[Kaelee]

Hi, I'm new to photography and recently purchased a pentax K10D and it came with a pentax M 50mm f1.7
Most of the photos are turning out really well but im noticing some strange aberrations in my photos.
IMGP2406 - Kaelee's Album: night market - PentaxForums.com
Can Some one tell me what these aberrations are called and how can i prevent them?

Thanks

[Bukaj]

Your link does not seem to work. At least on my computer.
I often use the same combination (K10D + M 50 1.7) and there are some aberrations, but stopping down usually helps...

[TomB_tx]

A right-click and "open image in new tab" got me to the Flickr collection of night market, I don't see anything to complain about. A few of the high-contrast lights have a small amount of fringing, but that's possible with any lens. I like the 50 1.7 M better than any other Pentax "normal" lens.

[rawr]

This is the image OP posted in their gallery:



I see some purple fringing around one of the lights - is that what you mean as an 'aberration'? It's sometimes hard to prevent, but stopping down can sometimes help. It is also relatively easy to clean up in post-processing using software like Lightroom.

[Adam]

This is the image OP posted in their gallery:



I see some purple fringing around one of the lights - is that what you mean as an 'aberration'? It's sometimes hard to prevent, but stopping down can sometimes help. It is also relatively easy to clean up in post-processing using software like Lightroom.

Generally older lenses exhibit more fringing than lenses designed for digital, but what's in the photo above seems completely normal. However, you do have some lens flare in there because of the two bright lights- again, mostly blame the older lens coatings.

[TomB_tx]

However, you do have some lens flare in there because of the two bright lights- again, mostly blame the older lens coatings.

That's not flare! THIS is flare - intentional. (Canon FL 50 f1.4 on Canon FT from 1967)

[Kaelee]

Thanks a lot. Im new to this forum and i didnt know how to post the image properly and it some how screwed up.

[THoog]

I think what Adam (and the OP) are referring to are the green blobs about a third of the way up from the bottom of the image. Definitely look like lens flares, caused by the bright lights reflecting off the elements inside the lens - unless there a pane of glass in front of the man, or fliter on the front of the lens. Modern coatings do help with flare, but very few lenses (unless they are quite expensive) are 100% flare-proof when shooting directly at bright light sources.

[TomB_tx]

Right about the green blobs being from the lens - but with the terminology we used in the 70s, that's internal lens reflection, not flare - flare being a smearing of light. Actually I wonder if the OP had a filter on the lens, as it looks like a flat-surface reflection, and I've seen more of that from (non multi-coated) filters than anything else.

[Kaelee]

The lens came with a filter when i bought it second hand so I decided to keep it on to protect the front lens element. i just looked up "filter flare" on Google and it looks like that's what I've been getting.

I've already heard to keep a UV filter on a lens, not to filter out UV, but just to protect the lens element. should i continue to use UV filters? (given that i use higher quality filters) of should i just leave the filters at home?

[rawr]

should i continue to use UV filters?

No no no. Only use a filter if you need it.

They can, in particular, cause lots of problems at night.
My M 50 1.7 HATES UV filters.

EDIT: the heavy image crop below is an example of the problems I would see when using a UV filter on my M 50 1.7 at night... in real life, there is not supposed to be a window there, floating in the sky.

[elliott]

I've already heard to keep a UV filter on a lens, not to filter out UV, but just to protect the lens element. should i continue to use UV filters? (given that i use higher quality filters) of should i just leave the filters at home?

A hood will protect your front element from anything touching it in most cases and also improve image quality. A $5 hood is a much better investment than a $50 UV filter unless you are in a situation where things might be flying directly at you and could hit the lens.

Ironically, I use a bunch of old UV filters with the glass smashed out to determine the optimal length of a lens hood for a particular lens. For a while I used these as my only hood. Another good use for some cheap UV filters is to make a white balance tool, just sandwich a piece of white coffee filter between two of them and you have a good substitute for an Expodisc, it works the same way.

[lgbalfa]

how do you prevent the "green blobs"?

never noticed it on my *ist DL but see it a little more often on my new k-50.

[pishta]

Rawr, nice shot of "Heaven's Gate"! UV filters are not needed on digital cameras, and if used, may introduce unwanted internal reflections such as what the poster is describing. These should be visible in diopter or live view to confirm its the filter and not an internal element.

[stevebrot]

fliter on the front of the lens

Yep, filter...


Steve