Focus issues.
Posted 03/07/2010 - 18:44
Link
Thoramay .. I think you need to do the focus chart again but get it square on. From the exif you also used the flash on the second shot but not the first. Take one shot on the tripod, no flash at the fastest aperture with the focus chart as square as possible.
Posted 03/07/2010 - 19:24
Link
Looks like it's front focusing with around 4mm but like the other says you need to get it square since that can influence the results.
Also if it's really critical you should do it outdoors since the AF works with light and the spectrum of artificial light is different and will effect auto focus although I don't it's that critical with your test set-up but if you focus at macro distance it might.
Also if it's really critical you should do it outdoors since the AF works with light and the spectrum of artificial light is different and will effect auto focus although I don't it's that critical with your test set-up but if you focus at macro distance it might.
Stefan
K10D, K5
DA* 16-50, DA* 50-135, D-FA 100 Macro, DA 40 Ltd, DA 18-55
AF-540FGZ
K10D, K5
DA* 16-50, DA* 50-135, D-FA 100 Macro, DA 40 Ltd, DA 18-55
AF-540FGZ
Posted 03/07/2010 - 19:49
Link
From the author of the test chart I believe is in use:
"It’s normal, particularly with longer focal lengths, to see the focused area, or depth of field, shifted slightly rearward, as in the pic on the right. This is not a problem as long as the focus line is still within the area that’s in focus."
(DoF is rarely equal either side of the focus point....)
http://focustestchart.com/chart.html
Place the test chart absolutely flat on a level surface. There must be no visible lumps or bumps in the chart. It needs to be flat.
Aim your camera at 45 degrees to the chart.
Focus on the centre of the focus line in the focus box at the centre of the chart.
When shooting your test pics, you need to be close enough that the test chart somewhat more than fills the frame. Get nice and close.
Ensure that you are not so close that the auto focus system is unable to focus due to you being at the limit of the range of focus of your lens.
You can check this by moving your camera closer and closer to the image and testing when it is no longer able to focus and then making sure that you are set up at least a few inches back from this point.
Set your camera to aperture priority mode (“A” on the rotary dial) and adjust the aperture setting as wide as it will go (lowest f-stop number) for the lens you have on the camera. This gives you the shallowest depth of field, which is crucial to this test.
Set the Autofocus system to “AF-S” mode (CSM Menu item 2).
Set the AF-area mode to “Single area” (CSM Menu item 3).
Ensure that you have the centre focus area selected. If not then adjust this using the multi selector button (up/down/left/right). The focus selector lock switch (just below the multi selector button) must be unlocked in order to change/select the appropriate focus area.
If you have extra lighting available, use it to light up the test chart. The chart must be lit more or less from the front. I like to use a bright constant light source, like a halogen flood or similar, but the flash seems to work just fine too. If you’re going to depend on the flash then make sure there’s enough ambient light for the auto focus system to work reliably.
Metering mode and centre weighting is not critical. As long as you’re getting a well lit, bright image out of the camera then it’s fine.
First shoot an initial pic and have a good look at it before you go further. Make sure the test chart is bright and white. Adjust your white balance and shutter speed to get this right. Use more light and/or the flash if necessary.
Use either the remote control (if you have one) or the camera’s self timer to trigger the shutter release in order to avoid any camera shake.
Just trying to help.
Best regards,
John
"It’s normal, particularly with longer focal lengths, to see the focused area, or depth of field, shifted slightly rearward, as in the pic on the right. This is not a problem as long as the focus line is still within the area that’s in focus."
(DoF is rarely equal either side of the focus point....)
http://focustestchart.com/chart.html
Place the test chart absolutely flat on a level surface. There must be no visible lumps or bumps in the chart. It needs to be flat.
Aim your camera at 45 degrees to the chart.
Focus on the centre of the focus line in the focus box at the centre of the chart.
When shooting your test pics, you need to be close enough that the test chart somewhat more than fills the frame. Get nice and close.
Ensure that you are not so close that the auto focus system is unable to focus due to you being at the limit of the range of focus of your lens.
You can check this by moving your camera closer and closer to the image and testing when it is no longer able to focus and then making sure that you are set up at least a few inches back from this point.
Set your camera to aperture priority mode (“A” on the rotary dial) and adjust the aperture setting as wide as it will go (lowest f-stop number) for the lens you have on the camera. This gives you the shallowest depth of field, which is crucial to this test.
Set the Autofocus system to “AF-S” mode (CSM Menu item 2).
Set the AF-area mode to “Single area” (CSM Menu item 3).
Ensure that you have the centre focus area selected. If not then adjust this using the multi selector button (up/down/left/right). The focus selector lock switch (just below the multi selector button) must be unlocked in order to change/select the appropriate focus area.
If you have extra lighting available, use it to light up the test chart. The chart must be lit more or less from the front. I like to use a bright constant light source, like a halogen flood or similar, but the flash seems to work just fine too. If you’re going to depend on the flash then make sure there’s enough ambient light for the auto focus system to work reliably.
Metering mode and centre weighting is not critical. As long as you’re getting a well lit, bright image out of the camera then it’s fine.
First shoot an initial pic and have a good look at it before you go further. Make sure the test chart is bright and white. Adjust your white balance and shutter speed to get this right. Use more light and/or the flash if necessary.
Use either the remote control (if you have one) or the camera’s self timer to trigger the shutter release in order to avoid any camera shake.
Just trying to help.
Best regards,
John
Posted 03/07/2010 - 21:36
Link
What is the lowest F stop number? I used F4. is that wrong?. I have read all of the instructions carefully but it is not for a Pentax.
It did mention flash and I tried it on the second shot but then realised I had it on two second delay and the flash was over before the camera fired and would have had no effect
You will need to hold my hand in this.
Tomorrrow I will take it outdoors in my greenhouse set up for macro work.
Maximum aperature F32? or F2.8?
Get it square on
Set on AV. 2 second timer on
On tripod. Camera set at 45%
It did mention flash and I tried it on the second shot but then realised I had it on two second delay and the flash was over before the camera fired and would have had no effect
You will need to hold my hand in this.
Tomorrrow I will take it outdoors in my greenhouse set up for macro work.
Maximum aperature F32? or F2.8?
Get it square on
Set on AV. 2 second timer on
On tripod. Camera set at 45%
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1568 posts
18 years
Rainhill
Regards,
John
In LBA hiatus.