Forgot Password
Pentax Camera Forums Home
 

Reply
Show Printable Version Search this Thread
11-07-2013, 01:59 PM   #31
Pentaxian
tromboads's Avatar

Join Date: Apr 2012
Location: Melbs
Photos: Gallery | Albums
Posts: 1,148
QuoteOriginally posted by Andi Lo Quote
Changing focal lengths does not change perspective in a meaningful manner. Perspective can only change from subject to camera distance.
https://www.pentaxforums.com/forums/10-pentax-slr-lens-discussion/184570-len...l-frame-2.html

By buying K-3 and keeping his current stable of lenses, he intends to acquire higher FL by cropping, but I'm guessing he doesn't intend to move closer to his subjects (or farther). When DOF is taken out of the equation, cropping is exactly the same as zooming. Try out the example posted in that thread, shoot at 200mm then at 10mm, but dont move your camera, then crop the 10mm image to look like 200mm. Resolution and DOF aside the images will look exactly the same.

When you change FL, perspective only changes because you have moved your camera in order to keep the same framing, not because the FL changed

I did just that.. World view... Changing..

*Suddenly feels he would only ever need a D800 with a 35mm

11-07-2013, 02:23 PM   #32
Senior Member




Join Date: Sep 2006
Location: Plano Texas USA
Posts: 121
QuoteOriginally posted by normhead Quote
OK, try again…

Sigma 70-300 @ 300mm uncropped on K-3



A-400 uncropped on K-5


K-3 with Sigma 70-300 cropped to K-5 image size.


While the 300 on the K3 is marginally bigger than the K-3 image, the K-5 and 400 image is still the biggest.

Crop both to 2200 pixels, then export at 1024

K-5 - 400mm


K-3 300mm


Conclusion:
You can't make up the difference between shooting with a 300mm lens and a 400mm lens by shooting with a K-3, maybe a 300 to a 350.
there is noticeable CA on that Sigma, I'd keep the DA*300 and get the K3 and let the K5 go

(I know he's not looking at the sigma 70-300, but how does the 500 he's looking at compare? does it have CA?)
11-07-2013, 02:25 PM   #33
Veteran Member
Dr_who's Avatar

Join Date: Jun 2009
Location: Edmonton, Alberta, Canada
Photos: Gallery | Albums
Posts: 690
I think you should get the lens as it'll be with you longer than any camera body of the digital age, and if the time should come where the K3 drops below X amount you can get it or the next latest camera out there.
11-07-2013, 03:17 PM   #34
Veteran Member
Andi Lo's Avatar

Join Date: Jul 2008
Location: Halifax, Nova Scotia
Posts: 2,925
QuoteOriginally posted by tromboads Quote
I did just that.. World view... Changing..

*Suddenly feels he would only ever need a D800 with a 35mm
I know right, that thread really need to be stickied I had the wrong impression that going FF will help me alleviate broad shoulders in UWA people shots since the FL is longer. How stupid was that!

Thank you for the test shots normhead, it confirms in pictures what I thought I knew about getting more "reach" using MP FL > TC > MP

11-07-2013, 04:01 PM   #35
Pentaxian
tromboads's Avatar

Join Date: Apr 2012
Location: Melbs
Photos: Gallery | Albums
Posts: 1,148
It also explains why the 8mm on my Q doesn't leave the world looking like Predator vision.

11-07-2013, 04:09 PM   #36
Pentaxian
normhead's Avatar

Join Date: Jun 2007
Location: Near Algonquin Park
Photos: Gallery | Albums
Posts: 25,558
QuoteOriginally posted by Brew1brew Quote
there is noticeable CA on that Sigma, )
You're talking about a lens that costs $189. What I find amazing is how many top notch shots I have taken with it.
11-07-2013, 08:09 PM   #37
Senior Member




Join Date: Sep 2006
Location: Plano Texas USA
Posts: 121
QuoteOriginally posted by normhead Quote
You're talking about a lens that costs $189. What I find amazing is how many top notch shots I have taken with it.
Yes, I had an early version of it that I bought back in the film days. 70-300 DL macro if I remember right. It took some great shots with my *istD. As a matter of fact it's still with the *istD, gave it to my daughter and her husband (I'm trading them my GX1 for it, to get it back, when I get my K3). I did have to watch those bright light dark sharp edges though, lots of purple on it.
11-07-2013, 09:19 PM   #38
Site Supporter
jpzk's Avatar

Join Date: Jan 2009
Location: Québec
Photos: Gallery | Albums
Posts: 7,235
Original Poster
Thank you !

... to all who replied to this thread which I never expected would be so "popular"


In a nutshell: I have read all of the posts and decided to hold off any purchase for the moment.

So I will keep the K5/DA*300/4 and perhaps wait until a Pentax SDM 1.4X TC does show up .... this seems that it could be months, maybe years.

If I get too impatient, and when the finances allow it, it will be time to invest in a high quality lens in the 500mm range (prime .... likely to be a Siggy 500/4.5, again when budget permits it, and unless Ricoh-Pentax suddenly comes up with something appealing such as a high-grade 100-400 zoom lens .... who knows ?).

So, thanks again to everyone who took the time to reply .

Cheers!

JP

11-07-2013, 09:25 PM   #39
Veteran Member
stormtech's Avatar

Join Date: Jan 2011
Location: In the boonies (NW Penna)
Photos: Gallery | Albums
Posts: 5,670
QuoteOriginally posted by jpzk Quote
Thank you !

... to all who replied to this thread which I never expected would be so "popular"


In a nutshell: I have read all of the posts and decided to hold off any purchase for the moment.

So I will keep the K5/DA*300/4 and perhaps wait until a Pentax SDM 1.4X TC does show up .... this seems that it could be months, maybe years.

If I get too impatient, and when the finances allow it, it will be time to invest in a high quality lens in the 500mm range (prime .... likely to be a Siggy 500/4.5, again when budget permits it, and unless Ricoh-Pentax suddenly comes up with something appealing such as a high-grade 100-400 zoom lens .... who knows ?).

So, thanks again to everyone who took the time to reply .

Cheers!

JP
Glad you found some sense out of all that!

I'm in the same park JP - in a holding pattern. I, like you, would really benefit from the Sigma 500, but that just isn't possible. I am finally learning to work with what I have - and am finding that I kind of like that challenge anyway. New gear does not make better images!
Reply

Bookmarks
  • Submit Thread to Facebook Facebook
  • Submit Thread to Twitter Twitter
  • Submit Thread to Digg Digg
Tags - Make this thread easier to find by adding keywords to it!
crop, dslr, k-3, k3, k5, lens, pentax k-3
Thread Tools Search this Thread
Search this Thread:

Advanced Search


Similar Threads
Thread Thread Starter Forum Replies Last Post
What is the Shutter Count of the first image of a brand new K5? TropicalMonkey Pentax K-5 16 01-31-2013 01:45 AM
Should I Get the K5 IIs or Switch Systems? Hannican Pentax K-5 21 11-05-2012 11:13 AM
K7 - Upgrade to K30, buy a "cheap" K5 or Wait for the K3? EstimatedEyes Pentax K-30 & K-50 13 07-18-2012 04:14 PM
Travel The K5 is a big hit in Naples Fl charliezap Post Your Photos! 13 03-17-2012 07:30 PM
Keep K-x buy premium lens, get K-r and get good lens, get the K-7 w/ lens or K-5? crossover37 Pentax DSLR Discussion 19 02-06-2011 10:38 PM



All times are GMT -7. The time now is 02:21 AM. | See also: NikonForums.com, CanonForums.com part of our network of photo forums!
  • Red (Default)
  • Green
  • Gray
  • Dark
  • Dark Yellow
  • Dark Blue
  • Old Red
  • Old Green
  • Old Gray
  • Dial-Up Style
Hello! It's great to see you back on the forum! Have you considered joining the community?
register
Creating a FREE ACCOUNT takes under a minute, removes ads, and lets you post! [Dismiss]
Top