Buy the K3, crop the image or get a longer FL lens - keep the K5 ?

tromboads · 11-07-2013, 01:59 PM

Originally posted by Andi Lo

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

Brew1brew · 11-07-2013, 02:23 PM

Originally posted by normhead

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?)

Dr_who · 11-07-2013, 02:25 PM

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.

Andi Lo · 11-07-2013, 03:17 PM

Originally posted by tromboads

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

tromboads · 11-07-2013, 04:01 PM

It also explains why the 8mm on my Q doesn't leave the world looking like Predator vision.

normhead · 11-07-2013, 04:09 PM

Originally posted by Brew1brew

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.

Brew1brew · 11-07-2013, 08:09 PM

Originally posted by normhead

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.

**jpzk** · 11-07-2013, 09:19 PM

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

stormtech · 11-07-2013, 09:25 PM

Originally posted by jpzk

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!

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11-07-2013, 01:59 PM	#31
tromboads Veteran Member Join Date: Apr 2012 Location: Melbs Photos: Gallery Posts: 1,240	Originally posted by Andi Lo 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
Brew1brew Senior Member Join Date: Sep 2006 Location: Plano Texas USA Posts: 121	Originally posted by normhead 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
Dr_who Veteran Member Join Date: Jun 2009 Location: Edmonton, Alberta, Canada Photos: Gallery \| Albums Posts: 777	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
Andi Lo Veteran Member Join Date: Jul 2008 Location: Halifax, Nova Scotia Posts: 2,924	Originally posted by tromboads 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
tromboads Veteran Member Join Date: Apr 2012 Location: Melbs Photos: Gallery Posts: 1,240	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
normhead Pentaxian Join Date: Jun 2007 Location: Near Algonquin Park Photos: Gallery \| Albums Posts: 40,451	Originally posted by Brew1brew 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
Brew1brew Senior Member Join Date: Sep 2006 Location: Plano Texas USA Posts: 121	Originally posted by normhead 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
jpzk Site Supporter Join Date: Jan 2009 Location: Québec Photos: Gallery \| Albums Posts: 8,251 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
stormtech Veteran Member Join Date: Jan 2011 Location: In the boonies (NW Penna) Photos: Gallery \| Albums Posts: 5,744	Originally posted by jpzk 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!