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VIP
Posts: 11,550
Registered: ‎08-13-2015

Re: New member needs help


@TCampbell wrote:

I seem to recall that Canon deliberately slows the AF speed when the notice the extender is being used.  A slower AF speed is fairly normal.  There were a few reasons why it was a good idea to do that... I do not recall specifically what they were.

 


I am pretty certain that you're correct.  I read about that, too, on one of Canon's web sites.  Don't quote me, but I think it was related to the reduction in incoming light, so they give the camera a brief moment of more time to gather liight.

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"Doctor told me to get out and walk, so I bought a Canon."
VIP
Posts: 13,883
Registered: ‎12-07-2012

Re: New member needs help

"...they give the camera a brief moment of more time to gather liight."

 

I really doubt that.  The camera doesn't gather (store up) light up to a certain point before it can AF.  It either has it or it doesn't.

EB
EOS 1DX and 1D Mk IV and several lenses!
VIP
Posts: 11,550
Registered: ‎08-13-2015

Re: New member needs help


@ebiggs1 wrote:

"...they give the camera a brief moment of more time to gather liight."

 

I really doubt that.  The camera doesn't gather (store up) light up to a certain point before it can AF.  It either has it or it doesn't.


Right, it either has it or doesn't it.  One of the main reasons was related to the reduction in available light, of that I am almost certain.  Maybe, the camera performes a redundant calculation, which would take more time to process.

 

As far as gathering light goes, it is not instantaneous.  At some point the engineers must define a time period to collect a light sample.  For example, the sampling period could be 1/32000 of a second under normal use, or it could be reduced to 1/16000 with the extender, which could slow down the AF performance.

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"Doctor told me to get out and walk, so I bought a Canon."
VIP
Posts: 13,883
Registered: ‎12-07-2012

Re: New member needs help

"...the sampling period could be 1/32000 of a second under normal use, or it could be reduced to 1/16000 with the extender, which could slow down the AF performance."

 

I don't doubt that. We all know a t-con slows the AF down but the camera is not 'gathering' more light to make it happen. It has what it has.

EB
EOS 1DX and 1D Mk IV and several lenses!
VIP
Posts: 11,550
Registered: ‎08-13-2015

Re: New member needs help


@ebiggs1 wrote:

"...the sampling period could be 1/32000 of a second under normal use, or it could be reduced to 1/16000 with the extender, which could slow down the AF performance."

 

I don't doubt that. We all know a t-con slows the AF down but the camera is not 'gathering' more light to make it happen. It has what it has.


Okay, Ernie.  You are correct.  Whatever you say.

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"Doctor told me to get out and walk, so I bought a Canon."
Reputable Contributor
Posts: 531
Registered: ‎01-31-2017

Re: New member needs help


@Waddizzle wrote:

You should give it more time to learn.    



There's no evidence of that ability. Hence, constant variations of "What should I buy next?"

Frequent Contributor
Posts: 80
Registered: ‎02-12-2017

Re: New member needs help

Is there a trustworthy and affordable place to rent a Canon f/2.8 70-200 IS ll lens for a tryout?

Honored Contributor
Posts: 7,912
Registered: ‎11-13-2012

Re: New member needs help

Lensrentals.com is one place.
John Hoffman
Conway, NH

1D X Mark III, Many lenses, Pixma PRO-100, MX472, LR Classic
Frequent Contributor
Posts: 80
Registered: ‎02-12-2017

Re: New member needs help

What paper and Canon printer should I buy for my pix?

Honored Contributor
Posts: 7,912
Registered: ‎11-13-2012

Re: New member needs help

Canon Pixma Pro-100. Get it on sale now for $130. Comes with some Canon paper. 

 

B&H may still have a $79 special. 

 

These prices are after rebate. 

John Hoffman
Conway, NH

1D X Mark III, Many lenses, Pixma PRO-100, MX472, LR Classic
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