[KC0PET]

I recently bought a used Sigma 24mm f2.8 Mini-Wide II. I have 2 problems, not sure if they are related or not.

The first is flare. I see in the reviews that some reviewers say this lens is prone to flare. I find the flare objectionable and it also seems to create a haze or fringing around bright areas. In a nice evenly lit scene it is fine and seems to be a sharp lens otherwise.

A couple example photos are attached.

The second is that I have to underexpose by about 1 1/2 stops to get a good exposure, particularly in outdoor shots like the scene attached with red bush. A good, evenly lit situation it is not as far off, but still requires underexposure. I am using a K20D. I do find that I often lean to underexposure with my other lenses also but maybe 1/2 stop typical.

So I am just seeing if anyone has thoughts. The flare problem could be just a characteristic of this lens? Is there a way to calibrate the exposure if it is off?

Thanks in advance.

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Last edited by KC0PET; 12-14-2015 at 09:26 PM.

[pepperberry farm]

pfft... flare.... I have a copy of this lens; I am actually using it in the Single in October challenge this month and have learned a ton about it...

yes - this lens is very susceptible to flare; the hood helps some, but not much... I've learned the simple fact of not allowing any stray light any where near it...

I didn't seem to notice the overexposure issue unless it was hand-in-hand with flare..

here's my Flickr album with the Mini-Wide II:

https://www.flickr.com/photos/133285589@N05/albums/72157657310909304

[CarlosU]

I have one since film days (early 90s if I remember well). I've seen the same exact two issues.

The lens consistently overexposed around 1 stop on film cameras and also now with my DSLRs, I always use it with -1 stop exposure compensation. I have thought it could be a slow diaphragm but it also occurs when shooting wide open. Weird...

The flare issue only appeared when I started using DSLRs. It appears when there are strong light sources within the picture. I think it is an example of old coatings dealing with digital sensors. The strong lights in the image are reflected from the sensor to the back of the lens and then back to the sensor, creating the diffused color patches. Modern lenses have better coatings on the back element to avoid this. That's what I think.

Otherwise, a nice sharp lens with good close-focus abilities.

[johnhilvert]

I have seen similar flare on shots with lens that have UV filters on them sometimes.

On wide angle lenses at small apertures, depth of field might be large enough so that you'd see optical degradation from the filter due to a scratch or blemish.

If you are using a filter. Try taking a shot without it to see if it improves the situation.

[VisualDarkness]

I think it looks like separation, haze of fungus due to the blooming. How you shone light trough it and checked?

[JohnX]

Whilst the second shot could be evidence of flare, the first isn't. There's something else going on. Do you have a filter on the lens?

[KC0PET]

Thanks for the responses! This mostly confirms my suspicions. I have tried the lens with a skylight filter, a c. polarizer and without any filter and can't really tell any difference. i also have checked thoroughly and cannot see any fungus. Although the coating on the front element shows signs of heavy cleaning and I wonder if that is not adding to the flare problem.

Anyway, I may keep it and just learn to use it and knowing me will probably end up with another 24mm or 2 of different brands anyway.

Rick

[fg-one]

A few years ago, I used this lens to take a photo of my daughter on her birthday. The flares of the candles were all over, including on her face. This is when I decided to buy a DA21. I still use the lens outside where it gives suitable sharpness for landscapes but I avoid facing strong light. Regarding exposure, my experience is that you rarely get accurate exposure when using third-party lenses in A mode. This includes more recent lenses than the Sigma MiniWide. I don't know the reason for this but I have had the same problem with Voigtländer lenses. The only way out is to get to know your lenses and correct the exposure accordingly.

[Just1MoreDave]

It should be a SuperWide II - the MiniWide II is the 28mm lens.

Mine has fairly accurate exposure. Sigma made lots of versions with the same optics. Mine looks like this:



Older ones look like this:



I had another Sigma KA mount with that older style focus ring and weird exposures, so I wonder if the older ones aren't quite right.

The OP's example shots look like something else is going on, like oil on a lens surface.

[KC0PET]

Thanks for the info. Yes it is a Super-Wide II (typo error on my part). Mine looks like the older version.

After looking back on other photos taken with those reflective yellow jackets that same day with a different lens, I am thinking that may be a flare problem. The silver striping on those jackets is very reflective and photos taken with a different lens that does not have much flare issue has a similar effect, just not as pronounced. Interesting also, I shot quite a few flash photos with an old, non-ttl flash and the jacket striping was throwing the flash exposure off by about 2 stops.

Also thanks for the comment about the third party lens A-mode, that explains a similar problem I have with a Vivitar 28mm lens that I have.

[pepperberry farm]

ah - then scratch my commentary about the Mini-Wide II, then...

(:

[osv]

The second is that I have to underexpose by about 1 1/2 stops to get a good exposure, particularly in outdoor shots like the scene attached with red bush. A good, evenly lit situation it is not as far off.

you will never have a good evenly lit situation with that red bush shot, because you have the sun fully in one corner, and you've completely blown out the shot with it... look at histogram of the highlighted area, it's totally crushed on the right-hand side.

the yellow jacket shot is also so blown out from overexposure that it's showing big patches of white, not yellow... the histogram is crushed hard on the right in those white areas.

this is operator error, not a lens problem.

yes, it's no doubt compounded by the weak d.r. of an old k20d, but that just means that you need to learn how to shoot around the issues.

the sigma superwideii lenses are about the best 24mm lens that you'll find for your pentax.

[KC0PET]

OK thanks for the response. What I did not post (or explain) is that I shot the same scene with a different lens and a p & s camera and also I bracketed over about a 5 stop range. The other lens on my K20D and the p & s did not blow out the image quite like that. Unfortunately the p & s handled the situation the best, but it is a much newer camera with probably a more advanced sensor. The sun is in the photo by design, not by accident. I like to shoot that type of photo at times and I usually like the effect of the flare. But also, there are other situations with this lens where the sun is not directly in the photo, just scenes with a lot of light to dark range where the flare type effects occurred when I was not expecting that. I can get rid of the flare effect, but then the overall photo is badly underexposed.

I suppose the summation of this is that I just don't like the way this particular lens/camera combination handles this type of shooting. Back in my days of film shooting I shot photos like this, in fact there is one on the wall here (most likely shot with Kodachrome 64 - I have no idea which lens, but more than likely it was an Olympus lens from the '70s or 80s). As you pointed out I will just have to work around the issue. Perhaps I need to get a newer camera...

Another thing I am wondering if I was to shoot raw, if I could tinker with the images to my liking. I have not ventured into the world of raw yet, but that will come in time.

Anyway I would prefer to call it a "shooting style" rather than "operator error" :-)

[osv]

what you are doing is exposing for the shadows, when you need to expose for the highlights instead.

dark areas can be recovered to some extent, but the blown-out overexposed areas in those pics are gone for good.

that's why the yellow jacket has big spots of white... the yellow color is permanently gone.

the sigma superwideii may or may not have a flare issue, but this thread isn't about flare at all... those shots are bad because they are severely overexposed.

photographers have to learn how to recognize overexposure, and how to correct it with the camera settings... it's a struggle that never goes away, with any camera gear.

[VisualDarkness]

osv is right, expose for the highlights instead when shooting digital.