Lens before and after calibration

Ricky91t

Hello all,
Im considering calibrating my lens and have been for a while i can't seem to come to terms with not having a wide angle lens for a few weeks or maybe a month or two.:p
.Just need a quick favour from anyone who got their lens calibrated preferably a sigma and done at hahnel in cork would be nicer but id just like to see the difference it makes.
Thanks,
Richard

Roen

I never got one calibrated (can't help you there I'm afraid) but I'm wondering how come you're getting it done, is it showing any particular aberration?

Ricky91t

Lets just say its very soft at f/2.8 and the af seems to be very slighty(barely noticeable but im a nit picker ) out at close up photography
i got the lens ex display and it is mint condition so i decided id calibrate so basically its perfect,save around 150 sterling buying an ex display instead of new

Fajitas!

Which lens?

Ricky91t

its a sigma 20-40 f/2.8 ex dg and as and all that
A decent little lens and f/5.6 or above is perfect but id like a useable f/2.8

Ricky91t

f/8

f/2.8

f/5.6


These test aren't the best as they were shot while i was bored in the car
and they were below the recommended closest focusing distance

Fajitas!

Contrast & USM will sort that out - Lenses generally (Not always) are not the sharpest at their most open. I wouldn't bother sending that off to be callibrated.

Ricky91t

USM thats a sharpening method involving layers in ps?Whats its full name as i cant remember i googled it and it came back with nothing...

Fajitas!

Unsharp mask - Or you could try high pass sharpening. Even just contrast.

BanzaiBk

Hanhel's service varies between surprisingly capable and excruciatingly incompetent, I wouldn't give them the lens to calibrate when it seems like it's working as normal and take a chance on their reliability.

Ricky91t

Ok i was talking to challengemaster and he said its not that bad but the pic i shot isnt a very good example i'll get something better tomorrow and upload them full rs

Thanks all

Borderfox

Centre focus point on a tripod if you can and post a 100% crop, but to be honest most lenses will be a bit crap wide open even the Sigma EX range, dont worry about it and just take pictures.

Fajitas!

Exactly as the 'Fox says

Unless you're spending upwards of a grand (minimum), you're not going to get that sharpness straight off.

Borderfox

The shots you posted look great for the Sigma, I had one of those and that was about it at f2.8.

eas

I had that lens, mine was much worse than what your samples show. I ended up returning it.

I still have a poloraizer for it...I don't imagine I'll ever have another 82mm thread lens, if you want it PM me your address and I'll post it to you.

Ricky91t

ok shot a few this morning and they are looking sharper
I held camera firmly donw on the work top to avoid any kinda of shake

and im sorry if people think the resolution is oo high but i want people to see
This was on auto focus

And this manual..


and this just another shot on af



After seeing the difference between af and mf im begining to think that its out,
Or is it just cause im focusing very near or maybe closer than the min focusing distance

Fajitas!

The first one looks like it was in further than the min. focusing distance. Second one, the min focusing distance looks like it's halfway through the bottle, where it's sharp.

All of these were at f/2.8 yeah?

Last one is grand.

Ricky91t

yeah all at f/2.8

i see your point just noticed on the first one the the
"net wt" is quiet sharp and yeah thesecond is lightly off


Cheers for the help

Fajitas!

The thing that says it's sharp for me is I can see the pixels on the can in the last, aswell as the scratches running vertically on it.

I assume these are all at the longer end of the lens?

Ricky91t

Fajitas! wrote: »

The thing that says it's sharp for me is I can see the pixels on the can in the last, aswell as the scratches running vertically on it.

I assume these are all at the longer end of the lens?

Yeah they were at the longer end wanted to get in close so you could see more detail ill try a few aat the wide end now

Fajitas!

Yeah, try the wider end too. If you could shoot at f/2.8 , f/4 and f/9 just to compare too.

Ricky91t

They were all shot at 20mm f/2.8 al auto focus

These were shot as iso 800 which can be abit nosiy on the 20D

Uploading f/2.8/f4 and f/9 now

Ricky91t

f/2.8

f/4

f/9

Fajitas!

They really do look fine to me, now obviously, I'm not looking at it at 100%, but I don't think it's nessicary.

Leave the bottle where it is, and bring the camera back so you're getting about the same amount of the scene in the viewfinder, and shoot at those apertures again.

Calina

They look okay to me as well.

Borderfox

Looks grand