Focusing on the moon

[Wickham]

It was a lovely clear night last night and I took a photo of the moon with my Olympus C770 and TCON17 telephoto lens.

It came out unfocused and I tried to find a setting where I could set the focus to infinity but couldn't find it. It seems that manual focus means finding something else, pressing the button half-way down to fix the focus, then moving onto the target.

However, it was pitch black everywhere so there was no way I could fix the focus on something else.

How could I focus on infinity? Is the default setting supposed to be infinity because it didn't appear to be so?

[RAH]

What you describe is not manual focus, but a technique you might use if the object you want to shoot has no strong vertical edge, so the camera won't focus on it. So you find something else at approx the same distance that the camera WILL focus on, focus on it by holding the release haf-way down, then reframe the shot to what you want to shoot while still hold it down, and then depress it fuly to take the picture.

You can also use this technique to pretty much eliminate the shutter lag which everyone complains about. If you prefocus on something and hold it down until exactly the moment you want to take the picture, and then depress it fully, there is essentially no shutter lag.

Anyway, to go into real Manual focus mode (and then set it to infinity), assuming the 770 is like my C-730 and C-750, you have to follow a sequence that can be a little tricky.

1) Depress the OK button and HOLD IT for about 1 second.

2) A vertical scale should appear (on the 750 it's on the left side of the screen). Below the scale are letters that say "AF/MF", with "AF" selected. The tricky part is that you have to first press the left/right buttons to SELECT "MF".

3) When you select "MF" by pressing the left/right buttons, the scale activates and you can use the up/down buttons to move the focus slider on the vertical scale. Infinity is at the very top, as you might expect. There is an infinity symbol there.

4) Once you have done that, press the OK button and HOLD IT for about 1 second. The scale disappears, but the letters "MF" should appear in the display.

To return to autofocus, press the OK button and hold it for until the scale reappears, use the left/right buttons to reselect "AF" then press OK button (it seems you don't have to hold it down at this point).

I have taken many pictures of the moon during eclipses using the 730 and 750 and the TCON-17, so I know it works fine. You should absolutely use a tripod to avoid camera shake. Depending on the ISO you use (lower would be better to avoid noise), you might also need to use a remote control (or the self-timer) to further avoid camera shake. To get very slow shutter speed (below 2 seconds, I think), you need to use full manual mode.

I warn about camera shake because the first time I took pictures of an eclipse with my C-730 and Tcon17, I did not use manual infinity focus. I just aimed at the moon, let the camera do its normal focusing on the moon itself (by half-depressing the shutter), and then took the picture. Most of these pictures came out sharp, so perhaps your unsharp pictures are because of shake. I do think manual infinity focus is a better way to take these pictures.

[Wickham]

Jeez - very complicated to remember when out and about!

I was resting the camera on a gate post so the shaking would have been minimised.

Very cloudy now so I won't have a chance tonight. It was only an experiment with my TCON-17 anyway.

[ceasar]

It was a lovely clear night last night and I took a photo of the moon with my Olympus C770 and TCON17 telephoto lens.

It came out unfocused and I tried to find a setting where I could set the focus to infinity but couldn't find it. It seems that manual focus means finding something else, pressing the button half-way down to fix the focus, then moving onto the target.

However, it was pitch black everywhere so there was no way I could fix the focus on something else.

How could I focus on infinity? Is the default setting supposed to be infinity because it didn't appear to be so?
May I ask if the moon was out of focus, or everexposed?
The full moon is an object lit by full sunlight, and your camera may have been trying to average the exposure with the black sky surrounding it, which would result in overexposure. To take a picture of the full moon you MUST use manual exposure and the "sunny 16 rule." If you are using 400ASA film or the digital eqivalent, then you have to set your shutter speed to 1/400th or 500th a second and you have to set your aperture to f16 or f11. Your shutter speed should be the same as your ASA rating, and your aperture should always be f16 or f11. If you increase the shutter speed you must open up the aperture to compensate for it. This is the type of shot where a purely mechanical camera with changeable f stops and shutterspeeds will prevail. It also goes without saying that the lens ahould be manually set at infinity.

Sadly, most small digital camera's won't be able to take this kind of shot, at least without torturous manipulations!

[RAH]

Sadly, most small digital camera's won't be able to take this kind of shot, at least without torturous manipulations!

However, in this case, the C-770 is fully capable of having its shutter and aperture set to whatever you want, including 1/400 and F11, plus manual focus, plus an ASA/ISO of 400. But this high an ISO with a digital camera will yield pretty noisy, grainy results, so you'd probably want to make it say 200 or even 100. The "sunny 16 rule" sounds interesting and I'll have to try it. I agree that the full moon is very bright and needs special handling.

When I was taking pictures of the eclipses, I alternated between taking light readings on the dark part (and letting the bright area "blow out") and taking readings on the bright area (and letting the dark area become black). I also did some bracketing with exposure compensation, and many pictures worked out OK.

[ceasar]

Try it at 100 ASA. I guarantee it will work. Your point to use a tripod is also well taken. If you want a sizable moon, you will need the equvalent of 400mm lens on a 35mm format. Try putting the moon into a corner of the photograph and then make a double exposure of a "moonlit" landscape on the same "negative." Let your imagination loose! Your technique on the pictures of the eclipsed moon was correct. There isn't as much contrast to deal with in that situation. Good luck.

Bob

[Wickham]

Thanks for your comments, all.

The shot was fuzzy round the edge so I thought it was a focus problem. As I said, I didn't know how to set the focus to infinity at the time so it was probably wrong.

However, it may have been aperture too. I had a 100 ASA setting but I was on my usual aperture priority setting which does not allow f more than f8 so I will try again on manual.

I was out looking at my local bat but never had the slightest chance of catching it!

PS I've just discovered that my C-770 only goes to f8, not up to f11 or f16, even on manual.

[RAH]

Yup, you're right - the 730 and 750 also have a smallest aperture of f8. I had it in my head that it was f11. However, from what I've read (I think in Popular Photography), f-stops in small-sensor cameras are not directly comparable to f-stops in 35mm cameras (just as a 200mm lens on a 35mm camera will yield 300mm equivalent on a DSLR with a 1.5 sensor factor). F8 on a 770 is equivalent to a much smaller f-stop on a full-frame 35mm camera, at least as far as depth-of-field is concerned.

One thing I don't like about aperture and shutter priority on most digital cameras is that if you exceed the capacity of the camera (e.g. when in aperture priority mode, it cannot increase or decrease the shutter speed enough to get proper exposure), all you get is red indicator numbers, so if you're not paying careful attention, you take a picture and in fact the camera cannot set proper exposure. This is MUCH less likely to happen on the 770 in full manual mode, mainly because the shutter speed can go all the way down to 16 seconds.

I understand some digital cameras in this circumstance will automatically adjust the ISO to maintain a proper exposure in aperture or shutter mode when you exceed the camera's capacilty.

[ceasar]

Thanks for your comments, all.

The shot was fuzzy round the edge so I thought it was a focus problem. As I said, I didn't know how to set the focus to infinity at the time so it was probably wrong.

However, it may have been aperture too. I had a 100 ASA setting but I was on my usual aperture priority setting which does not allow f more than f8 so I will try again on manual.

I was out looking at my local bat but never had the slightest chance of catching it!

PS I've just discovered that my C-770 only goes to f8, not up to f11 or f16, even on manual.
If your aperture only will stop down to F8, try (if your camera will let you) setting your shutter speed to 1/250 or 1/500th of a second. You will get about the same exposure as Fll or F16 at 100th or 125th of a second. Experiment a little to determine the best combination, and remember to put the camera on a tripod.