[Deuce808]

I've been thinking about picking up a K50 used locally just for the fact of Pentax's 6 point starbursts.

My questions are, if I wanted to have a weather sealed lens as well as 6 blades does the 18-55 wr and 50-200 wr both produce sharp 6 point stars? I have seen some shots at f8-f11 which are ok but not crisp, also I notice at f22 some defraction turns the star points into double points.

So is f14-16 the sweet spot?

Or should I go with a prime, say the 35 2.4 and just watch out for rain?

Thanks

[jbinpg]

The rule is that an even number of aperture blades on a lens will produce the same number of starbursts as blades. An odd number of aperture blades will produce 2 x number of starbursts as blades.

[Deuce808]

But is there a f stop where the burst itself is sharper? I have nikons that produce great bursts but those are 7 and 9 blades which provide 14 and 18 points. Sometimes very distracting. I had a old manual Nikon that had 6 pointed stars but was very prone to lens flare.

All I want to know if I pull the trigger on a Pentax is if the kit wr lenses provide sharp stars or if there are better options with 6 blades.

Thanks

[victormeldrew]

Am I right in understanding you're thinking of buying a whole body and lens kit in search of starbursts? Surely you can find a suitable lens for a body you already own? The body has nothing to do with it...

Anyway, you might find an answer here:
https://www.pentaxforums.com/forums/10-pentax-slr-lens-discussion/310177-best...st-lenses.html

[AquaDome]

Am I right in understanding you're thinking of buying a whole body and lens kit in search of starbursts? Surely you can find a suitable lens for a body you already own? The body has nothing to do with it...

Anyway, you might find an answer here:
https://www.pentaxforums.com/forums/10-pentax-slr-lens-discussion/310177-best...st-lenses.html

I think the OP is looking for a body with WR. The K-50 is a great choice.

The more you stop down the aperture, the better the starbursts.

[Scorpio71GR]

I've been thinking about picking up a K50 used locally just for the fact of Pentax's 6 point starbursts.

My questions are, if I wanted to have a weather sealed lens as well as 6 blades does the 18-55 wr and 50-200 wr both produce sharp 6 point stars? I have seen some shots at f8-f11 which are ok but not crisp, also I notice at f22 some defraction turns the star points into double points.

So is f14-16 the sweet spot?

Or should I go with a prime, say the 35 2.4 and just watch out for rain?

Thanks

The DA 35 would most likely to give better starbursts that the DA18-55 zoom. I have the DA 35 but have never used it at night. The DA 50 1.8 would not be a good choice due to its rounded blades. The newer HD and DAL 18-50 WRE would not be best either since they have rounded blades as well. Typically I shoot around f11 or so for starbursts but it varies by lenses and light conditions. The DA 35 is a very sharp lens so it should do pretty well. Maybe I will have to give it a try myself.

[victormeldrew]

I didn't notice that WR is essential.
The DA35 is not WR either. Apart from the cheaper kit lenses I'm not sure I know of a WR lens with 6 straight blades...

[jatrax]

The Pentax Lens Database search function allows you to search on lenses by number of aperture blades. See here: Search - Pentax Lens Reviews & Lens Database

[Scorpio71GR]

I do not believe there are any. All the DA* lenses have 9 blades. Pretty much all of the newer lenses have round blades.

[Deuce808]

I think the OP is looking for a body with WR. The K-50 is a great choice.

The more you stop down the aperture, the better the starbursts.

Thanks, yes, weather sealing is a must. I forgot to mention low cost. The Pentax k50 + lot zooms provided both. I would never take my Nikon out in a drizzle since it cost 10x more no matter what they say about weather sealing. I have the chance to get a k50 + 18-55 wr for $200, but wanted crisp stars out of it.

[Deuce808]

The DA 35 would most likely to give better starbursts that the DA18-55 zoom. I have the DA 35 but have never used it at night. The DA 50 1.8 would not be a good choice due to its rounded blades. The newer HD and DAL 18-50 WRE would not be best either since they have rounded blades as well. Typically I shoot around f11 or so for starbursts but it varies by lenses and light conditions. The DA 35 is a very sharp lens so it should do pretty well. Maybe I will have to give it a try myself.

Thanks for the tip on the wr zoom blades vs the 35's blades. I couldn't find a reference anywhere on that.

[Deuce808]

The Pentax Lens Database search function allows you to search on lenses by number of aperture blades. See here: Search - Pentax Lens Reviews & Lens Database

Thanks, I will check this out!

[Deuce808]

I do not believe there are any. All the DA* lenses have 9 blades. Pretty much all of the newer lenses have round blades.

Figured...I dislike the trend for rounded blades although I understand the reasoning.

[calsan]

6 blade lens will produce the appearance of a 6 point starburst, but it won't be sharp looking. This is because it's actually made up of twelve points - a six pointed starburst closely overlapping another six pointed starburst.

A seven bladed lens will produce a nice, sharp 14 pointed star with all the points evenly spaced.

So - to get nice sharp starbursts, you acutally want a lens with an odd number of blades.
The DA limiteds all have this 'feature' with either 7 blades in the wider lenses and 9 in the more telephoto lenses.

See the photo below - notice that there are actually 12 points from this shot (cropped) with the six bladed 18-55.

[swanlefitte]

Do a search for starburt and the best starburst thread talks and shows a lot of lenses and info on Pentax lenses. Not just 6 blade tho.