[GordonZA]

Rice high has posted links to some folk that have been out shooting with the 560mm, the FA*250-600 and another lens... Have a look at his blog...

Some very nice results of small birds in park.. With field comparisons...

[Asahiflex]

If you want it desperately, there is one on sale in Italy. 6000 euros like new. Pentaxiani • Leggi argomento - (VA+sp) Pentax F* 250-600 + tutti gli A* e FA*

That's my old F* 250-600 I sold to him! I hope it will end in the hands of a fellow Pentaxian

[borno]

If you shoot large birds like cranes and herons OK, but if you shoot lilttle passerines you need to stop down at least to F/8 to have eyes and shoulders included in the dof. Sometimes shallow depth of field is worse on the output than high ISO. IMO.

I would still want sharp wide open with no CA (and a ring AF motor) and useable with a TC, or why spend that much. ?? Good service is important to me also, if you ever need it, and if you use your stuff a lot, you will eventually.

[goubejp]

If you shoot large birds like cranes and herons OK, but if you shoot lilttle passerines you need to stop down at least to F/8 to have eyes and shoulders included in the dof. Sometimes shallow depth of field is worse on the output than high ISO. IMO.

Right, at 10 meters a 600 at f4 has only 4 cms of depths of field; most of the time I stop my 600 to f8 to get 8 cms of depths of field to get managable depth of field

[miles]

That's my old F* 250-600 I sold to him! I hope it will end in the hands of a fellow Pentaxian

Oh my, i might actually get it!!!!
I feel like i'm about to jump off a plane (with some parachute of some sort)!

[borno]

Right, at 10 meters a 600 at f4 has only 4 cms of depths of field; most of the time I stop my 600 to f8 to get 8 cms of depths of field to get managable depth of field

I like a little blur sometimes (300mm at f2.8)

[falconeye]

No birds for you yet, but feel free to pixel peep these test charts (center):

F5.6 / 8 / 11 (center)
https://themotec1.netfirms.com/Users/Hosted/cdn/DA560/DA560-A-ctr-F056_130226_22s_w.tif
https://themotec1.netfirms.com/Users/Hosted/cdn/DA560/DA560-A-ctr-F080_130226_23s_w.tif
https://themotec1.netfirms.com/Users/Hosted/cdn/DA560/DA560-A-ctr-F110_130226_24s_w.tif

F* 250-600mm at F5.6, for comparison, center:
https://themotec1.netfirms.com/Users/Hosted/cdn/DA560/F520-A-ctr-F056_130226_80s_w.tif

Adam, thanks for doing this.

I am a bit confused about visible "print-like" texture in uniform black areas and no moiré showing up at Nyquist (it really should with the K-5IIs, it always does with my D800E having the same pixel pitch). So, I measured some MTF figures with hesitation. But here we go:

CA was about the same for both lenses and didn't really change with aperture. It was about 1.2px near the APS-C corners (70% from center) and 0.7px near the center (10% from center). Near the center, CA went down to 0.3px when stopping down.

Resolution in lp/mm (at 10% / 70% from center):
DA560 @F5.6: 22/19 line pairs per mm
DA560 @F8: 24/24 line pairs per mm
DA560 @F11: 26/26 line pairs per mm
FA520 @F5.6: 25/21 line pairs per mm

Note that the TIFF files are unsharpened output probably. The 10-90% edge rise width is pretty large (4,7px for the first figure of 22 lp/mm). But that's normal for unsharpened values. The corner sharpness was measured in the upper left und lower right corners with one of two orientations, and then averaged.

In order to calibrate the process and better judge the meaning of values, a similiar example of a K-5IIs with the DA70 at its sweet spot of F4.0 would be welcome.

From numbers alone, I would say that both, FA200-500 and DA560 are a bit on the weak side of things. 30 lp/mm curves should normally stay well above 50%. But it is easy to introduce blur in tele lens tests, quality of focus being one of them. The fact that center resolution improves when going from F8 to F11 (it really shouldn't for all but a lemon) is a hint in this direction. The total lack of Bayer moiré is another.

---

Last edited by falconeye; 03-05-2013 at 10:00 AM.

[goubejp]

I like a little blur sometimes (300mm at f2.8)

Nice shot; wouldn't have been better with deeper depth of field? You have use it as a portraiture lens indeed

[falconeye]

Not entirely on topic but worth a mention:

Nikon has updated the 80-400/4.5-5.6 and the new MTF figures look much more interesting -> Nikon | Imaging Products | AF-S NIKKOR 80-400mm f/4.5-5.6G ED VR

The 30 lp/mm MTF at the tele end stays above 65-85% (old version in the middle, reputed Canon 100-400/4.5-5.6L to the right):



Depending on what we find for the DA560, it may be another possible competitor, esp. if combined with an 1.4xTC which does still AF.

[Ole]

Ii was actually I who was "volunteered" to do those DA560 tests and I have refrained form calculating any resolution numbers for the reasons you point out.

Obtaining 100% accurate focus is an impossibility by manual focusing a K-5 IIs so I resorted to relying on CDAF. So that's what you got and perhaps that's why F11 may look sharper than F8?

Eliminating any and all vibrations during the shot was very hard with this long bastard of a lens. If someone donates a much studier tripod than the one I've got (Manfrotto 458B) I'll reshoot The F*250-600 actually was more stable on the tripod (it also weighs more).

I was also baffled by the lack of moire, I can only chalk it down to lack of resolution due to either inaccurate focus of vibrations.

Adam, thanks for doing this.

I am a bit confused about visible "print-like" texture in uniform black areas and no moiré showing up at Nyquist (it really should with the K-5IIs, it always does with my D800E having the same pixel pitch). So, I measured some MTF figures with hesitation. But here we go:

CA was about the same for both lenses and didn't really change with aperture. It was about 1.2px near the APS-C corners (70% from center) and 0.7px near the center (10% from center). Near the center, CA went down to 0.3px when stopping down.

Resolution in lp/mm (at 10% / 70% from center):
DA560 @F5.6: 22/19 line pairs per mm
DA560 @F8: 24/24 line pairs per mm
DA560 @F11: 26/26 line pairs per mm
FA520 @F5.6: 25/21 line pairs per mm

Note that the TIFF files are unsharpened output probably. The 10-90% edge rise width is pretty large (4,7px for the first figure of 22 lp/mm). But that's normal for unsharpened values. The corner sharpness was measured in the upper left und lower right corners with one of two orientations, and then averaged.

In order to calibrate the process and better judge the meaning of values, a similiar example of a K-5IIs with the DA70 at its sweet spot of F4.0 would be welcome.

From numbers alone, I would say that both, FA200-500 and DA560 are a bit on the weak side of things. 30 lp/mm curves should normally stay well above 50%. But it is easy to introduce blur in tele lens tests, quality of focus being one of them. The fact that center resolution improves when going from F8 to F11 (it really shouldn't for all but a lemon) is a hint in this direction. The total lack of Bayer moiré is another.

[ElJamoquio]

Eliminating any and all vibrations during the shot was very hard with this long bastard of a lens. If someone donates a much studier tripod than the one I've got (Manfrotto 458B) I'll reshoot

How long will you have the lenses?

[traderdrew]

I have never seen a series of controlled tests for the Sigma 500mm F/4.5. Has anybody found some on the net? I have seen a report that it is sharpest around F/7.1 to F/8. I have this lens and I think highly of it. It seems to me that it can outperform the resolution of the K-5 when I nail some of my subjects.

[froeschle]

F(A)* 250-600:

The Lens Design of SMC PENTAX F* 250-600

MTF, Position2

[Ole]

How long will you have the lenses?

The DA560: Through March 23.

The F*250-600: Forever, it is Adam's.

[gazonk]

Obtaining 100% accurate focus is an impossibility by manual focusing a K-5 IIs so I resorted to relying on CDAF.

Isn't manual focus @ 10x in LV more reliable than CDAF?