# Holy ****atauke Mushrooms! Some Questions About my Temporary Toy



## PhilGarber (Jun 29, 2009)

EDIT-Posted some photos taken with the lens. I know, the noise levels are terrifying.

Hi-

Behold, my lovely rental! This baby from Lensprotogo is a 70-200mm 2.8 IS 'L' Lens. After putting my camera around my neck, I can see where all the bad jokes come from.

Here are my few questions, please keep in mind this is my first IS or 'L' lens.

1: What's the difference from IS mode 1 and 2?

2: What's does it mean to focus at infinity? I've heard this term before. \

3: What does the switch that says 1.4m-Infinity and 2.5m-infinity mean?

4: Why does the focus ring work normally even  with AF on?


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## SrBiscuit (Jun 29, 2009)

i dont have any experience with canon, but i can answer #4.

it makes it much more convenient to make fine adjustments without having to switch to manual mode. i have it on my 18-70, and i like it...i dont use it often, but it;s nice to know it;s there.

thats a sweet lens.
have fun!


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## Dylan-Fishman (Jun 29, 2009)

Zebra camera! can't answer any of those questions.... sorry. Sweet lens though


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## PhilGarber (Jun 29, 2009)

Thanks Biscuit!


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## PhilGarber (Jun 29, 2009)

Thanks Dylan. Just wishin' it were mine.


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## kundalini (Jun 29, 2009)

PhilGarber said:


> 3: What does the switch that says 1.4m-Infinity and 2.5m-infinity mean?


 This should reduce the AF hunt if your subject is typically between 1.4M to infinity or 2.5M to infinity.


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## PhilGarber (Jun 29, 2009)

kundalini said:


> PhilGarber said:
> 
> 
> > 3: What does the switch that says 1.4m-Infinity and 2.5m-infinity mean?
> ...



You've lost me.. It takes less time to auto focus on those setting when the lens is a certain distance away?


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## musicaleCA (Jun 29, 2009)

Basically. A quick low-down on how auto-focus works might help.

Quoted from here.

The process of autofocusing generally works as follows:
              (1) An autofocus processor (AFP) makes a small change in the focusing distance.
              (2) The AFP reads the AF sensor to assess whether and by how much focus has improved.
            (3) Using the information from (2), the AFP sets the lens to a new focusing distance.
            (4) The AFP may iteratively repeat steps 2-3 until satisfactory focus has been achieved.

"Focus hunting" is when the AFP gets stuck in the iterative process of steps 2-3. This happens when focusing on a very low-contrast object (say a blank white wall, or a matte black surface), and happens more often in really low light.

Focusing at infinity is when the lens if focused at its hyperfocal distance. It is the distance at which all objects beyond that point can be brought into acceptable focus. For instance, if you are shooting a landscape, you would focus at infinity, and that should bring everything beyond the lens' hyperfocal distance into focus; the aperture controls the DoF behind (toward the camera) the hyperfocal plane in this case.

As for focus working all the time, you forgot that it's also a USM lens. That stands for "ultra-sonic motor". The design allows for you to manually focus all the time, so if AF messes-up, you can fix it quickly. It's also hella fast compared to previous focusing mechanisms. Also, the focus ring on the outside of the lens doesn't move while auto-focusing.

As for different IS modes, I'm clueless because I've never owned a lens with more than one IS mode, but my guess is that one mode may give more stops of IS at a cost; perhaps it eats more power or degrades IQ a bit...or...something. I say read the manual for that one.

Oh, and as for the term "L", it just means something along the lines of "luxury" or "ludicrously expensive". :greenpbl: It's Canon's way of saying that the lens is their cream of the crop; that great care and attention was put into its design and manufacture to give it the best IQ possible. They also come with lens hoods included, unlike other Canon lenses where the hood must be bought separately (in the case of the uber-long lenses, like the 300mm and 400mm lenses, the hood is actually made by hand, because it's not cost-effective to create them en-masse, as they sell so few of the lenses; that makes the hoods absurdly expensive to replace).


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## PhilGarber (Jun 29, 2009)

musicaleCA said:


> Basically. A quick low-down on how auto-focus works might help.
> 
> Quoted from here.
> 
> ...



So.. focusing at infinity is fancy DoF? I feel stupid.


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## PhilGarber (Jun 29, 2009)

Thanks for the time spent on the reply, by the way!


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## Soocom1 (Jun 30, 2009)

OK I have the 70-200 F4. ( About a full pound lighter and it does not have the IS on it), BUT here is what the Canon dealer instructed me on when I purchased the lens a short time ago. 

IS Mode 1 is for Vertical and Horizontal shake. 
Mode 2 is vertical only.  

I.e. 1 is good for hand held, 2 is good for tripod-monopod mounted lenses. 

The 1.4 and 2.5 is actually designed for the focus distance. 

1.4 m is for focusing on anything closer than 1.4 meters all the way to infinity.
The 2.5 m is for focusing in on subjects greater than 2.5 meters all the way to infinity. 

Yes the focus ring WILL work in AF mode, but not advised. It can damage the teeth inside the mechanism. It is best to just switch to MF if that is what you intend to do. 


P.S. It is best to keep the lens mounted on a tripod/monopod because of the weight. 

P.P.S. Watch the weight of the lens, this thing CAN and WILL damage the mounting lugs on the camera if you DO NOT either mount the lens on a tripod, or carry the camera/lens w/o 
supporting the lens someway.


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## JamieR (Jun 30, 2009)

I was considering renting one myself. 

How much did it cost you and how long do you have it for?


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## PhilGarber (Jun 30, 2009)

Thanks Soocom! That was really helpful. Esp. About the IS modes!


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## PhilGarber (Jun 30, 2009)

Jamie-

The lens cost $150.00 USD for 2 weeks from lensprotogo. That cost covered shipping both ways and insurance.


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## JamieR (Jun 30, 2009)

Thats really cheap, the cheapest i can find here in the UK is about £140, which works out at about $230.


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## PhilGarber (Jun 30, 2009)

I don't think I read on the website that rentals were restricted to the US.


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## HeY iTs ScOTtY (Jun 30, 2009)

whats it like having a hubble telescope one your dslr? lol


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## PhilGarber (Jun 30, 2009)

It sure feels like the Hubble when it's on my neck.


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## musicaleCA (Jun 30, 2009)

Soocom1 said:


> Yes the focus ring WILL work in AF mode, but not advised. It can damage the teeth inside the mechanism. It is best to just switch to MF if that is what you intend to do.



He's talking about a USM focus mechanism. They were designed with full-time MF in mind.


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## PhilGarber (Jun 30, 2009)

Thanks CA. I was wondering why the comments seemed contradicting.


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## musicaleCA (Jun 30, 2009)

No problem. I believe he meant the older versions, but USM systems are designed to have continuous MF.


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## Soocom1 (Jul 9, 2009)

Well Again, I have the 70-200 f4. 
I have used the focus ring in AF, and found alot of resistance in it. Personally, I wouldnt reccemed useing it is AF mode. Just haveing personal experiance with things of this kind (and being an auto mechanic and gun nut) I have learned not to force things that dont like to move freely.


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## bigtwinky (Jul 9, 2009)

So are you going to post some pics taken with the lens or what??


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## Big (Jul 10, 2009)

How much does it cost to rent one of those? Like per day for instance?


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## FrankLamont (Jul 10, 2009)

I'll answer anyway...

1) The IS modes depend on whether you want to be able to pan... IS 1 covers everything (vertically + horizontally), IS 2 only vertically
2) Infinity focus. It's pretty straight forward.  Focus at infinity... focusing from whatever distance to infinity.
3) 1.4m-infinity means that the lens will seek focus for the full focus range of the lens (1.4m is minimum focusing distance for the 70-200mm) and 2.5m-infinity just means it only searches past 2.5m
4) Unless the lens is an AF/MF and then -> MF lens, you shouldn't turn the focus ring without setting it to MF first. If the lens has the AF/MF option, you can autofocus and manual focus at the same time (not stopping it while it's autofocus is running, of course, ie, the ring is turning)


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## PhilGarber (Jul 13, 2009)

bigtwinky said:


> So are you going to post some pics taken with the lens or what??



Good point, I should. Ok, one sec.


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