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Messages - AlanF

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406
Lenses / Re: Canon 400mm DO
« on: April 01, 2014, 09:54:05 AM »
You wrote:
"For all the pomp about the 300 f/2.8 ii, once you slap on that 1.4x iii converter, it's not a vast improvement in sharpness, if any, over the bare 400 f/4 DO...from looking at Bryan's test comparison at the-digital-picture.com."

All I have said was what you wrote does not match up with Canon's own measurements and a simple examination of Bryan's site. I am not defending anything or have any of the motives that you somehow have attributed to me. Could we please restrict this to rational discussion.

407
Lenses / Re: Canon 400mm DO
« on: April 01, 2014, 06:04:29 AM »
Canon's own MTF charts show the 300mm f/2.8 II + 1.4xTC III (bottom) to be significantly better than the 400 DO (Top).
ps
Just checked Bryan's TDP comparison: the 300 at 420mm is distinctly sharper

http://www.the-digital-picture.com/Reviews/ISO-12233-Sample-Crops.aspx?Lens=338&Camera=453&Sample=0&FLI=0&API=0&LensComp=739&CameraComp=453&SampleComp=0&FLIComp=1&APIComp=0

Well, I did too, and it's not "distinctly sharper" except in the extreme full frame corners.  I would say "somewhat noticeable" on the full frame borders, and "not much different in the center".

What about Canon's own MTFs? Have they got it wrong showing the distinct superiority of the 300 @ 420mm?

408
Lenses / Re: Canon 400mm DO
« on: March 30, 2014, 10:01:19 PM »
Most telephoto lenses give stunning results if you can fill the frame with the subject. The differences show up when the subjects fill just a small portion of the frame - the better the lens the smaller the image that can be used. To show what a lens is really capable of, you need to show the whole frame, a 100% crop of the image to illustrate the detail, the aperture, ISO, camera, shutter speed etc.

409
Lenses / Re: Philosophical question about Sigma Lenses - Why?
« on: March 30, 2014, 09:51:15 PM »
Sigma started off as a lens company and started making cameras as a sideline.  It makes its cash from lenses.
Fuji started as by making film, went into making cameras as a sideline before the advent of digital, which saved them as they were pre-adapted to digital.

What would happen if Canon started producing their lenses with other mounts? Well, there would be lots of happy Sony bunnies and maybe some Nikons. But, Canon might lose more of its profitable sales of bodies that rapidly become obsolete than it gains from long-lived glass. Canon has most certainly done the calculations and will stick to Canon-only lenses. 

410
Lenses / Re: Canon 400mm DO
« on: March 30, 2014, 10:25:54 AM »
The Tamron 150-600mm is the same weight as the 400 DO, costs less than 1/5th of the price, has much better IS, and you will have a shock when you compare them at 400mm:

http://www.the-digital-picture.com/Reviews/ISO-12233-Sample-Crops.aspx?Lens=338&Camera=453&Sample=0&FLI=0&API=0&LensComp=929&CameraComp=453&SampleComp=0&FLIComp=3&APIComp=0

411
Lenses / Re: Canon 400mm DO
« on: March 30, 2014, 09:30:30 AM »
Canon's own MTF charts show the 300mm f/2.8 II + 1.4xTC III (bottom) to be significantly better than the 400 DO (Top).
ps
Just checked Bryan's TDP comparison: the 300 at 420mm is distinctly sharper

http://www.the-digital-picture.com/Reviews/ISO-12233-Sample-Crops.aspx?Lens=338&Camera=453&Sample=0&FLI=0&API=0&LensComp=739&CameraComp=453&SampleComp=0&FLIComp=1&APIComp=0

412
Don
You are so right about turning on the self-timer by mistake. The SX50 is a fantastic little camera (I set up thread showing how it could for static photos out-resolve a 100-400 on a 5DIII). But, my wife turns on the self-timer every time so I have just bought her a touch-screen driven Ixus, which is basically foolproof. The little Ixus 310HS performs very well and I have just posted some photos in the City and Street scenes section.

The most important improvement would be to speed up the AF by using dual pixel technology.

413
Street & City / Is this you in the Shanghai smogscape?
« on: March 30, 2014, 08:32:51 AM »
Wandering around Shanghai's Pearl Tower with an Ixus 310HS in hand, I couldn't resist taking this shot of a Canon-lover posing posing for a Nikon.

You can see on the left how the distant buildings are lost in smog. This was a sunny day. It is so sad that Shanghai has this year succumbed to severe pollution. There follow a shot in mid-afternoon from the Pearl Tower over the smog-shrouded city, and another of relatively close buildings lost in the smog.

(All taken on the little Ixus 310HS I bought as a foolproof point and shoot for my wife last week - sold dirt cheap from the local dealer clearing out old stock. The little Canons are just so good).

414
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?

415
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.

416
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.

417
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

418
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.

419
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.

420
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.

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