August 9, 2007 at 8:49 pm
Hello people.
I have a Canon 300D and a SIGMA 28-300 zoom lens. I tend to use autofocus and only use the P setting as I dont fully understand how the camera works! I have set it to focus in the middle box in the view finder.
However, when I use 150-300mm the photos hardly ever come out really sharp. I always end up having to sharpen the final shots and sometimes they are really bad quality!
Is it the quality of the camera / lens? Is it the fact I am just too slow or not using my equipment correctly. Any advise would be welcome.
Anthony
By: PMN - 14th August 2007 at 18:07
2) Use AF, but use Tv mode setting and use a shutter speed higher than your zoom. eg 300mm use 1/400
You don’t necessarily have to shoot in Tv. Av will also work, you just need to keep an eye on the shutter speed in the bottom of your viewfinder while taking the shots!
Paul
By: aiuk - 14th August 2007 at 17:17
“To infinity and beyond …. ” :diablo:
Things I should try then…
1) Set camera to infinity and use an aperture of at least f8.0
2) Use AF, but use Tv mode setting and use a shutter speed higher than your zoom. eg 300mm use 1/400
3) Try shooting with ISO 200 to get slightly sharper images when aircraft moving fast.
Any others to add?
ps Moggy, I’m gonna go with 10, 11 and 17 from you list!!! ( I have no idea about the focal length thing!)
By: PMN - 14th August 2007 at 15:41
Good point. I hadn’t considered the zoom issue.
However you do lack creativity.
1) Buy eski and some ice blocks
2) Fill eski with bottles of Adnams Broadside
3) Go to golf range
4) Drink bottle of Broadside
5) Set up tripod
6) Drink another bottle
7) Attach camera to tripod
8) Drink another bottle
9) Take first exposure
10) Drink another bottle
11) Expose yourself
12) Have some more Dabnams BroadA*se
13) Laugh at golfers’ trousers
14) Expose another bottle
16) Use tripod to support yourself
17 Who cares about focal length anyway? 😀
Now that was funny! 😀
Paul
By: Moggy C - 14th August 2007 at 14:44
It also depends on focal length though, and working it out on a lens like my Sigma 50-500 may take some time!
Good point. I hadn’t considered the zoom issue.
However you do lack creativity.
1) Buy eski and some ice blocks
2) Fill eski with bottles of Adnams Broadside
3) Go to golf range
4) Drink bottle of Broadside
5) Set up tripod
6) Drink another bottle
7) Attach camera to tripod
8) Drink another bottle
9) Take first exposure
10) Drink another bottle
11) Expose yourself
12) Have some more Dabnams BroadA*se
13) Laugh at golfers’ trousers
14) Expose another bottle
16) Use tripod to support yourself
17 Who cares about focal length anyway? 😀
By: PMN - 14th August 2007 at 14:28
How’s about a trip to the nearest golf driving range?
Stick the camera on a tripod, focus at infinity, shoot off a shot at each aperture setting. Hey presto – instant depth of field info.
Moggy
It also depends on focal length though, and working it out on a lens like my Sigma 50-500 may take some time! Also in truth I’m not sure I can stay out of the pub for that long! 🙂
Paul
By: Moggy C - 14th August 2007 at 11:41
I’m not sure how to work out the near limit of the depth of field when focussed at infinity
How’s about a trip to the nearest golf driving range?
Stick the camera on a tripod, focus at infinity, shoot off a shot at each aperture setting. Hey presto – instant depth of field info.
Moggy
By: Snapper - 14th August 2007 at 11:10
Infinity on a lens means from ‘this point’ to infinity will be acceptably sharp. My lightyear lens, however, is different in that you can turn it to infinity and beyond.
By: PMN - 14th August 2007 at 10:38
Am I right in believing that if you set at “Infinity” it doesn’t necessarily mean that you will have ANYTHING your photographing truly in focus
That’s quite possible, but like any other technique you need to know when to and when not to use it. If you set to infinity and nothing is in focus it’s the photographer’s fault for using the wrong technique in the wrong situation. Experimenting over time will allow you to judge when a technique like this might be effective.
Exactly….and how often are aircraft actually far enough away to be at ‘infinity’?
Actually quite often in certain circumstances. As I say, I’m not sure how to work out the near limit of the depth of field when focussed at infinity, I just know I’ve tried that technique with more success for aircraft in the air than on the ground, particularly at airshows. If you do try infinity, remember the near limit will be less the higher aperture you use, so try stick to a minimum of f8 or higher if the light allows. I’d definately say it’s a technique best used for fast aircraft in the air though, as opposed to aircraft on the ground. Then again, trying different techniques in any situation is good. You can learn just as much from getting it very wrong as you can from getting it very right!
Paul
By: ALBERT ROSS - 14th August 2007 at 09:19
No.
Moggy, infinity should be used as a far value when working with hyperfocal distance.
Exactly….and how often are aircraft actually far enough away to be at ‘infinity’?
By: RobAnt - 14th August 2007 at 02:03
Am I right in believing that if you set at “Infinity” it doesn’t necessarily mean that you will have ANYTHING your photographing truly in focus – because focusing on infinity means focusing at some hypothetical far off distance, much further than the eye can see…? And anything that is in focus is just a by product of depth-of-field, …… or a figment of your imagination!! 😀
Just curious
By: LesB - 13th August 2007 at 23:14
Back to the original query . . .
All very fine and good but my guess is that using a tele with the 300D he is experiencing a bit of camera shake due to the P setting giving him slowish shutter speeds.
😀
By: Moggy C - 13th August 2007 at 22:53
Ah, big gorilla / Empire State building?
What are those biplanes?
Moggy
By: Snapper - 13th August 2007 at 21:16
Not a chance tonight – google it, I’m listening to King Kurt.
By: Moggy C - 13th August 2007 at 21:12
Moggy, infinity should be used as a far value when working with hyperfocal distance.
Can you do that for me again in English please Snaps?
Moggy
By: Moggy C - 13th August 2007 at 21:10
Again, Moggy, my apologies for the confusion.
Not a problem.
People sometimes confuse me with my alter-ego 😉
Moggy
By: PMN - 13th August 2007 at 20:59
Hi guys!
Well, I wasn’t expecting this kind of response!! lol
Being a bit of a novice, I am learning as I go along. My question is (all be it very simple)… How do I select the focus to infinity? !!
Would setting a higher shutter speed eg 1/800 at 300mm produce a sharper pic??
Thanks!!
🙂
To set the focus to infinity, on the focus ring of the lens there should be a symbol at one of the extreme ends like two oo’s joined together, leading to a line. Just line it up with the marker and you’re set to infinity.

As for the high shutter speeds, it won’t make the lens sharper as such, but it will reduce your chances of shots being ruined by motion blur! 🙂
Paul
By: Snapper - 13th August 2007 at 20:18
No.
Moggy, infinity should be used as a far value when working with hyperfocal distance.
By: aiuk - 13th August 2007 at 20:09
Hi guys!
Well, I wasn’t expecting this kind of response!! lol
Being a bit of a novice, I am learning as I go along. My question is (all be it very simple)… How do I select the focus to infinity? !!
Would setting a higher shutter speed eg 1/800 at 300mm produce a sharper pic??
Thanks!!
🙂
By: PMN - 13th August 2007 at 17:46
There was / is no intention to patronise. I really am struggling to get my head around this.
In that case, please accept my apologies. I mis-interpreted your post.
Switching to manual focus and leaving the lens at infinity for aircraft in the air certainly can work well and I occasionally do just that at airshows, and as you say cuts down on focussing time. I’ve just never had much success with that technique for aircraft on the ground, but it may well be worth Anthony giving a try. We all have our own little methods!
I still maintain gaining a little more technical knowledge on the camera itself would be the best way of improving, though. Getting my head around shooting modes and which is the best to use for certain situations took me what felt like an eternity to learn, but the more information you take in and the more practice you get, the more switching between Av and Tv and making other adjustments becomes second nature.
Again, Moggy, my apologies for the confusion.
Paul
By: Moggy C - 13th August 2007 at 16:42
There was / is no intention to patronise. I really am struggling to get my head around this.
but why would you want to do that anyway?
In my simplistic way it seemed an ideal solution to the posters original question. If for some reason his auto-focus wasn’t coping then locking it on infinity would relieve him of that worry. (And presumably save focusing time?)
Moggy