[paperbag846]

Hello everyone,

I have a simple question. I recently picked up my first new lens for my first dSLR, a K20d. The kit lens was nice, but I found it weak at the edges. After a lot of research into affordable lenses, I found an SMC A 28mm f2.8 for 100 CAD.

So far I have been very happy. An improvement in bokeh and it is a full stop faster than my kit lens at 28mm. I bought it to get higher quality images, and less noisy indoor ones, at a low cost. I have been satisfied except for something new - a problem I do not have with my kit lens.

Here is an image I threw together. I know that veiling flare can be reduced by stopping down, so I stopped down to show you how it reduces flare in this situation. However, the veiling flare is not eliminated.

A couple of things: I realize this is a very chalanging shots for any camera and I also realize that I am essentially setting this lens up to fail by doing this test. But my kit lens does not exhibit this kind of flare and I would like to know why I am seeing this, and if I should be expecting to see this.

In many cases this lens performs better than my kit lens, but if there is anything I can do to tackle this specific problem, I would like to know what it is! The lens is free of grease and other residue as far as I can tell.

Is there something wrong with this lens or should I expect this kind of performance from a 1980's SMC A prime?

P.S., A confession - I actually like the way this glare can look - sometimes. But I want to know how to get it under control.

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Last edited by paperbag846; 10-27-2010 at 11:57 AM.

[NaClH2O]

Basically, I would say "yes you should expect more flare" The reason for this being the lens glass coatings. The kit lens coatings have been optimized for the way a digital sensor performs, whereas obviously the much older "A" 28 hasn't got that.
One question: Did you use a circular polarizing filter on these shots? If not try that and see if it makes a difference. Also experiment with different hoods. I have a Sigma 24mm that flares something terrible with a "wide angle" hood on it but does quite well with a "normal" hood, and there is no vignetting with the normal hood.
If you are using a UV "protection" filter ... lose it, it will certainly contribute to flare.

NaCl(my two cents of input and worth all of it)H2O

[drougge]

Another possibility is reflections from the area around the rear element. Painting this (carefully!) to be less reflective may help. (Depending on how it looks, obviously.)

I'm sure you're getting reflections from the glass as well, but the rear element on 28mm lenses tends to be fairly small, so you probably have quite a lot of area around it that you could paint. Make sure the paint is really dull though, or you'll make it worse instead.

Actually, don't do it at all, just think about it.

[paperbag846]

Great, thanks for the help.

No UV filter, I learned the hard way to not rely on those for protection by runing some fantastic shots with my other lens. I will seek out a polarizing filter, but first a lens hood.

However, would a hood stop flare like this?

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Last edited by paperbag846; 10-27-2010 at 11:57 AM.

[NaClH2O]

You'd be surprised at how incidental light gets into, and bounces around in a lens. It has been proven that even indoors a hood will increase contrast which in turn brightens colors. The nice things about hood are:
a: they are cheap
b: they help protect the front element
c: the bayonet ones are self storing and the rubber ones collapse in storage
d: can be used in a pinch as a wide mouth funnel
e: they make you look like a geek and geekiness is now considered sexy

NaCl(sorry, got a bit carried away there...as you can see, I like hoods)H2O

[paperbag846]

Sounds like a good idea about the painting - but I doubt in my case it would be worth the risk.

Any advice on lens hoods? I can't find the official lens hood anywhere, but can you sort of just throw any hood on a lens as long as its the right diamater?

[Steinback]

I use a hood designed for a 50mm lens on my A28mm without any trouble, but I have to remember to remove it before using the lens on my film cameras. Any 49mm threaded hood designed for a 50mm or shorter lens on film will likely work. There are a number of threads on the forum discussing people's hood preferences.

[Aristophanes]

Sounds like a good idea about the painting - but I doubt in my case it would be worth the risk.

Any advice on lens hoods? I can't find the official lens hood anywhere, but can you sort of just throw any hood on a lens as long as its the right diamater?

Yes. For the 28mm (I have the stellar M 28/3.5 version) I use a $7 rubber, screw-on lens hood (not a wide angle one for 28mm--just a regular one). No UV glass for me, but I carry a circular polarizer at 52mm with a step-up ring. Wouldn't help in the shot you demo in post #1, but at 90 degrees the CPL plus lens hood (always) makes a lot of difference. For the other shot, hard to tell. You're clearly getting some awkward window light. I'd try a -1 EV on that shot (not knowing the EXIF).

[paperbag846]

Yes I find that many of these flares can be minimized if i don't overexpose .

I really appreciate the help. I was worried that there might be something wrong with my lens. If this is what I should expect then I am happy!

[Marc Sabatella]

You *can* throw on just any hood that fits, but some will be more effective than others, and some will vignette. I tried a couple different rubber collapsible hoods with my 28, and neither was very effective at all. I tried a metal hood that was quite effective at reducing flare, but vignetted a bit. Purely on a whim, I tried the DA70 hood in its collapsed position, and found it worked *perfectly*. So that's what I use now. Not that this helps you if you don't the DA70. but the moral of the story is, no, don't exepct just anything that fits to be worth whatever you spend on it. I'd try out some hoods in a camera store if at all possible.