What lens thread, PART II: Judgment Day
What lens thread, PART II: Judgment Day
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tertius

Original Poster:

6,914 posts

260 months

Thursday 23rd February 2006
quotequote all

So a while I posted a what lens thread for a short zoom lens, and in the end plumped for the Sigma 18-50 F2.8 to go with my 350D.

I got the lens a day or two ago, so here are a few (varied) pics taken the next day (sorry there is a cat and a child!):

All processed RAW, but really I've no clue what to do with a RAW image so apart form converting and cropping no actual processing has been done.

All (constructive or otherwise) criticism welcome.





_dobbo_

14,619 posts

278 months

Thursday 23rd February 2006
quotequote all
Compostionally I like these, but the bottom two look slightly out of focus. Where were you focusing in each? Simpo got a dud Sigma the other week which focused a few mm out, might be worth running a couple of tests to make sure you haven't got the same?

robdickinson

31,343 posts

284 months

Thursday 23rd February 2006
quotequote all
Cat photo - obligatory with new lens.

IMO last 2 are either OOF, handshake due to long shutter speeds and/or poor dof through wide appature.

tertius

Original Poster:

6,914 posts

260 months

Thursday 23rd February 2006
quotequote all
Thanks, I'll run some test shots.

TBH I've only had the 350D a few weeks so I don't really know the camera that well, let alone the lens ...

I was letting the camera pick the focus point.

Looking at the raw images the focus point on Hamish was slap bang in the middle of his forehead, and for the cat it was where the left hand (as you look at it) ear joined th ecats head and where the LH (again as you look) join the cat.

ANd to add: the cat was 1/60 at F2.8; Hamish was 1/60 at F4.0 so could definitely be some shake at that speed, and DoF obviously pretty shallow.

>> Edited by tertius on Thursday 23 February 22:43

robdickinson

31,343 posts

284 months

Thursday 23rd February 2006
quotequote all
Switch the camera to use the center focus point only, dont let it pick.

You can half press and hold if you want focus not to be in the center, you can also exposure lock for 15 seconds with the * button too I think.

tertius

Original Poster:

6,914 posts

260 months

Thursday 23rd February 2006
quotequote all
Thanks, another shot from the same evening:

simpo two

92,896 posts

295 months

Thursday 23rd February 2006
quotequote all
Aha, now you've solved it :-)

You did process the RAW images; you made them into JPGs, but without any twiddling.

tertius

Original Poster:

6,914 posts

260 months

Thursday 23rd February 2006
quotequote all
simpo two said:
Aha, now you've solved it :-)

You did process the RAW images; you made them into JPGs, but without any twiddling.


I had this vague idea that "twiddling" might be key ...

tertius

Original Poster:

6,914 posts

260 months

Friday 24th February 2006
quotequote all
OK, focus test shots (not sure how effective these are):

First one, single focus point on "Zeebrugge":



Second, single focus point on "McCarthy" AND "RD'S EGG"

RobDickinson

31,343 posts

284 months

tertius

Original Poster:

6,914 posts

260 months

Friday 24th February 2006
quotequote all
RobDickinson said:
www.canon-dslr.com/Canon_Jan05/Canon_SLR_Focus_Test.htm


Thanks! I'll give it a shot.