Digital Rebel - Focusing Problem

[WAL]

Hi there,

I have been using the Digital Rebel with the standard 18-55mm lens to shoot a number of bands recently.

I have been using an ISO 1600 setting at about f5.6 with a speed of 1/25 of a second shutter speed for a while and got excellent results. However, just recently, shooting at the same venue, I have noticed that the sharpness in the pictures I am taking isn’t there and I am getting quite a lot of shots that are extremely out of focus. A camera like the Rebel makes me look like the Press and as a result, I have barged my way to the front. So the distance from the subject is not a problem (although I would like a longer lens).

I am a little short sighted and the only setting I have fiddled with recently is the eyepiece to compensate for my myopia. What I need to know is, if I get a clear looking shot through the eyepiece, having adjusted for my poor eyesight, when I then adjust the focusing ring on the lens, is this having an effect upon the final picture?

I know that musicians don’t stand still and that the low light and slow shutter speed means that camera shake is inevitable without a tripod, but the photos aren’t suffering from obvious motion blur, they are simply not sharply focused.

I have taken a couple of shots with the automated settings and these are pin sharp by the way, but obviously, I prefer the manual settings in order to get all arty and clearly need help. Maybe I need to give up beer?

Anybody got an idea?

Regards

WAL

[malcolmx]

i suffer from shortsight and if you are on manual mode then you have to set the myoptic view finder to give a clear image of the small sqares you see in the view finder i have had a lot of focusing issues with my 10d but it is usually shake not optical problems

[WAL]

Thanks. I'll giveit a shot.

Regards

WAL

[Andy_T]

Wal,

1/25 is way too slow.
Get the 75$ 50/1.8 lens and take the same photo at f/2.8.
You'll get 1/100 at the same light level/ISO setting and it should make all the difference.

The 50/1.8 @ f/2.8 is also way sharper than the 18-55 @ f/5.6, only the DOF is naturally not as deep.

Best regards,
Andy

[Bodog]

From those settings, it appears that there isn't much light for the camera to focus with, but you say you were getting excellent results prior. However, AFAIK the shutter will not activate until focus is achived, so either you're getting Camera shake, motion blur, or there is something wrong with the camera/lens. Might want to check the focus in brighter light or with a tripod. Do you use multiple focus points? Could be the camera is not focusing where you think it is. Wish I could consistently hand hold at 1/25th... :D

[robertwgross]

I am a little short sighted and the only setting I have fiddled with recently is the eyepiece to compensate for my myopia. What I need to know is, if I get a clear looking shot through the eyepiece, having adjusted for my poor eyesight, when I then adjust the focusing ring on the lens, is this having an effect upon the final picture?


If we assume that your camera's autofocus system is working correctly, then the view that you see through the viewfinder has no bearing on the image captured by the sensor. The mirror causes those to be on different optical paths. If you adjust the diopter at the viewfinder, you can adjust it from perfect to blurry. So, if you adjust it for perfect, that should work. On the other hand, if you are trying to override autofocus with some manual focus dialing, then there may be an interrelationship.

---Bob Gross---

[WAL]

I think that I have sussed the problem. It's the shakes. I took some shots in the dark at another gig this week. making an effort to hold the camera really steady and leaning on something seemed to help. This was with manual focusing rather than auto focusing and the results were much, much better. I don't think that I appreciated how slow 1/25 is. I looked at the info on the earlier shots and they were taken at faster speeds because there were bigger bands with more lights. So I think I have cracked it. As regards the lens, I'm checking out the different lens options anyway, as the standard Rebel 18-55mm isn't "drummer friendly" (it won't reach). Reckoning on getting a 70-200mm.

Regards

WAL

[RAitch]

You thought you looked like the press with the kit lens? Wait 'till you slap the 70-200 on there with a hood.

[mkh]

I'm still new to my 300D but I thought that in manual mode it used the center square for a focusing point and it would turn red when you had manually focused it properly.


As for the 70-200mm, your problem will only get worse. It will get you "closer" but that isn't a really fast lens so your shutter speeds will be low and any shake will be multiplied. You will definietly need a monopod or a tripod to shoot the bands with that lens.

[mkh]

From page 64 in the manual.

" If you press the shutter button halfway during manual focusing, the active AF point and the foucs confirmation light in the viewfinder will light whenfocus is achieved."

[RAitch]

Cool! I didn't know that.

[willg]

From page 64 in the manual.

" If you press the shutter button halfway during manual focusing, the active AF point and the foucs confirmation light in the viewfinder will light whenfocus is achieved."
yeah i discovered that feature..its very handy

[WAL]

I actually remember reading that in the manual. It's all fine in theory to wait for the autofocus light - and with a static subject that is easy - but the average musician doesn't stand still. The shot that is the winner is the one that shows movement. There is the dilemma! I realise that the longer lense will cause me even more grief, but hey, welcome to the world of compromise. It makes it interesting, doesn't it.

When you talk about "faster" lenses what would be the recommendation? The choice of 70-200 is based upon the gear a friend uses and his results are spectacular - obviously he drinks less, as his shots are perfectly in focus!

Regards

WAL

[mkh]

By "faster" I mean a lens with a lower f number. This means that the lens opening will be bigger which will:

1. let in more light
2. allow faster shutter speeds
3. decrease depth of field
4. allow for faster autofocus

As the f-stop number goes up (number gets higher) the lens opening gets smaller so less light and longer exposeurs are required.