Thoughts on these focus tests?

sebberry · 08-03-2009, 03:31 PM

Not seeing perfect results here. It all sort of started when I noticed that the wrong part of a person's face was in focus when I was using the FA 50mm.

Pics taken on a tripod using the two second timer and the AF540 bounced off the ceiling. SR off.

Thanks for looking and letting me know what you think

1)DA 18-55, 18mm@4.5:

2)DA 18-55, 18mm@5.6:

3) DA 50-200, 50mm@5.6:

4) FA50 1.4, 50mm @1.4:

5) FA50 1.4, 50mm @2.8:

5) FA50 1.4, 50mm @5.6:

flyer · 08-03-2009, 04:46 PM

Can't say much. Your first two pictures don't seem to be square to the target, so, starting from there, it is possible to question the rigor of your testing. As for the 50 mm. lens, it seems soft wide open, but it seems to improve as you stop down. I'm still skeptical about the validity of your test. Maybe you should go to "Yvon Bourque's blog" and dowload his test target. I think it is more accurate than the one you are using.

inferno10 · 08-03-2009, 08:40 PM

May I suggest that you use this focus chart instead? It has more gradations, so it's easier to differentiate between sharp and soft.

http://regex.info/i/FocusChart-v1.0-gray10.gif

- Jason

Daveinozbikes · 08-04-2009, 03:16 AM

Good chart Jason...thanks mate !!!

flyer · 08-04-2009, 04:04 AM

Originally posted by inferno10

May I suggest that you use this focus chart instead? It has more gradations, so it's easier to differentiate between sharp and soft.

http://regex.info/i/FocusChart-v1.0-gray10.gif

- Jason

There is too much "crap" on that focus chart. You can never be sure where your focus sensor locked focus. Look at the chart on Yvon Bourque's blog. The way it's designed, you know exactly what your focusing sensor locked on.

**ManuH** · 08-04-2009, 08:20 AM

Originally posted by inferno10

May I suggest that you use this focus chart instead? It has more gradations, so it's easier to differentiate between sharp and soft.

http://regex.info/i/FocusChart-v1.0-gray10.gif

- Jason

You should link the explanation page because there are many different versions of this chart with various level of grays. You have first to make sure that the camera cannot lock on to the grey parts.

Parallax · 08-04-2009, 10:47 AM

I use a chart mounted on cardboard that pivots on a rod. The chart is turned so that it is parallel to the sensor for focusing then turned 45 degrees for exposure. That way there where is no question where the camera focused

08-03-2009, 03:31 PM	#1
sebberry Pentaxian Join Date: Jan 2009 Location: Frozen white North Photos: Albums Posts: 1,135	Thoughts on these focus tests? Not seeing perfect results here. It all sort of started when I noticed that the wrong part of a person's face was in focus when I was using the FA 50mm. Pics taken on a tripod using the two second timer and the AF540 bounced off the ceiling. SR off. Thanks for looking and letting me know what you think 1)DA 18-55, 18mm@4.5: 2)DA 18-55, 18mm@5.6: 3) DA 50-200, 50mm@5.6: 4) FA50 1.4, 50mm @1.4: 5) FA50 1.4, 50mm @2.8: 5) FA50 1.4, 50mm @5.6:

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08-03-2009, 04:46 PM	#2
flyer Veteran Member Join Date: Jan 2008 Location: Ste-Anne des Plaines, Qc., Canada Posts: 2,013	Can't say much. Your first two pictures don't seem to be square to the target, so, starting from there, it is possible to question the rigor of your testing. As for the 50 mm. lens, it seems soft wide open, but it seems to improve as you stop down. I'm still skeptical about the validity of your test. Maybe you should go to "Yvon Bourque's blog" and dowload his test target. I think it is more accurate than the one you are using.

08-03-2009, 08:40 PM	#3
inferno10 Veteran Member Join Date: Feb 2007 Location: San Francisco, California Posts: 342	May I suggest that you use this focus chart instead? It has more gradations, so it's easier to differentiate between sharp and soft. http://regex.info/i/FocusChart-v1.0-gray10.gif - Jason

08-04-2009, 03:16 AM	#4
Daveinozbikes Senior Member Join Date: Dec 2008 Location: Dawesville,Western Australia. Photos: Gallery Posts: 128	Good chart Jason...thanks mate !!!

08-04-2009, 04:04 AM	#5
flyer Veteran Member Join Date: Jan 2008 Location: Ste-Anne des Plaines, Qc., Canada Posts: 2,013	Originally posted by inferno10 May I suggest that you use this focus chart instead? It has more gradations, so it's easier to differentiate between sharp and soft. http://regex.info/i/FocusChart-v1.0-gray10.gif - Jason There is too much "crap" on that focus chart. You can never be sure where your focus sensor locked focus. Look at the chart on Yvon Bourque's blog. The way it's designed, you know exactly what your focusing sensor locked on.

08-04-2009, 08:20 AM	#6
ManuH Site Supporter Join Date: Dec 2007 Location: Montreal Photos: Gallery \| Albums Posts: 1,249	Originally posted by inferno10 May I suggest that you use this focus chart instead? It has more gradations, so it's easier to differentiate between sharp and soft. http://regex.info/i/FocusChart-v1.0-gray10.gif - Jason You should link the explanation page because there are many different versions of this chart with various level of grays. You have first to make sure that the camera cannot lock on to the grey parts.

08-04-2009, 10:47 AM	#7
Parallax Senior Moderator Loyal Site Supporter Join Date: Apr 2008 Location: South Dakota Photos: Gallery Posts: 19,332	I use a chart mounted on cardboard that pivots on a rod. The chart is turned so that it is parallel to the sensor for focusing then turned 45 degrees for exposure. That way there where is no question where the camera focused

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