DA*50-135... Why get the DA*300?

Pentax_XTC · 09-27-2009, 10:37 PM

I was experimenting and took 2 photos. One with my DA*50-135 & one with my DA 18-250 both at maximum zoom. When I look at the images I can only tell a slight angle of view difference between the two. So my question is, with the difference in the angle of view getting smaller and smaller as the lens lenght gets bigger and bigger, is the DA*300 going to make that much of a difference over the 50-135? I mostly would use the telephoto range for street photography.

Thanks,

*heliphoto* · 09-27-2009, 10:48 PM

My guess is that you were focused on a fairly close subject - maybe 10 or 15ft.? I remember that the 18-250 exhibits a significant shortening of focal length when focused closer than infinity (a trait common to many internal focusing (IF) lenses (all of 'em?)). If my guess is correct, try it again with a focus point near infinity - you ought to see a pretty significant difference!

The same object shot with the 300mm should be over twice as big in your image as that same shot taken at 135mm (if my understanding of focal length relationships is correct - which is questioable

).

philbaum · 09-27-2009, 11:30 PM

The 18-250 shrinks to as low as 188mm on my lens when its focused relatively closely.

I can't image the DA 300 as being too useful for street photography, there is nothing discrete about it due to its length, and its got to be a little intimidating for the person its pointed at.

Pentax_XTC · 09-28-2009, 05:29 AM

I was focused in on something about 10' away. Interesting, I have not heard about this shortened length when focusing closely with the 18-250. I'll try again later today on a subject much further away.

Out of curiosity, does anyone have a link to a lens length/angle of view graph or table?

The main thing I'm trying to find out here is if it will be worth it for me to drop the $1100.00-$1200.00 in about 6 months or not. I'm not concerned about the length being obvious for street work, I'm just looking for a longer reach that would double or more the reach of the DA*50-135.

legacyb4 · 09-28-2009, 07:18 AM

Having picked up a DA 55-300mm for soccer use, I'd have to say yes, it definitely does make a difference for being able to get in closer to the action on the far ends of the field.

philbaum · 09-28-2009, 11:31 AM

Originally Posted by Pentax_XTC

I was focused in on something about 10' away. Interesting, I have not heard about this shortened length when focusing closely with the 18-250. I'll try again later today on a subject much further away.

Out of curiosity, does anyone have a link to a lens length/angle of view graph or table?

The main thing I'm trying to find out here is if it will be worth it for me to drop the $1100.00-$1200.00 in about 6 months or not. I'm not concerned about the length being obvious for street work, I'm just looking for a longer reach that would double or more the reach of the DA*50-135.

The DA 300 will fit those requirements. And its F4. The 18-250 very quickly gets to F6.3 when its out at max tele. And thats when you need a faster shutter to get a non-blurred image. It weighs 34 oz, excellent contrasty images and great bokeh if that matters. And its water proof/resistant whatever. And its handholdable, it easily doubles the 50-135. It also gets great images when attached to a 1.4 Tamron TC but you loose a stop of light with the 1.4 so i don't normally use it. Also, i think these lenses have good resale value so you would not have a problem selling it, but i'm keeping mine :-) The con to this lens is you need a backpack style bag to carry it, or perhaps a special holster style.

As the poster said, i've heard good things about the DA 50-300. i don't have it so can't speak to it. Undoubtedly its esier to carry and store.

Pentax_XTC · 09-28-2009, 01:15 PM

Originally Posted by philbaum

The DA 300 will fit those requirements. And its F4. The 18-250 very quickly gets to F6.3 when its out at max tele. And thats when you need a faster shutter to get a non-blurred image. It weighs 34 oz, excellent contrasty images and great bokeh if that matters. And its water proof/resistant whatever. And its handholdable, it easily doubles the 50-135. It also gets great images when attached to a 1.4 Tamron TC but you loose a stop of light with the 1.4 so i don't normally use it. Also, i think these lenses have good resale value so you would not have a problem selling it, but i'm keeping mine :-) The con to this lens is you need a backpack style bag to carry it, or perhaps a special holster style.

I have the Kata 3N1-30 and it should fit fine. I am actually looking at the DA*300 due to the weather sealing, f/4, and high quality glass. I just have to get past the fact that it's not a zoom lens. As you can see from my signature they are my preference.

I just wish that Pentax made a 100-300 DA* zoom. That would be perfect!

Originally Posted by Stratario

I already discovered a small error. Here's a revised copy of the FOV chart.

Thanks! This is very helpful!

I did go outside on lunch today and try focusing on a far away tree line and the angle of view from 135 to 250 was much more apparent to me.

*dadipentak* · 09-28-2009, 01:49 PM

Very interesting chart, Stratario--thanks!

The DA*300mm (especially coupled with a TC) is great for wildlife but I have to agree it's a bit much for street photography.

*heliphoto* · 09-28-2009, 01:54 PM

Stratario... er... Fred, that's a very useful chart. It deserves it's own thread.