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Occasional Contributor
Posts: 6
Registered: ‎03-31-2017

Re: Eos rebel xti

Ok I actually followed all of that. So should I remove the filter when glare is not an issue or in low light situations or is it supposed to be a permanent fixture on the lens?
Occasional Contributor
Posts: 6
Registered: ‎03-31-2017

Re: Eos rebel xti

The 75-300 mm lens I have has a switch on it for AF or MF. Would the bower manual lens be much different than operating my lens on MF?
Esteemed Contributor
Posts: 4,560
Registered: ‎08-13-2015

Re: Eos rebel xti


Elev8or12 wrote:
Ok I actually followed all of that. So should I remove the filter when glare is not an issue or in low light situations or is it supposed to be a permanent fixture on the lens?

Thanks, that's good to know that you followed it.  Be sure to try the experiment with the TV screen.  Solid state light sources emit highly polarized light.  An LED television probably emits light that is polarized vertically.  Your CP filter reduces how much of it can pass through, until the filter is oriented perpendicular to th light coming from the LED television.

 

Generally, I would say that the CP filter would not be needed in many shooting scenarios.  Many people like to use a clear filter, sometimes called a protecto filter, on their lenses to protect the front element from harm.  I use clear, protecto filters on all of my lenses.

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"I don't rent software. I use Photoshop CS6, ACR 9.8 and Lightroom 6.8 ."
Esteemed Contributor
Posts: 4,560
Registered: ‎08-13-2015

Re: Eos rebel xti

[ Edited ]

Elev8or12 wrote:
The 75-300 mm lens I have has a switch on it for AF or MF. Would the bower manual lens be much different than operating my lens on MF?

Your autofocus lenses would cause the camera body to behave differently from what a fully manual lens like the Bower would. Even if your autofocus lenses are switched into MF mode, they still contain electronics that would communicate with the camera and would confirm when focus was achieved.  

 

Basically, the selected AF point would light and cause the camera to beep.  To see this in action, the camera's metering system needs to "alive" and active.  In other words, the display in the viewfinder needs to be lit up.  Normally, you would wake up the metering system by half pressing the shutter button.  

 

With the lens in AF mode, pressing the shutter halfway should cause the camera to lock focus on something, and light up an AF point.  With the lens in MF mode, you would need to maintain holding the shutter half pressed while rotating the focus ring until a focus confirmation lock is achieved.  Fairly easy to do when you're holding the camera fairly stationary.  Not quite so easy to do when you're moving the camera rig as you attempt to track a bird in flight.

 

The Bower lens, and other fully manual lenses like it, cannot communicate with the camera body.  With the a fully manual lens, you would not get a focus confirmation beep.  With the Bower, you would have two choices.  Either relying on your ability to infer focus through the viewfinder, or you would use "Live View" mode and the LCD screen, which can magnify the image and help you to resolve sharp focus on a subject.

 

Some manual focus lenses, however, are equipped with electronics to communicate with the camera, and cause the camera to confirm focus.  This behavior in today's DSLR's serves the purpose of assisting you with focus, just like the old manual focus lenses had screens that helped you to find focus.

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"I don't rent software. I use Photoshop CS6, ACR 9.8 and Lightroom 6.8 ."
Esteemed Contributor
Posts: 3,224
Registered: ‎06-25-2014

Re: Eos rebel xti


Elev8or12 wrote:
Ok I actually followed all of that. So should I remove the filter when glare is not an issue or in low light situations or is it supposed to be a permanent fixture on the lens?

Definitely not a permanent fixture. Use it to suppress reflections off of water or to darken a blue sky. (Works best when the sunlight is coming from the side and the sun is about halfway up in the sky.) Otherwise leave it off. Anything you add to your lens has the potential to degrade the image a little.

Bob
Boston, Massachusetts USA
Honored Contributor
Posts: 7,533
Registered: ‎12-07-2012

Re: Eos rebel xti

Elev8or12,

Looks like you have a decision to make. Doesn't it?  The Bower is the least expensive way to get into a super telephoto.  You don't expect it to behave like a $1000 Canon "L" do you?  If you do, you will be disappointed.  However, it does work and despite the warnings, I know anyone can learn to use one.  It is foolish to think just because one guy can't, nobody can.  Again, don't listen to people that don't own and use the gear.

 

If you must have focus confirmation, you can buy a programmable focus confirmation chip and install it.  I don't use one because I can manually focus the lens but they are available.  They cost around #25 bucks I think.  On static subjects it is no big challenge to focus.  On moving or flying birds it is a challenge.  But it is even a challenge with a fully AF lens, also.

 

I am not pushing the Bower, to me they are just a curiosity.  Something to play with but they are a viable least expensive option.

 

As to you polarizer on the 75-300mm, I think it is mostly a never use it.  That lens doesn't have the ability to give up any IQ or aperture.  Again it is probably best used on static subjects.  Remove it.

A lot of Canon stuff. Along with, a lot of other stuff.
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