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03-15-2011, 04:05 AM   #91
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QuoteOriginally posted by Ray Pulley Quote
I have a K5 due this week, which gives me a trifecta of: K20, K7, K5 to compare.
Cool, shall be very interesting to see these compared in the same conditions.

Your setup sounds very good, so I'm looking forward to seeing your results (K-5 on its own and/or compared to K-7/K20D).

03-15-2011, 07:14 AM - 1 Like   #92
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QuoteOriginally posted by Nico13 Quote
My sentiments also very poorly aligned charts.
Throw this test out and start again with everything properly aligned and you may get some meaningful results.
Hi there

The slight misalignment of the chart was nowhere near enough to render the result of the tests a failure. The amount the K-5 is front focussing is far greater than any slight chartr misalignment
03-15-2011, 12:58 PM   #93
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QuoteOriginally posted by Tommot1965 Quote
I wonder why that is..Mines the same..perfect from about 35mm on, i tested my 70-200 Sigma last night. that was perfect too...it seems the wider you go the worse it is..
It IS weird, at 17mm the lens has a 2.8 aperture but at 70mm it's 4.5. So even though the lens lets in less light at 70mm it focuses a lot better.
03-15-2011, 01:55 PM   #94
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QuoteOriginally posted by Gimbal Quote
It IS weird, at 17mm the lens has a 2.8 aperture but at 70mm it's 4.5. So even though the lens lets in less light at 70mm it focuses a lot better.
it may be because at F4.5 your getting greater DOF ?.....

my 17-50 is a constant aperture , so the greater DOF doesn't hold up for that particular lens

03-15-2011, 02:11 PM   #95
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QuoteOriginally posted by Tommot1965 Quote
it may be because at F4.5 your getting greater DOF ?.....
No not in this case, the distance scale on the focus ring shows what happens. When using LV the focus ring indicates 2m to object (for instance) both at 17 and 70mm.

When using PF the distance ring still indicates 2m at 70mm, but incorrectly settles at (roughly) 1m at 17mm focal length. So the lens is set very wrong at 17mm focal length no matter what the DOF is.
03-15-2011, 02:11 PM   #96
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Well I've spoken to my dealer now. K-5 is being replaced next week fingers crossed.
03-15-2011, 02:26 PM   #97
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Is the SpyderLensCal thing worth buying?
03-15-2011, 05:07 PM   #98
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QuoteOriginally posted by Fl_Gulfer Quote
Is the SpyderLensCal thing worth buying?
In my opinion it isn't, since you can pretty easily recreate the functionality offered by a little DIY.

The LensAlign tool is a bit of a different story because it offers alignment aids. Nothing that cannot be achieved by some DIY effort either, but at least there is a bit more functionality.

I don't think either of them are ideal because of the distance between focus target and measuring spot (-> field curvature). They will allow calibration with some accuracy but so will a print of a free test chart.

Both tools are interesting for those with more money than time.

If you want to be a 100% about this, align the camera parallel to some flat target (e.g., by using a mirror) and then do AF adjustment bracketing. More details can be found in my AF adjustment hints.

03-16-2011, 04:43 PM   #99
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QuoteOriginally posted by Tommot1965 Quote
I wonder why that is..Mines the same..perfect from about 35mm on, i tested my 70-200 Sigma last night. that was perfect too...it seems the wider you go the worse it is.. but at least I know that..so I stay away from the wide end of my sigma 17-50 if in low light. if Im close 300mm away..even at 17 mm its ok...seem the further you get from the focal plane the worse it is too...very strange so even though mines not good at very wide FL...Im considering it good enough for my needs..perhaps future FW fix will sort it for us
This sounds interesting. I wonder if it could be explored further?
03-16-2011, 11:01 PM   #100
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QuoteOriginally posted by Class A Quote
Cool, shall be very interesting to see these compared in the same conditions.

Your setup sounds very good, so I'm looking forward to seeing your results (K-5 on its own and/or compared to K-7/K20D).
The K5 was here when I got home this evening, so I ran a few tests. I do not have time tonight to post K20 and K5 comparisons, but I can post some shots that show the firmware 1.01 performance in low light versus the 1.03 in the same light.

Here is the setup:

K5
FA 50 f1.4
LensAlign target on a tripod with a leveling bubble attached to the mounting plate. Note that this target has a provision for making sure that the sensor is parallel to the target.
K5 on a very sturdy tripod with a leveling bubble built into my Manfroto grip.
Lighting - 2 300ws studio strobes with 250w halogen modeling lights that are dimmable.
Sekonic L-358 handheld meter set to read in EV. Readings taken at target face.
Gossen Color meter 3F. Readings taken at target face.
Camera set to remote trigger with 3 second delay.
Lens reset to infinty between each shot.
AF assist never came on but focusing was slow and it hunted a bit at EV2.

EV was 2, color temp was just above the meter minimum at 2040K.



Some notes:

I have tested the setup with my 5500K CFL lights and it does move to BF a bit but it holds DOF. Note that my earlier tests with these lights against daylight show that they BF more than natural noon sunlight. I suspect that they are more blue than normal sunlight. I will confirm in sunlight as soon as the sun comes back out and I have a bit of time.

I shot a couple of quick tests of my lovely wife in very dim indoor conditions where I could not get the K5 to hold DOF using earlier firmware. The results looked good.

It SPANKS my K20, which will not hold DOF below f4.0 with this exact setup (and barely at that). I will post those shots a bit later along with K7 tests as well for comparison.

I noticed some very odd behavior after setting the initial AF adjust:

The camera varied all over the place at various apertures, showing BF at one aperture and FF the next. I reset the camera to UNSET and re-shot the sequence, and things were very consistent, but BF. I then dialed in the AF adjust again (+2)and re-shot and the results were much better. It still moves around a bit from some BF to some FF, but it holds DOF at all of the apertures I tested (1.4 through 5.6). I would suggest that anyone who sees inconsistent AF or no change after the firmware update try unsetting and resetting the AF adjust. I have no other explanation for what I saw.

Of course, the odd bevaior may come back as I do not yet have extensive time with the camera.

Some real shooting is needed to confirm results in daylight and under my normal shooting conditions, but at this point, I think it is a keeper.

Ray
03-16-2011, 11:57 PM   #101
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nice one Ray..great test mate..

any chance you could test a wider FL..say 16-17 FL...at 2.8
03-17-2011, 12:43 AM   #102
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QuoteOriginally posted by Ray Pulley Quote
The camera varied all over the place at various apertures, showing BF at one aperture and FF the next. I reset the camera to UNSET and re-shot the sequence, and things were very consistent, but BF. I then dialed in the AF adjust again (+2)and re-shot and the results were much better. It still moves around a bit from some BF to some FF, but it holds DOF at all of the apertures I tested (1.4 through 5.6). I would suggest that anyone who sees inconsistent AF or no change after the firmware update try unsetting and resetting the AF adjust. I have no other explanation for what I saw.

The performance of the 1.03 seems to be very inconsistent. At first I thought it was a big improvement, a couple of days later I'm not so sure. It still seems to front focus a lot in real usage.
03-17-2011, 01:48 AM   #103
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Great test, Ray, thanks!

QuoteOriginally posted by Ray Pulley Quote
It still moves around a bit from some BF to some FF, but it holds DOF at all of the apertures I tested (1.4 through 5.6).
That is a bit disconcerting but I wonder if the FA 50/1.4 plays a part in this. It is one of the few lenses my K100D often hesitates to lock correct focus.

Was it really problem free without AF adjustments? If we can confirm a difference in behaviour regarding AF adjustments vs no adjustments that would very much point to a bug to me (as long as the adjustments are moderate).
03-17-2011, 01:52 AM   #104
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QuoteOriginally posted by Gimbal Quote
When using PF the distance ring still indicates 2m at 70mm, but incorrectly settles at (roughly) 1m at 17mm focal length. So the lens is set very wrong at 17mm focal length no matter what the DOF is.
Are you sure that the AF area still only sees the focus target? If you go too wide, the AF area might include part of the measurement "rulers".
03-17-2011, 03:00 AM   #105
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QuoteOriginally posted by Class A Quote
Are you sure that the AF area still only sees the focus target? If you go too wide, the AF area might include part of the measurement "rulers".
Yes, as the error is so large that I simple aim at a flat wall (specifically the frame of a painting which should give lots of contrast against the wall for PF to lock on).

Also, (a habit from the k10d) if there is time I always engage the AF several times, slightly changing my aim just to make sure that there isn't a hidden problem in the area for the AF.
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