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Messages - AlanF

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16
Lenses / Re: Tamron 150-600mm AF servo issues?
« on: March 29, 2014, 07:29:59 AM »
I am looking out of the window on the 17th floor of a Shanghai hotel, with the cityscape shrouded in mist and evening coming in at 5-15 pm. There is virtually no contrast between the grey spikes on top of the buildings and the grey mist. So, nothing better to do I have tested A1 servo on the 5DIII and the Tamron.

1. Set to centre spot focus, A1 servo and 600mm, the lens locks on very quickly to a very thin pole on the top of a distant building and instantly refocusses as I pan to closer and closer objects and back again. So absolutely no problem.

2. Set to the 9 centre points focus, A1 servo and 600mm, the lens locks on much more slowly to that very thin pole.

3. Set to all points focus, A1 servo and 600mm, the lens locks on even more slowly to that very thin pole and struggles to refocus. So, there is a problem with this setting in these extreme conditions.

But, I recall that with the 300mm f/2.8 + 2xTC @600mm, I have been sometimes been disappointed with the 9 centre points focussing. So, there could be problems under certain conditions when tracking with all points, but this is probably not unique to the Tamron.

I fly back in to shanghai tomorrow, want to grab a beer?

We will be in Pudong tomorrow night before leaving on Monday morning for Guilin for a week. Where will you be?

17
Lenses / Re: Tamron 150-600mm AF servo issues?
« on: March 29, 2014, 06:27:25 AM »
1. Set to centre spot focus, A1 servo and 600mm, the lens locks on very quickly to a very thin pole on the top of a distant building and instantly refocusses as I pan to closer and closer objects and back again. So absolutely no problem.

Does it still work if you move quickly to a much closer object and back again?

That's where I have problems - if the change in focus distance is small it will re-focus both closer and farther away.
If the change in focus distance is large, then it will only refocus to a closer object.

Phil.
Yes - I tested that as you had reported a problem. It was fine.

18
Lenses / Re: Tamron 150-600mm AF servo issues?
« on: March 29, 2014, 05:39:25 AM »
I am looking out of the window on the 17th floor of a Shanghai hotel, with the cityscape shrouded in mist and evening coming in at 5-15 pm. There is virtually no contrast between the grey spikes on top of the buildings and the grey mist. So, nothing better to do I have tested A1 servo on the 5DIII and the Tamron.

1. Set to centre spot focus, A1 servo and 600mm, the lens locks on very quickly to a very thin pole on the top of a distant building and instantly refocusses as I pan to closer and closer objects and back again. So absolutely no problem.

2. Set to the 9 centre points focus, A1 servo and 600mm, the lens locks on much more slowly to that very thin pole.

3. Set to all points focus, A1 servo and 600mm, the lens locks on even more slowly to that very thin pole and struggles to refocus. So, there is a problem with this setting in these extreme conditions.

But, I recall that with the 300mm f/2.8 + 2xTC @600mm, I have been sometimes been disappointed with the 9 centre points focussing. So, there could be problems under certain conditions when tracking with all points, but this is probably not unique to the Tamron.

19
Animal Kingdom / Re: Show your Bird Portraits
« on: March 28, 2014, 05:11:25 AM »
This could be a "bulbul".  I saw similar birds in Hong Kong Wetland Park.
-r

Focal length = 213mm, f/6.3, iso 1250, 1/40 s





This seems to be a Black-crested Bulbul (Pycnonotus flaviventris).


Hank
can you identify the other Asian birds I posted two pages back?
Thanks
Alan

20
Lenses / Re: Tamron 150-600mm AF servo issues?
« on: March 27, 2014, 05:45:59 PM »
for me.... personally... first rule of the supertele club: use a tripod.

for me it is much much more difficult to handhold a 600mm then a 300mm.

i am well over 1.90cm, 105 kg.. 4 days a week i go to the gym.
so weight is not the problem. :)
but even the smallest vibration will kill sharpness at 600mm.

then DOF is not that big with supertele lenses.
so when the AF is slightly off it has much more effect as with a 70-200mm, for example.

atmospheric effects reduce sharpness much more then with shorter focal length.

i get constantly sharp images with my 70-200mm even without taking care of my technique.
would i do the same at 600mm i would bring home only 5% keepers. :)

The 300 f/2.8 II + 2xTC III has rubbish autofocus on the Canon 7D. So, I sold the 7D for the 70D and the AF became fine. The Tamron 150-600 focusses well and reliably on the 70D and the 5DIII.

I have posted in the Bird Portraits thread in the last 24 hours loads of hand-held shots with the 150-600/5DIII, most of which are very sharp, even down to very slow shutter speeds, and nearly all of mine were keepers. Maybe your hands are shaking because you work out too much.

21
Animal Kingdom / Re: Show your Bird Portraits
« on: March 27, 2014, 05:11:00 AM »
Agreed that higher speeds are desirable. However, here is one example from two days ago at 600mm, 1/25 s, iso 640, hand held - again reduced to 1200px for uploading and a 100% crop.

22
Animal Kingdom / Re: Show your Bird Portraits
« on: March 27, 2014, 03:14:10 AM »
All hand held. The 600mm shots were at 1/40 - 1/250 s, which is on the slow side. An f/2.8 would have given extra edge.

23
Animal Kingdom / Re: Show your Bird Portraits
« on: March 26, 2014, 08:08:17 PM »
Finally

Focal length = 191mm, f/5, iso 1250, 1/160 s

I am very happy with the lens. The conditions were relatively dark and I had to use iso 1250 for most and relatively low shutter speeds. My 300mm f/2.8 II would have been better, but the Tammy was good enough, and pretty stunning on occasions, and I put it through most of its focal length range.

24
Animal Kingdom / Re: Show your Bird Portraits
« on: March 26, 2014, 08:01:46 PM »
Focal length = 300mm, f/5.6, iso 125, 1/250 s

This is at the sweet spot of the lens

25
Animal Kingdom / Re: Show your Bird Portraits
« on: March 26, 2014, 07:58:44 PM »
This is a Java sparrow
Focal length = 428mm, f/6.3, iso 1250, 1/250 s

26
Animal Kingdom / Re: Show your Bird Portraits
« on: March 26, 2014, 07:55:58 PM »
The last was a Zebra dove, and this may be a Java sparrow.

Focal length = 600mm, f/6.3, iso 1250, 1/160 s

27
Animal Kingdom / Re: Show your Bird Portraits
« on: March 26, 2014, 07:53:09 PM »
Focal length = 450mm, f/6.3, iso 1250, 1/1250 s

28
Animal Kingdom / Re: Show your Bird Portraits
« on: March 26, 2014, 07:50:40 PM »
Focal length = 213mm, f/6.3, iso 1250, 1/40 s

29
Animal Kingdom / Re: Show your Bird Portraits
« on: March 26, 2014, 07:48:19 PM »
Focal length = 600mm, f/6.3, iso 1250, 1/250 s

(emerald dove)

30
Animal Kingdom / Re: Show your Bird Portraits
« on: March 26, 2014, 07:45:20 PM »
Focal length = 309mm, f/8, iso 1250, 1/800 s

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