HOW DO I SHOOT WIDE OPEN ON 50MM 1.8 ?!

jimmyneyugn wrote in post #10234426
this is a very informative thread.. i've learned a lot! i have shot (still) cars before with a 50 1.8 and didn't really have that much problem.. then again.. i think it's cuz i had the shutter open for a while.


ISO: 100
Exposure: 8.0 sec
Aperture: 14.0
Focal Length: 50mm


ISO: 100
Exposure: 13.0 sec
Aperture: 14.0
Focal Length: 50mm

Neither of these are shot at 1.8.

There are several valid points here, and one that hasn't been made, but to bring down to a simple plan of action...

1. Check your focus point, and set it centre, and mode to one-shot, if they're not already. If you are full-auto focus mode it will always choose the closest or moving object.

2. Test your lens at f/1.8. Stand off at about 45-degree angle from a brick wall or similar flat surface with definite detail. Using that centre point (little red-light dot in viewfinder), focus on a point that you will remember -- the corner of a certain window, or the spot just next to a certain feature of the flat surface. Do this in bright enough light that camera-shake is not an issue (shutter sped of 1/200th or faster would be good).

Look at the picture -- the target should be in perfect focus. Focus should decrease rather quickly closer than the target and more gradually past it. For example if you use a brick wall and the target is clear, you might get about two bricks in front of it and four behind it before a certain level of blur is reached. If you don't get this pattern, the lens is mis-focusing. Try more than one shot from a few angles on a few subjects to be sure.

3. As the other posters said, use a much smaller aperture for a car show. On a bright day, I will rarely switch away from f/16 at a car show except for specific desired effects.

You can also use a MF together with the 5X magnified LiveView. It's nowhere near as quick or convenient as is shooting through the viewfinder but it produces much higher percentage of keepers. Nifty fifty is also quite soft at 1.8, specially at the borders so you could be better off composing your subject centrally and later cropping for a better composition
My lens, even with only the central AF point usually focuses close but not quite spot on the subject. Another often mentioned trick is to AF multiple times on the same spot before taking the shot, though I must confess I didn't see much difference. It's always a good idea to focus on a high-contrast spot on your subject.

MLphoto wrote in post #10234213
so basically this isn't exactly the best lens for what I'm shooting mounted on a 1.6 crop body?
maybe something like a 35mm would be better.

MLphoto wrote in post #10234314
I guess I'll shoot at a lower aperature next time, thats all I needed to know thanks

Your choice of lens has absoutely nothing to do with your problem.

It is possible that the lens is broken, but we cannot tell that.

It appears that either you are moving the camera rather wildly or you have not set up your camera properly to autofocus with the lens attached or both.

The lens could have been switched to manual focus as several folks have suggested.

In addition to ensuring that the switch on the lens is set to AF and not to MF (Manual Focus), you should be using the One Shot AF mode for images like the ones you showed us.

Try a test shot using the 50 f/1.8 and then another using another lens in place of the 50 f/1.8 lens with both lenses set to AF. If the camera focuses one lens properly and not the other, then the lens may have a problem that requires repair.

The problem is NOT simply your choice of f/1.8 for the aperture setting. At least one plane in the image should have been in focus, but nothing appeared to be in focus in the shots I looked at. I suspect operator error of some sort.

User error. You posted pics in focus at f11 lol.

Imagine taking a landscape pic at f1.4 and see how much is in focus.

Down_Shift wrote in post #10236106
User error. You posted pics in focus at f11 lol.

Imagine taking a landscape pic at f1.4 and see how much is in focus.

Speaking of user errors, you do know that the pics that were in focus are not posted by the same person as the out of focus pics, right?

Are you sure you were on autofocus? Looks to me like you need to use your camera a little more instead of just buying another lens

EmmaRose wrote in post #10236399
Are you sure you were on autofocus? Looks to me like you need to use your camera a little more instead of just buying another lens

According to DPP, all 3 had active AF points, and 2 of the 3 had more than one active AF point.

MLphoto wrote in post #10234314
I guess I'll shoot at a lower aperature next time, thats all I needed to know thanks

The photos you've posted out of focus, so just stopping the lens down won't really solve your problem. You need to either change your focus mode, change your focusing technique, or have your gear looked at.

This is a photo of a car taken at f/1.8 with a 50L. While the rear of the car is falling out of focus, the front of the car is clearly in focus:

I'd say at f1.8 the Dof is very shallow and exact focusing is a must. If the subject is moving put the cam in AI Servo move it may help. Otherwise shut down to f5.6.

Paul

P4ulG wrote in post #10236591
I'd say at f1.8 the Dof is very shallow and exact focusing is a must. If the subject is moving put the cam in AI Servo move it may help. Otherwise shut down to f5.6.

Paul

Using a 50mm @ 1.8 the DOF is 8 inches when 10 feet away and about 3 feet if you step back to 20 feet away. Not a large DOF but it is enough that some part of the car should be sharp, as shown in Tim's shot above.

It's obvious that the OP missed focus entirely in every shot. No part of any of those sample images is in focus, so I'd guess against focus point issues. Either the lens (or lens/body combo) has a severe problem, the AF/MF switch is set to manual focus, or the OP has terrible technique. Just to repeat the above posts: This has nothing to do with DOF, and nothing to do with shooting wide open. OP simply missed focus completely.

to all the manual focus suggestions...the exif says the shots were in AI Focus...

What possible setup error would allow the image to be recorded without focus being met when in auto?