I was selecting F32 - the highest the lens would go - assuming that the entire object would then be in focus? The result just doesn't seem crisp and appears noisy to me.

So a guess a better question would have been - does shooting at long shutter speeds to compensate for lack of light generally create a noisy photo even at ISO100

Not usually. The "noise" is usually the result of using a very high ISO speed -OR- having a high temperature in the sensor (physical temperature sensor being high can also contribute to noise.)

It's good that you understand that higher f-stops will increase the depth of field. But you don't have to go crazy with the aperture (more is not necessarily better.) Lenses are often the very sharpest at the middle f-stops. So if you don't need more depth of field than you already have, why crank the f-stop any higher?

Old cameras usually had a depth-of-field scale on the lens that showed you what the focused range would be. They usually don't include these anymore -- especially not on zoom lenses, but you do find prime lenses that still have them. You can use a website such as DOFmaster.com to look up the DOF (they even have downloadable apps for smartphones... and I seem to recall there are a few free smartphone apps that have DOF calculators as well. You enter the type of camera body, lens focal length, f-stop you're using, and the focused distance and it'll tell you the DoF (near limit and far limit for acceptable focus.)

ALSO... since you have a T2i, you have a DoF Preview button on your camera. Just below the button you press to release the lens, there's a black button. If the camera lens were pointed at your, this button would be on the front of the camera in the lower right corner -- very close to the logo in the corner. If you press that button while looking through the camera, the aperture blades will stop down to the aperture which will be used when the camera is taking the shot (you must be in a mode other than the fully automatic mode). Also if a flash is attached and on (or if you raise the pop-up flash) that same button will activate the "modeling light" function of the flash instead of acting as a DoF preview button. BUT... if you use that button you can get a pretty good idea how how much of your image will actually be in focus when you take the shot.

The maximum aperture is not the best to select for the sharpest photo (as in, having the widest area of sharpness) but instead the middle range?

I'm guessing that F32 may not have been

IMG_9337 by adamismyname, on Flickr

The middle apertures typically exploit the very best optical quality of a lens. If you have a zoom lens you may also find that certain focal lengths are generally sharper than others (this varies by lens -- there's no "generalization" that I can make other than it's usually not uniform.)

DoF naturally gets broader as the subject distance gets farther. That means that when shooting really really close-up shots at low f-stops, the DoF can get paper-thin... so thin that it's not possible to have a whole subject in focus even if the subject is pretty small. Because of this, you usually want to pick higher f-stops when shooting close up so that the DoF is at least broad enough to get your whole subject in focus.

There's an optical concept due to the wave nature of light (the fact that light is a waveform ... essentially a wiggling beam of light and not a straight beam of light) which hits a point where the camera becomes "diffraction limited." I don't want to scare you into thinking high f-stops are bad per se. The DoF will continue to increase, but you can get to a point where it is no longer possible for an image to appear sharper than it already is once the camera becomes diffraction limited.

There's a tutorial on here if you're interested: Diffraction Limited Photography: Pixel Size, Aperture and Airy Disks

Essentially this means that it's no longer possible for a single "point of light" (if I may be so careless with terminology) to land on a single "pixel" of the sensor (really it lands on clusters of "photo-sites" - sensors don't have "pixels"). As a result, it is no longer possible for one "pixel" to maintain one color and an adjacent pixel to maintain a completely distinct color. They will start to blend together. It's as though someone is reducing the resolution capabilities of your camera.

But before you swear off ever using anything above f/11... keep in mind that you already throw most of your cameras resolution away. If you were printing full size at 300dpi, that'd be a pretty good sized image. And on a monitor at 72 dpi you need to stack up a number of monitors to create a small "video wall" to see your images in full resolution. So you would't necessarily notice that the camera is diffraction limited at high f-stops unless you were printing very large output sizes -- which few people do.

 

[enzodm]

Thanks for the info,

If you click that flicr link below the image it will take you to where you can select to view it at 100% size byu clicking the image in flicr, or the + between prvious and next, and then view all sizes at the top right

Checked on Flickr; unless they are cropped by you, in fact they are not at 100% (just 2048x1365). However, in the first one even at that size there is a clear sharpness problem; not sure about noise, but is less relevant. More difficult to tell something on the latter.

 

[AdamIsMyName]

Thanks for all the helpful info.

Ah yeah enzodm your right, didnt crop it, but didnt realize that it wasnt 100% and instead cropped to by flicrs to its own sizes.