Can polariser ruin shots?

reprazent wrote in post #12547997
The shutter speed of 1/500 should be fast enough for the rowing, BUT using one shot AF won't cut it for moving objects: as soon as you achieved focus and pressed the shutter the boat would have moved away already. The only way to AF is using AI Servo. Do you use the backbutton to AF?

Agreed. Using AI Servo on moving objects is going to get you a lot more keepers. You would have to have a wide DOF and a very fast SS to get a high keeper rate with One Shot mode. Even then, the keeper rate would be higher using AI Servo.

Also, can you post of bigger samples, because I cannot tell what I wrong from those tiny images.

reprazent wrote in post #12547997
The shutter speed of 1/500 should be fast enough for the rowing, BUT using one shot AF won't cut it for moving objects: as soon as you achieved focus and pressed the shutter the boat would have moved away already.

TGrundvig wrote in post #12548036
Agreed. Using AI Servo on moving objects is going to get you a lot more keepers.

I don't think that there is any way that a row boat at that distance, going in that direction, is going to pass out of the DoF of that lens in the time it takes to go from AF acquisition to shutter release. The effect may be there, but it would be subtle, not the gross problem that the OP is complaining of.

xarqi wrote in post #12548756
I don't think that there is any way that a row boat at that distance, going in that direction, is going to pass out of the DoF of that lens in the time it takes to go from AF acquisition to shutter release. The effect may be there, but it would be subtle, not the gross problem that the OP is complaining of.

There is always a way to mess up the focus on a moving subject. LOL

Maybe the OP was panning at a speed different than the subject was moving. I still think that AI Servo will give you better results on moving subjects.

TGrundvig wrote in post #12547712
Second thing to worry about is your angle. If you were using a CPL, circular polarizer, they work best when they are 90 degrees from the sun. If you are too close to the sun, or too far, then the affect of the CPL is not ideal and that can cause adverse results in your photos.

The above statements are quite simply wrong.


There are three ways that a polarizer can cause blurry images:

- a linear polarizer will prevent the standard AF systems in cameras from working correctly. Manual focus will still work, as will the contrast-detection AF used during LiveView.

- the darker image can result in a shutter speed that is too slow

- the filter could simply be of low quality and making everything blurry.

TGrundvig wrote in post #12548880
There is always a way to mess up the focus on a moving subject. LOL

Maybe the OP was panning at a speed different than the subject was moving.

We'll know more when we see some decent examples.

krb wrote in post #12548921
The above statements are quite simply wrong.


There are three ways that a polarizer can cause blurry images:

- a linear polarizer will prevent the standard AF systems in cameras from working correctly. Manual focus will still work, as will the contrast-detection AF used during LiveView.

- the darker image can result in a shutter speed that is too slow

- the filter could simply be of low quality and making everything blurry.

What do you mean wrong? Everyone knows that a CPL performs best when it is 90 degrees from the sun. Any variation too far in one direction or the other will have adverse affects on the image. I said nothing about adverse affects on focus, now did I?

Furthermore, the OP was shooting with a CPL, not a Linear Polarizer. The OP was also shooting in Tv mode, which would have prevented his shutter speed from changing.

TGrundvig wrote in post #12548948
What do you mean wrong? Everyone knows that a CPL performs best when it is 90 degrees from the sun.

Apparently 'everyone' thinks that the only purpose of a CPL is to darken the sky on a sunny day.

krb wrote in post #12549004
Apparently 'everyone' thinks that the only purpose of a CPL is to darken the sky on a sunny day.

Just because there are more uses than darkening the ski, it does not change the way it works. It works 'best' when it is 90 degrees from the sun when out doors on a sunny day. We are not talking about trying to remove reflections from hardwood flooring on interior shots, we are not talking about trying to remove reflections from water at all. We are talking simply about the use of a CPL and a CPL performs best when it is 90 degrees from the sun. That is not wrong, now is it?

Here the review of a CPL from the-digital-picture.com. Notice the second paragraph and the comment on 90 degrees from the sun.

http://www.the-digital-picture.com …arizer-Filter-Review.aspx

TGrundvig wrote in post #12549059
...we are not talking about trying to remove reflections from water at all.

Actually, I suspect that in the current context, that is exactly what the CPL was being used for.

Not when it is being used to darken the sky, but I'm not seeing a lot of sky in the examples posted.

TGrundvig wrote in post #12549059
Just because there are more uses than darkening the ski, it does not change the way it works. It works 'best' when it is 90 degrees from the sun when out doors on a sunny day. We are not talking about trying to remove reflections from hardwood flooring on interior shots, we are not talking about trying to remove reflections from water at all. We are talking simply about the use of a CPL and a CPL performs best when it is 90 degrees from the sun. That is not wrong, now is it?

The CPL works best at making "Blue skies become VERY blue", to quote the digital picture review, when it is 90 degrees to the sun. For other effects of a CPL the angle is far, far less important and there is certainly no "adverse" effect if it used at different angle as you originally claimed.

1. Looks to me like you weren't using a tripod. If so, this is a big part of the problem. If you were using one . . .

2. The pan head on the tripod might not be silky, silky smooth. If it is and expensive, silky smooth head, remember . . .

3. A d__n polarizer will cost you up to two full stops in shutter speed or aperture size!!! Since you had the shutter speed @ 1/500, you ended up with a shallower depth of field than if you weren't using the d__n polarizer.

I can assure you that all photographers probably start off with cheap d___n polarizer filters, and WE got:

a. Some nice photos with rich, saturated blues and less reflections . . .

b. Got some shots with abnormally weird colors of blue

c. Got some blurry shots and extreme loss of contrast within the image, thanks to the f/stop-killing little booger.

From personal experience I can truly relate on MANY occasions. Hope this helps . . .

Thanks all for your input, sorry my computer wouldn't allow me attach bigger files.

.....wow....this thread is going all over the place with information that is of wildly varying value.
Like....what is a "d___n" polarizer ? I've been around a long time, and never heard of that !

To the OP, what I would suggest you do is do some homework on the function and use of polarizing filters. This would be a good place to start, and there are many other informative sites as well:

http://www.luminous-landscape.com/tutorial​s/polarizers.shtml