Magazine Review: K20D/SDM AF.C performance vs. 8 competitors (Good Info!)

falconeye · 04-28-2008, 04:23 AM

Originally posted by ogl

K20D made 3 fps*3.6 sec*6 series = 65 images, 5.8 is absolute number of in-focus shots , it's 8.9%. [...] And this test has the odour of PR of A700

Hi ogl, you mixed things up here...

The total number of shots of K20D are:

6 * 5.8 * 100 / (100 - 25.6) = 47 (must be an integer number )

Therefore, total number of out-of-focus shots is 12 and in-focus 35. Divide by 6 (# series) and you get the figures.

They probably had 5 series with (6+2) and 1 series with (5+2) shots (in-focus + out-of-focus).

Same for your other figures, i.e., wrong.

The test is certainly not Sony PR. It's not even (yet) on Sony.de website... Germany used to be less marketing-driven than other countries and still is. Facts rule.

thibs · 04-28-2008, 06:22 AM

Originally posted by Jonson PL

For K100 and *Ist users, there'll be the SDM rear converter, so they can use SDM lenses.

No I don't think so, the SDM converter is just a teleconverter which is SDM enabled and nothing else. I really do not think Pentax will ever produce a teleconverter allowing SDM-only lenses to work on no-SDM bodies. It just won't happen, it would require to embed a full SDM AF subsystem into the converter. No way.

ogl · 04-28-2008, 06:24 AM

total number of shots of K20 = 6 series*3.6 sec each - 3 fps*3.6 = 10.8.
10.8*6 = 65.

Time to drive through 100m: 3.6s. Right?
The Starting photo burst at 100m distance. Right?
The speed of K20D is 3 fps. Right?
K20D tooks for 1 serie ~ 11 images. Right?

falconeye · 04-28-2008, 06:35 AM

Originally posted by ogl

Why total number of shots of K20 = 6 series*3.6 sec each - 3 fps*3.6 = 10.8.
10.8*6 = 65.

ogl, just trust my post and calculus. I cannot help you more than I already did in my previous post -- maybe one point though... 3fps is your speculation and is wrong, of course, as no camera shoots at peak rate when doing AF in between. So, why speculate it were 65 images when we can compute that it were 47 images exactly?

mattdm · 04-28-2008, 07:28 AM

Originally posted by thibs

No I don't think so, the SDM converter is just a teleconverter which is SDM enabled and nothing else. I really do not think Pentax will ever produce a teleconverter allowing SDM-only lenses to work on no-SDM bodies. It just won't happen, it would require to embed a full SDM AF subsystem into the converter. No way.

Not necessarily. The SDM AF subsystem is already in each lens, after all. The problem is communication. One possible way this could work is for the SDM converter to connect to the AF drive shaft on the camera side and have the SDM electronic contacts on the other side. When it detects the camera trying to focus the lens, it'd send the "okay, do your stuff" message out the other side.

I'm not exactly sure what advantage this'd really have, but there's one way to do it.

Oh, wait — the other problem would be power. Not sure any of the KAF contacts could be used to provide enough energy to power the SDM.

And, the next problem is: how is the thickness of this converter going to be corrected for? It'd have to also be a teleconverter, wouldn't it?

thibs · 04-29-2008, 08:17 AM

Indeed, I think that converter would need a couple batteries in it for power

Let's say we should forget about it

ogl · 05-09-2008, 06:04 AM

Answer from Photo-Magazine.

Fazit
Bei der absoluten Anzahl
korrekt fokussierter Aufnahmen liegt die Highspeed-Profi-SLR
EOS-1D Mark 3 mit Abstand an der Spitze,gefolgt von der Nikon D3 und der EOS 40D. Prozentual weichen die Ergebnisse weniger stark voneinander ab: Mit Ausnahme der Pentax K200 liegen hier alle Kameras mit jeweils optimalen AF-Modus ueber 80 Prozent.

K200????

No problem to call and ask
fotoMagazin | Redaktion

04-28-2008, 06:24 AM	#138
ogl Banned Join Date: Dec 2007 Location: Sankt Peterburg Photos: Gallery \| Albums Posts: 8,382	total number of shots of K20 = 6 series3.6 sec each - 3 fps3.6 = 10.8. 10.86 = 65. Time to drive through 100m: 3.6s. Right? The Starting photo burst at 100m distance. Right? The speed of K20D is 3 fps. Right? K20D tooks for 1 serie ~ 11 images. Right? Last edited by ogl; 04-28-2008 at 07:49 AM.*

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
Is there any info about PENTAX-DA 1.4X REAR CONVERTER SDM?	ogl	Pentax News and Rumors	18	10-01-2009 06:17 AM
K-7 receives top ratings in Swedish magazine review	ktwse	Pentax DSLR Discussion	13	08-17-2009 04:57 PM
AF problems - Pentax K20D vs S**y A 350 review - Amateur Photogr'y Magazine 17.5.2008	Confused	Pentax DSLR Discussion	71	07-05-2008 02:43 PM
Digital Camera Magazine K20D review	rparmar	Pentax DSLR Discussion	8	04-28-2008 05:14 AM
HDR Question ?....K20D Review - What Digital Camera magazine May 2008 (Issue 135)	Confused	Pentax DSLR Discussion	2	04-25-2008 06:44 PM

04-28-2008, 04:23 AM	#136
falconeye Veteran Member Join Date: Jan 2008 Location: Munich, Alps, Germany Photos: Gallery Posts: 6,871 Original Poster	Originally posted by ogl K20D made 3 fps3.6 sec6 series = 65 images, 5.8 is absolute number of in-focus shots , it's 8.9%. [...] And this test has the odour of PR of A700 Hi ogl, you mixed things up here... The total number of shots of K20D are: 6 * 5.8 * 100 / (100 - 25.6) = 47 (must be an integer number ) Therefore, total number of out-of-focus shots is 12 and in-focus 35. Divide by 6 (# series) and you get the figures. They probably had 5 series with (6+2) and 1 series with (5+2) shots (in-focus + out-of-focus). Same for your other figures, i.e., wrong. The test is certainly not Sony PR. It's not even (yet) on Sony.de website... Germany used to be less marketing-driven than other countries and still is. Facts rule.

04-28-2008, 06:22 AM	#137
thibs Pentaxian Join Date: Jun 2007 Location: Belgium Photos: Albums Posts: 7,001	Originally posted by Jonson PL For K100 and *Ist users, there'll be the SDM rear converter, so they can use SDM lenses. No I don't think so, the SDM converter is just a teleconverter which is SDM enabled and nothing else. I really do not think Pentax will ever produce a teleconverter allowing SDM-only lenses to work on no-SDM bodies. It just won't happen, it would require to embed a full SDM AF subsystem into the converter. No way.

04-28-2008, 06:35 AM	#139
falconeye Veteran Member Join Date: Jan 2008 Location: Munich, Alps, Germany Photos: Gallery Posts: 6,871 Original Poster	Originally posted by ogl Why total number of shots of K20 = 6 series3.6 sec each - 3 fps3.6 = 10.8. 10.86 = 65. ogl, just trust my post and calculus. I cannot help you more than I already did in my previous post -- maybe one point though... 3fps is your speculation and is wrong, of course, as no camera shoots at peak rate when doing AF in between. So, why speculate* it were 65 images when we can compute that it were 47 images exactly?

04-28-2008, 07:28 AM	#140
mattdm Veteran Member Join Date: Feb 2007 Location: Boston, MA Photos: Gallery Posts: 2,948	Originally posted by thibs No I don't think so, the SDM converter is just a teleconverter which is SDM enabled and nothing else. I really do not think Pentax will ever produce a teleconverter allowing SDM-only lenses to work on no-SDM bodies. It just won't happen, it would require to embed a full SDM AF subsystem into the converter. No way. Not necessarily. The SDM AF subsystem is already in each lens, after all. The problem is communication. One possible way this could work is for the SDM converter to connect to the AF drive shaft on the camera side and have the SDM electronic contacts on the other side. When it detects the camera trying to focus the lens, it'd send the "okay, do your stuff" message out the other side. I'm not exactly sure what advantage this'd really have, but there's one way to do it. Oh, wait — the other problem would be power. Not sure any of the KAF contacts could be used to provide enough energy to power the SDM. And, the next problem is: how is the thickness of this converter going to be corrected for? It'd have to also be a teleconverter, wouldn't it?

04-29-2008, 08:17 AM	#141
thibs Pentaxian Join Date: Jun 2007 Location: Belgium Photos: Albums Posts: 7,001	Indeed, I think that converter would need a couple batteries in it for power Let's say we should forget about it

05-09-2008, 06:04 AM	#142
ogl Banned Join Date: Dec 2007 Location: Sankt Peterburg Photos: Gallery \| Albums Posts: 8,382	Answer from Photo-Magazine. Fazit Bei der absoluten Anzahl korrekt fokussierter Aufnahmen liegt die Highspeed-Profi-SLR EOS-1D Mark 3 mit Abstand an der Spitze,gefolgt von der Nikon D3 und der EOS 40D. Prozentual weichen die Ergebnisse weniger stark voneinander ab: Mit Ausnahme der Pentax K200 liegen hier alle Kameras mit jeweils optimalen AF-Modus ueber 80 Prozent. K200???? No problem to call and ask fotoMagazin \| Redaktion