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KM 100-200mm f4.5

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gian View Drop Down
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Post Options Post Options   Quote gian Quote  Post ReplyReply Direct Link To This Post Topic: KM 100-200mm f4.5
    Posted: 31 January 2006 at 19:30
Hi!

I have bought the KM AF 100-200mm f4.5 just few weeks ago after some searches, thinking that it is a nice lens, comparable in quality to the famous KM AF 70-210mm f4.

After using it last week-end, I noticed that it is not really sharp.
I have two good lenses to compare it with:
a KM AF 28-75mm f2.8 (D) and a standard prime KM AF 50mm f1.7

Today I decided to take some pictures to test its sharpness along all the apertures (f4.5-f22) and to find its "sweet spot".


This is the workflow:

- tripod
- remote cable
- AS off
- Manual Focus
- focal lenght 200mm
- ISO 200
- natural light (direct sun, outside)
- subject: flower
- subject distance 2,5 meters for the 100-200mm
- Only RAW
- 1 pic for each f stop
- 5-10 sec pause after each f stop setting, to avoid tripod vibrations

Then I switched the lens to the 50mm and I recomposed the picture trying to get the same size of the flower.


Post processing:

- Adobe Camera RAW.
- All the parameters set to 0 except for "curve" set to "medium contrast".
- 100% crop @ 400x267
- No resize
- No USM
- save to jpg, medium-high quality (8)


Here are the results.

I tested it only at 200mm because I usually use it like a prime lens.. :)

I would like you to comment this test with suggestion to achieve more significative results.

Would you add or modify something in the workflow?
Are the pictures indicative of something?
Is it comparable to the KM 70-210 f4?
Where is the sweet spot?
What are your conclusions?


Note: I have a cr@ppy tripod, and I did a mistake using it extended at its maximum.
But I had no choice because of the enviroment.
::: Gianluca ::: Gallery ::: Life is once, forever - Henri Cartier-Bresson
 



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nozzle View Drop Down
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Post Options Post Options   Quote nozzle Quote  Post ReplyReply Direct Link To This Post Posted: 31 January 2006 at 21:09
funny thing

it seems the sweet spot is about f 5.6 after that itīs getting quite mushy.

is it comparable too 70-210?

i donīt know, but shoot a Southern Comfort bottle (it has a very usable label ;-)) and then we could compare. from neighbour to neighbour so to speak %-)

markus
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gian View Drop Down
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Post Options Post Options   Quote gian Quote  Post ReplyReply Direct Link To This Post Posted: 31 January 2006 at 21:27
Thanks Markus :)

One thing that I have missed is to check the focus point, maybe that it is different (but the crop area is the same.... )
And this is a mistake of mine.

I had the same impression.
It sounds strange to me.

Any comments about it?
::: Gianluca ::: Gallery ::: Life is once, forever - Henri Cartier-Bresson
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eccl View Drop Down
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Post Options Post Options   Quote eccl Quote  Post ReplyReply Direct Link To This Post Posted: 01 February 2006 at 05:41
Hi Gian,
I have conducted a similar test of all my lenses a while ago. I use a 5D on a carbon fiber tripod with ball head, 2 sec mirror lockup, RC1000S and filter off, hood on but shooting indoor and shoot in JPG.

Here's some 100% center crop of the following lenses at 200mm (100-200/4.5, 100-300 APO (D), 70-210/4 and 70-210/3.5-4.5

200mm wide open (100-200/4.5, 70-210/4 and 70-210/3.5-4.5)


200mm @ F5.6 (4 lenses)


200mm @ F11 (4 lenses)


Hope the above is helpful for anyone considering any of the above 4 lenses.

eccl



Edited by eccl - 01 February 2006 at 21:44
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gian View Drop Down
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Post Options Post Options   Quote gian Quote  Post ReplyReply Direct Link To This Post Posted: 01 February 2006 at 23:27
Thank you ECCL, very very useful! :)

I think that I will spare some money to buy the 100-300.. :)

Ok, I have to buy a 20mm, a 90/100mm macro, 100-300mm.

In your test the 100-200 seems to be sharper stopped down to f11.
Next time I will use 2 sec mirror lockup and center crop.

Good work!
::: Gianluca ::: Gallery ::: Life is once, forever - Henri Cartier-Bresson
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gsaronni View Drop Down
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Post Options Post Options   Quote gsaronni Quote  Post ReplyReply Direct Link To This Post Posted: 02 February 2006 at 00:05

Very good comparison. Really the 100-300 is the winner, and is very usable because of its size and weight.

I have the 100-300 APO(D), and dont use it very much, I have it for the day you need some extra reach. I think I am not going to buy the overpriced 70-210 f4, and I will save for a good prime: 28mm f2, 35mm f2 or 85mm f1.4.

I am searching a good and inexpensive 28mm f2.8, but I am loosing some good ebay lenses of this type.

Regards
35/1.8 | 50/1.4 | 50M | 100/2
CZ 16-80 | Tamron 70-300 USD
XZ-2 | A700 | A77 M2
http://www.flickr.com/photos/gsaronni/
 



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gian View Drop Down
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Post Options Post Options   Quote gian Quote  Post ReplyReply Direct Link To This Post Posted: 02 February 2006 at 13:22
It would be interesting to see a bokeh comparison too...

(for portraiture/birding usage)

I really like the 70-200 f2.8 SSM's one, (ehhh.. :) but to remain in a cheap choice, wich one of these lenses has the nicest out of focus?

I've read that the 100-300 is not impressive in this regard, is it true?

I hope they are almost equivalent, so that the choice is siple: 100-300.

Edited by gian - 02 February 2006 at 13:41
::: Gianluca ::: Gallery ::: Life is once, forever - Henri Cartier-Bresson
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alberto View Drop Down
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Post Options Post Options   Quote alberto Quote  Post ReplyReply Direct Link To This Post Posted: 02 February 2006 at 14:21
So the 70-210/3.5-4.5 seems to be far better than 70-210/4...

That's fairly unexpected to me. As I was considering a tele-zoom for hiking and I know about a 70-210/3.5-4.5 for 90 Eur, I just have to go to lens data section to check if it is lightweight and small enough for me. Thank you very much, eccl
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eccl View Drop Down
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Post Options Post Options   Quote eccl Quote  Post ReplyReply Direct Link To This Post Posted: 02 February 2006 at 16:23
Please bear in mind the test I conducted was from what I have and sample variance does exist for any lenses. The 70-210/4 does have better sharpness at the edge than the 70-210/3.5-4.5
I'll try to post some edge comparison shots later today.

eccl

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