Help Haze in shots from Sigma lens

[bernards]

I just bought a Sigma 70-300 APO Macro Super II lense to mount on my D70. I did a few test shots and found that most of the shots have a slight haze. Very light but visible when compared to my kit lens. Funny thing is sometimes it can get pretty bad when shot at 300mm. It's a nice cloudy but bright day today. Thru the viewfinder, everything is crisp and clear. But after downloading to the comp, the haze appears.

Is this a due to lense defect or caused by some technical/atmospheric condtion? Should I send in the lense for repair?

This shot was taken at 220mm. You won't see the hazy cast by itself. But when sequenced next to a pic from the kit lense. There is a very slight cast.

At 270mm. You can see a hazy whitish cast to the shot.

This one at 300 mm focused at a nearer object. You can see the haze very clearly. Whole pic looks washed out.

 

[ndroo]

are u referring to the blueish tint? i noticed that when i was using this lens, but with auto WB set to -2, seems okay. i may be wrong though.

 

[bernards]

It's not a exactly a colour tint, but the hazy does look at bit colder on the bluish side. If you look at the bottom two pics. They actually look washed out and have a hazy look in them. Kind of like projectors getting washed out when used in a bright room.

BTW. My WB is set to A. Same settings on my kit lense seems to be perfectly all right at all focal lengths. On this Sigma 70-300 has got this problem at the longer focal lengths. Not sure if this is a fundamental problem with long focal lengths, or I have a defective lense.

 

[reflecx]

Just seems to be a case of lack of contrast. Are you shooting at the widest aperture? Try stopping down to a smaller aperture and upping the ISO if necessary. Many lenses will have reduced contrast and sharpness at max aperture.

 

[bernards]

Hi reflecx,

I was shooting at f13. Is this sufficient, or should I use a even smaller aperture? Maybe I'll try some pics wide open and compare them tomorrow.

 

[reflecx]

Hi reflecx,

I was shooting at f13. Is this sufficient, or should I use a even smaller aperture? Maybe I'll try some pics wide open and compare them tomorrow.

f13 is more than sufficient. Something else might be causing this lack of contrast. Maybe someone who owns this lens can help.

Here is the picture at 300mm with it's contrast slightly enhanced.

 

[lanxx]

It looks like the pic is a little softer.
Use F8? should be better.

Used to own this lens, played quite a bit with it, it's
like that at longer foal length.
Are you using a filter? if it's those cheaper ones, it sort of
soften the pics to a very small extend.

Also, try shooting on a tripod when >200mm, it tends to shake a bit.
I tried using the tripod, quite sharp pics.

Shot using the same lens at around 150mm without tripod.

Shot using the same lens at around 200mm with tripod.

 

[sulhan]

Hi there...(one possibility of the low contrast)

Just to share my previous experience on examining and the lens. I have owned this lens before the previous model before this which has same glass architecture design.

This lens is a great buy and gives very good color in high saturations.

Problem...

The internal rear element may fog up upon usage. The explanation for this fog is due to the vapourised grease. The grease comes from the camera internals. I have seen some of these lens in 2nd hand shops and if you examine closely at maximum zoom at 300mm, the 2nd/3rd (if i'm not wrong) last element inside under a light source and focus your eyes in these last few lens group, there may be small dots of vapor deposition.

Not sure howlong you may have used the lens or how you have used it.....well, mainly the plastic housing of this lens is simple plastic and the lens module inside is modularised (i've dismantled one apart before to examine the internal gearing system and electrical contacts).

Looks like most parts are plastics. Therefore....if you use this lens often in HOT sun where the lens body gets very warm....this fogging occurance may
have a higher tendency to occur through time...as he glass is cooler in the system hence the vaporised grease will condense on the glass - maybe the fact that most ppl keep lens in the bag when len still warm...with lens pointing down then the condensation will happen at the rear elements...

Therefore ....do check out this lens for the fog as above, if you do see the tiny dots....then i think is best you send in to sigma for cleaning.....hopefully u don't juz get rid of it in Buy & Sell as this problem will then be passed on to another user and the problem will stay.

I Believe...Sigma do offer cleaning at a reasonable price...

rgds,
Sulhan

 

[mpenza]

was it simply because the len hood was not used or there's an overexposure?

 

[bernards]

I used a tripod, but didn't take great care. The UV filter is a B+W MRC, metering was on matrix. I always attach a lens hood, unless I am using a flash. I had this problem brand new out of the box.

lanxx, I did some tests. I shot the same scene fromt he largest to the smallest aperture. All returned the same results.

sulhan,

Thanks for sharing your expeience. I guess if the lens will keep fogging up when used in hot environments, making it not suitable for countries like Singapore? Actually, your experience is consistent with the a comment on nikonians, but without the cause. I'll send my unit back to Sigma for a look and see what they say.

 

[bernards]

Update.

I just dropped my lense at Sigma for a check-up. I described the problems to receptionist? She claims it doesn't sound like a common problem. She took the lense and said the techs will do a check. Since my lense is so new, they might do an exchange if they find a flaw with it. Unfortunately it'll take a week.

 

[teerex]

Update.

I just dropped my lense at Sigma for a check-up. I described the problems to receptionist? She claims it doesn't sound like a common problem. She took the lense and said the techs will do a check. Since my lense is so new, they might do an exchange if they find a flaw with it. Unfortunately it'll take a week.

bernards - hope your problems can be solved by them. Can you share the outcome with other users of that lens.

 

[sulhan]

Update.

I just dropped my lense at Sigma for a check-up. I described the problems to receptionist? She claims it doesn't sound like a common problem. She took the lense and said the techs will do a check. Since my lense is so new, they might do an exchange if they find a flaw with it. Unfortunately it'll take a week.

Great that the lens is send in for medical check-up......1 week.....its normal....if your are lucky they will call you before 1 week....in cases where parts need to be replaced and obtained from overseas..then probably they will call you to tell you they will take a little longer....

rgds,
sulhan

 

[jbma]

I have this lens but do not encounter the problem that you described. The lens has a warm tone but I like it. It is pretty sharp and light.

 

[bernards]

I'll keep this thread updated on the progress. I do hope it's an exception lemon.

 

[teerex]

I'll keep this thread updated on the progress. I do hope it's an exception lemon.

Thanks bernards. Hope you've got a lemon too, so that you can get it changed and enjoy using the lens.

Cheers

 

[lanxx]

Hope it is a small prob! Gd luck