Is this a lens issue??
Author
Discussion

woody

Original Poster:

2,189 posts

314 months

Tuesday 15th August 2006
quotequote all
Hi guys,

After a bit of advice. Going through my GPMasters photos from the weekend and have noticed this:



Seems to be a 'halo' effect around alot of the close up shots.

Using a Canon 300D with Canon EF 75-300mm 1:4-5.6 III lens.

I know its a bit 'soft' at 300, but whats with the purple halo?? is this 'Chromatic aboration'?? and is the only way round it better quality glass??

Thanks in advance.

Chris

beano500

20,854 posts

305 months

Wednesday 16th August 2006
quotequote all
woody said:
'Chromatic aboration'??
Do you mean chromatic "abhor"-ation?

OK - apart from extracting the ****
chromatic aberration and here and here too give some theory and examples for you to compare notes

I am sure somebody will be along in a moment to help you with the cure, but your initial diagnosis looks spot on.

Woody

Original Poster:

2,189 posts

314 months

Wednesday 16th August 2006
quotequote all
Thanks for that.

Looks like I should invest in another lens..... sounds expensive though

Chris

Re the spelling - it was late, I was tired and I couldn't be ar$ed with the spell checker!!

mr noble

6,538 posts

263 months

Wednesday 16th August 2006
quotequote all
Looks similar to the recent trouble I have had with my brand new 70-200 f2,8 VR.

I take it that the shot is a 100% crop?

It does look a little soft and noisey but thats to be expected. The abberation is rather heavy though.

How old is the lens?

G

Woody

Original Poster:

2,189 posts

314 months

Wednesday 16th August 2006
quotequote all
mr noble said:
Looks similar to the recent trouble I have had with my brand new 70-200 f2,8 VR.

I take it that the shot is a 100% crop?

It does look a little soft and noisey but thats to be expected. The abberation is rather heavy though.

How old is the lens?

G


Yep 100% crop.

Have had the lens about 18 months. Noise is probably because I had it in sport mode so quite high ISO.

How did you overcome the problem?

Chris

Ed_P

701 posts

299 months

Wednesday 16th August 2006
quotequote all
I have the same lens and experienced the same problem, particularly when zoomed up to 300mm. I am a humble photography novice with a limited budget and could not justify overcoming aberration issues by investing in a top quality 300mm zoom or prime. Decided instead on a Canon 70-200 F4 L. These are available (on eBay anyway), for well under £400. Still a considerable investment, but I'm very pleased with mine.

OK, I've lost the top 100mm, so close-ups like the one you posted would not be possible. I suppose it's always a matter of balancing cost, quality and low-light versatility.

Ed ...

lotusfan

593 posts

296 months

Wednesday 16th August 2006
quotequote all
you could try not shooting at the minimum aperture, a lot of lenses (including my L series) are soft at the bottom end.
rather than use the F5.6 at 400mm, i try to get it up to F7 and it sharpens up quite a bit

LF

poah

2,142 posts

258 months

Wednesday 16th August 2006
quotequote all
the softness I think is just your technique ts not quie a pefect pan so thats why it looks a bit soft. the purple fringing is down to the lens and the subject matter. can affect some lenses more that otheres eg wide angle. stopping down helps the problem but you really only see it with contrasting colours e.g tree branches against the sky. you can remove a lot using RAW converters or CS2.