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Messages - AlanF

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61
Third Party Manufacturers / Re: Sigma and Tamron OS/VC quirks
« on: August 22, 2014, 01:38:28 PM »
My 150-600 doesn't have that problem or indeed any that others have reported.  My former 100-400L used to drift in IS.

62
Technical Support / Re: Another my Stupid question = Sensor Sizes
« on: August 22, 2014, 04:27:15 AM »
    No, for example a 36MP FF and 18MP FF using the same manufacturing technology, the 18MP FF will have better low-light properties as which pixel received more light than the 36MP FF.

Not true either - the world is awash with examples that prove the opposite: Nikon's D7000 has clearly superior how light performance to the D300; the Canon 70D is much better than the 30D; the 1D Mk IV is far superior to the 1D II!n.

And so on.

Smaller pixels do not mean inferior low noise performance.

Even DxO gets it:
http://www.dxomark.com/Reviews/More-pixels-offset-noise

To draw conclusions about pixel size and noise you must compare sensors with the same technology.  We know, for example, current Nikon sensors have much better S/N than equivalent Canon at low ISO. So comparing Nikon with Canon is misleading.

The DXO article says that the Canon 350D and 1Ds have identical sized pixels (6.4 micron) and identical S/N, which could be interpreted as it is pixel size that determines S/N. It then goes on to say that at the same field of view the 1Ds has better S/N than the 350D when both images are printed at the same size.  That is not due to the pixel size but results from the larger sensor of the 1Ds.

63
Technical Support / Re: Another my Stupid question = Sensor Sizes
« on: August 21, 2014, 05:47:49 PM »
There is a very recently started ongoing, now 11-page, thread on the topic - http://www.canonrumors.com/forum/index.php?topic=22161.0

64
Technical Support / Re: Another my Stupid question = Sensor Sizes
« on: August 21, 2014, 02:42:19 PM »
It's not really the size of the sensor that counts, it's the size of the pixel.

That's precisely back to front, Don - pixel size doesn't matter one little bit in terms of a sensor's light-gathering abilities, in any practical sense. Sensor size is the whole story, at any given "state of the art".

Jon Rista must've explained this about a million times on here - and he's completely, demonstrably right. Simply put, a big window lets in more light than a small one, whether it's made up of one pane of glass, or many - a perfect sensor analogy in this context.

That is a perfect sensor analogy: have a sensor made of one pane and it will have superb signal to noise and absolutely zero resolution.

65
Animal Kingdom / Re: Tamron 150-600mm bird pics
« on: August 20, 2014, 08:33:38 AM »
Very nice shots, Alan. Which body (5D or 70D) were these shot with? Do you prefer one or the other for use with the Tammy?

On the 5DIII. I prefer the 5DIII in general, but in practice there is little difference between the two. The better noise and IQ of the 5DIII balances the 70D's greater reach so both produce images of similar quality and resolution when you are cropping a small bird. For moon shots, which are basically monochrome, the 70D gave marginally better resolution in my tests, agreeing with jrista in his very careful analysis.

66
Animal Kingdom / Re: Tamron 150-600mm bird pics
« on: August 19, 2014, 09:35:06 PM »
Thanks Don, you have posted some great photos with the 150-600mm in the Bird Portrait's thread.

67
Animal Kingdom / Re: Tamron 150-600mm bird pics
« on: August 19, 2014, 08:20:23 PM »
Neotropic cormorant
Neotropic cormorant flying (at Lahave)

68
Animal Kingdom / Re: Tamron 150-600mm bird pics
« on: August 19, 2014, 08:12:54 PM »
Alder flycatcher
Blackcapped chickadee
and ending with my favourite - American goldfinch

Please add more photos.


69
Animal Kingdom / Re: Tamron 150-600mm bird pics
« on: August 19, 2014, 08:00:19 PM »
Nashville warbler
Blue Jay
American Robin

70
Animal Kingdom / Re: Tamron 150-600mm bird pics
« on: August 19, 2014, 07:49:41 PM »
Downy woodpecker
Hairy woodpecker
Northern Flicker
Blue Jay.

71
Animal Kingdom / Tamron 150-600mm bird pics
« on: August 19, 2014, 07:47:15 PM »
I have been on holiday in Canada for two weeks, walking with my Tamron 150-600mm and 5DIII. The birds are difficult to find - you suddenly come across small birds who will be around for a few seconds or minutes and then disappear. To get any photos you need a portable, reasonably long lens that you can swing into action in seconds. The birds are often hiding in bushes and you need IS for long exposures. My 300mm f/2.8 II + 2xTC III would have been the best solution, but the Tamron 150-600mm was more than good enough and more suitable for a holiday combining a family visit with the odd day for birding. Those knockers who have dismissed the Tamron in favour of a 400mm f/5.6L + 1.4xTC would have been completely stranded without IS - one of the exposures was as low as 1/50s and many in the 1/250 range. The 100-400mm would have been too short. The exifs are on the photos, which are all 100% crops, ie 1 pixel on the image = 1 pixel on the uncropped full frame. I was pleased with the haul. Most of the photos were in the Hammonds Plain area of Halifax NS.
The first 4: Canada Warbler 1/50s, Cedar waxwing, Black-capped chickadee, Ovenbird.

Please post images of your own from the 150-600mm Tammy.

72
Lenses / Re: Image quality with or without filters
« on: August 15, 2014, 06:09:49 AM »
In my experience I am very wary of filters. I have had some serious issues in the past with some makes of UV filters, not sure if the impact is more noticeable on long lenses.

Interestingly, only last week, I was asked to assess a brand new 400mm zoom lens whose quality appeared "not correct". Frankly it was awful, tried it on number of bodies, etc, etc. Then realised  that a UV filter (pretty high end and from reputable source) was placed on end - took it off - wow what a difference. I happened to have a competitors UV and also another brand protector and they didn't have the serious impact on image quality the previous one had

I tend to use high end protectors and always test when I get one (before and after) to check no significant difference. Frankly I was shocked that a reputable manufacturer's filter, fairly high end from a top UK manufacturer (meaning it wouldn't be a fake) was so poor.

So get a good one, form a reputable source, but test it when you get it....

What was the the bad filter?

73
Animal Kingdom / Re: Show your Bird Portraits
« on: August 14, 2014, 09:00:02 PM »
Just returned from the worst boat trip ever to see puffins from Peggy's Cove. The tiny vessel rocked so much in the waves that we couldn't stand up and one poor guy kept vomiting over the side. The captain briefly approached to within 100-120 metres to one part of the island and quickly turned back, within about 4 or 5 minutes. My wife couldn't use her binoculars because of the violent motion of the boat. I asked if we were going to do a circuit of the island and was told that nothing was to be seen the other side. Yet, when I checked Tripadvisor afterwards one delighted tripper wrote how they had circuited the island so the photographers could get every angle! I pointed the 5DIII plus Tamron at 600mm in the rough directions of the bird dots in the distance and fired at random at high speed. Surprisingly, I got some usable shots. The puffins occupy only about 150-200 pixels square of the image.

74
Photography Technique / Re: Questions about Shooting the Supermoon
« on: August 13, 2014, 12:29:29 PM »
Nice shots, Alan and Febs.

For everyone who likes to photograph the moon, you should really try on the non-full phases. There is SO much more detail when the moon is a large crescent, half, and gibbous. The closer it gets to full, the less relief there is to show off all the surface detail. The best times, really, are a few days before through a few days after half, as you get the greatest amount of relief during that period, and the moon is bright enough not to require long exposures (crescents can be challenging, as you often need to use longer exposures....and it's best to use the lowest ISO you can get away with, as DR is still immense.)

Just used my time machine and picked up the 300/2.8+2xTC en route.

Woow Alan,

That's a lot of detail. Which body your 5Diii or 70D ?

Jrista, you are wright to tell us not to take a photo during full moon.

5DIII. You realise FEBS is the acronym for the Federation of European Biochemical Societies!

75
Photography Technique / Re: Questions about Shooting the Supermoon
« on: August 13, 2014, 06:38:11 AM »
Nice shots, Alan and Febs.

For everyone who likes to photograph the moon, you should really try on the non-full phases. There is SO much more detail when the moon is a large crescent, half, and gibbous. The closer it gets to full, the less relief there is to show off all the surface detail. The best times, really, are a few days before through a few days after half, as you get the greatest amount of relief during that period, and the moon is bright enough not to require long exposures (crescents can be challenging, as you often need to use longer exposures....and it's best to use the lowest ISO you can get away with, as DR is still immense.)

Just used my time machine and picked up the 300/2.8+2xTC en route.

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