Need help from the pro's!!

[madplower4]

Canon 300D, 50mm f1.8 I took these shots last night. I had great lighting, set the apperature to 1.8, let the camera choose the speed, which was about 1/2000 to 1/4000, and set the iso to 100. I used single center focal point. Came home expecting to see the crisp clear tight shallow DOF that you guys/gals get and THIS is what I get!!:evil:
What am I doing wrong, other than trying to impersonate a photographer!!
They are cropped but no other photoshop editing has been done. Please advise!!

[JusSmith]

Try sports mode so that the 300D is in AI Servo mode always. f1.8 will give you a very narrow DOF, I would stop down 2 or 3 stops, increase the iso if you need to keep the shutter speed quick. The nifty fifty isn't at its sharpest wide open anyway and isn't the fastest focusing lens either, so you will need to compromise to take those sort of shots

[madplower4]

So the AI Servo only works in sports mode for the 300D? And I thought by using an F or 1.8 it would create the shallowest dof (blurriest background) to draw focus strictly to the skater? Doesn't the smaller aperature size create a greater dof? I'll do whatever you say, I just thought that dof decreased the larger the hole. And with the high shutter speed because of all the light, I don't understand why the shot isn't tighter and crisp. Maybe the answer belongs in the form of a credit card:cry:. I already had to lie to her about the cost of the camera!!

Thanks for you advice though, it just seems that the more I learn, the more confused I become!!

[tuggnet]

...

Thanks for you advice though, it just seems that the more I learn, the more confused I become!!

I feel that way a lot! DOF is effected by several components (aperture size, distance from subject...) but I'm not qualified to address the subject.

There are many members that understand this backward and forward and they have helped me in the past.

In general, however, I thought a larger aperture combined with a fast shutter speed resulted in a shallow DOF.

True??

-et

[JusSmith]

So the AI Servo only works in sports mode for the 300D? And I thought by using an F or 1.8 it would create the shallowest dof (blurriest background) to draw focus strictly to the skater? Doesn't the smaller aperature size create a greater dof? I'll do whatever you say, I just thought that dof decreased the larger the hole. And with the high shutter speed because of all the light, I don't understand why the shot isn't tighter and crisp. Maybe the answer belongs in the form of a credit card:cry:. I already had to lie to her about the cost of the camera!!

Thanks for you advice though, it just seems that the more I learn, the more confused I become!!
AI Servo is always on in Sports mode, in other modes it automatically switches to AI Servo if it detects movement, but I don't think you can rely on it!

You are perfectly correct in what you say, what I found out when I had a 300D is that I slightly delayed pressing the shutter button all the way after achieving focus half way. When your DOF is shallow in this circumstance and the subject is moving and the camera doesn't have time to jump into AI Servo then the subject is OOF.

You can use the firmware hacks to gain control over the focus modes, I upgraded to a 20D (for other reasons as well).

See here (http://www.dofmaster.com/dofjs.html) for a DOF calculator

[Maureen Souza]

I find my 50mm/1.4 works best at 3.2 and up.

[ed2day]

Sure doesn't look like it was shot at 1.8. How far were you from the subject? Since you cropped it's hard to tell. I'm assuming you're wanting background blur when you say shallow DOF? The closer you are to the subject and the farther the subject is from the background the more the background will be out of focus.

[kawter2]

IMO 1.8 or even 2.2 is too shallow.. go to ISO400 and use TV of about 500

also get lower to the ground, shoot camera vertical (50mm isn't wide enough to shoot skating landscape)

p.s. sometimes it is easier to MF and anticipate the shot, relying on DOF

[fortinaa]

I would have to say that you were at a good distance away for the background to be that "sharp" at F1.8. To get better separation of the subject from the background, you need to be close, use a low F number, and have the subject be far from the background. Now, you are using your lens at its limits (F1.8) for these shots, which won't result in the sharpest of pictures anyway. If you get close enough, you should be able to shoot between F2.2 and 2.8 for better results. You shouldn't need any more than 1/500th second to stop any skating action.

[kawter2]

p.s. I noticed that I responded to you as to "a better way to shoot skating" vs how to get less DOF

Recipe for Less DOF

Closer to the subject,
Wider F-stops
Longer zooms (because you are basically getting the focal point that much closer to the subject.. and increasing the ratio of FG to BG)

[madplower4]

thanks to all for the advice. The learning process continues!!!!