Lens flare in '80s lenses

[petebown]

I've been buying a few old bargin lenses on the 'Bay lately... Just building up a cheap SLR kit for the kids to use (and me of course!)

I received a Pentax-A 28-80mm f3.5-f4.5 zoom lens in the mail today and was immediately horrified at the amount of flare that this lens suffers from. I could see a problem through the viewfinder and a test film confirmed my fears.

I must admit that I have been rather spoilt lately... I've used nothing but Voigtlander rangefinders and lenses for the past three years, so the sight of purple streaks and loss of contrast is foreign to me!!!

Is such lens flare common in mid '80s zooms. I did use such lenses back in the '80s so I expected a little more from this lens and I'm not sure whether its a design 'issue' or whether the lens is faulty or just past its sell-by date. The lens is not mint condition although the elements look OK with no fungus or dust. There is a 'silver spot' on the edge of one of the elements inside the lens that may be causing the problem. I'm not sure what the spot is... I looks like a spot of solder about 1mm round... Could be element separation???

Maybe I'm just being fussy, but I don't think this lens is good enough for the kids to use let alone me.

 

[Michel Hardy-Vallée]

Not to bring you too much towards the dark side, but why don't you just buy some prime lens in K mount? They're still plenty, cheap, and will give you a better image than any but the highest-end zooms. Plus you get the kids to have to think about composition and the relation to their subject.

The ultimate K-mount reference site is :
http://www.bdimitrov.de/kmp/

 

[petebown]

I totally agree. I've already bought a Tamron 200mm f3.5 for the camera - its a really nice lens... I really didn't want a 70-210 for that reason. I'm regretting 28-80 zoom big time. I want something the kids will be able to use, but may now go for a 50mm, then later a 90mm and a 24mm.

My Voigtlander already uses prime lenses - 25, 35, 50 and 90mm, so I'm already converted to the dark side I'm just horrified if this 28-80 is operating correctly - its awful!!!

 

[Michel Hardy-Vallée]

Well, I'm sure someone more knowledgeable than I will chip in, but I know that zooms have been considered crap for a while until recently (the exception would perhaps be cinema zooms).

Glad you're bent on primes! I do like the smaller lens factor and the fact that I don't have to decide whether I move or I zoom. I've been working with a zoom on a d*g*t*l camera recently for a photo shoot at my job and I had to consciously set the zoom to a specific f-length to know what I was doing. Otherwise I would get confused as to how to take the picture...

 

[David H. Bebbington]

As far as I am aware, there have been few major improvements in lens flare performance since super multi-coating (SMC) came in in the 1960s. You should therefore expect a 1980s lens in good order to perform almost as well as a new one.

Zooms will always flare more than prime lenses, zooms I have owned (including the model you have) tend to flare more at one particular focal length setting, of course flare is most pronounced with a light source in the picture and frequently at its worst with a light source just outside the picture area. If you are getting flare in other situations. there is definitely something wrong with the lens. Are you using a lens hood? If you are getting flare at a telephoto setting, a roll-up rubber lens hood can be handy, you can make this longer for the 80 mm setting and fold it back for wide-angle.

 

[gnashings]

Most of my lenses are from the 70's and 80's, and although I don't have specific Pentax experience, I have used both Canon and Nikon lenses, as well as a variety of Russian glass. Overall, I have not had problems with flare except with 3rd party (read: cheap) wide angles. I am huge fan of 50mm lenses for 35mm cameras. You simply can't get more bang for your back or flexibility. These lenses are likely to be the fastest lens in your kit (unless you sell off some vital organs), and most manufacturers really seem to have the designs dialed in, so the optical quality is usually very good . I suggest that a good 50mm will give you much joy and very few problems. Even the very budget-oriented lenses I have (Canon f1.8 SC, Nikon E series) seem to be reasonably free of flare and very sharp in most settings. As has been already mentioned, a cheap rubber hood is a great idea - you will have no issues with flare and it makes a great "bumper" for when you are being less than careful (or when your kids have the camera). I think you will probably find that a 50mm spends a lot of time attached to your camera and brings you much fun and some great results!

Peter.

 

[Ole]

Zoom lenses have a lot more elements than prime lenses. And not only elements, but glass/air surfaces. Even with a very good SMC (like Pentax'), there will inadvertently be more flare in zoom lenses than in a prime at the same focal length. Add to that that wide angle lenses are more flare-prone than longer focal lengths; and flare in a wide-angle zoom should not come as a surprise!

 

[Christopher Walrath]

Actually there have vast advances since the 70's in lens element construction. Late 80's, early 90's the manus began to make quality zooms with dispersion glass, glare reduction, superior coating materials, less elements for reflection, etc. In the 80's it truly was a case of what you bought was what you got. Pay for a mint and get a lens of substance, pay ten buck and it might as well have plastic elements.

 

[petebown]

I'm going to try using this lens with a lens hood to see if it makes any difference. The front element is very close to the front of the barrel, so its no wonder it suffers from so much flare. Trouble is, the front element turns, so a petal hood will be a pain to use and I dislike rubber hoods. The problem is more accute at the 80mm end. At 28mm the lens displays purple streaks which are easy to see in the viewfinder. At the 80mm the lens just loses contrast and a deeper hood is required to prevent this.

However, I think I will invest in some prime lenses. I might risk an SMC 35-70mm with a lens hood, to see if its any better.

 

[Struan Gray]

pete, look for the 'A' 35-105 f3.5 fixed aperture zoom. It's the only affordable zoom I have ever found that gave a similar flare-free sparkle to that produced by smc primes. Well worth the bulk and weight, and you can always carry a 28 f2.8 in your pocket for when you need something wider.

 

[petebown]

pete, look for the 'A' 35-105 f3.5 fixed aperture zoom. It's the only affordable zoom I have ever found that gave a similar flare-free sparkle to that produced by smc primes. Well worth the bulk and weight, and you can always carry a 28 f2.8 in your pocket for when you need something wider.

Many thanks! There's one on eBay at the moment! I'm not too bothered about the wide angle end... I personally prefer 24mm to 28mm. 24mm lenses have a little more impact without the nasty effects that you get from ultra wides.