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Author Topic: A900 Update  (Read 45801 times)

Deep

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A900 Update
« Reply #60 on: September 24, 2008, 04:22:33 am »

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Deep,
Thanks for your trouble in providing this shot. However, I don't see any crops of corners. You've shown an edge which appears to be okay considering the low resolution of the scene, but even with this edge, we can't be sure about resolution fall-off because there's no fine detail (hairs, grass stalks, grains of sand).

Glossy paint is just not an ideal target for checking resolutiuon.

In any case, many good Canon lenses are also okay up to the edges. The middle of the extreme edge of a 35mm frame is only 18mm from the centre. It's the area from 18mm to 22mm (from centre) which represents the corner. It's this area where most lenses show a marked softness with full frame 35mm.
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?? The crop is the top right corner, not just the edge.  Admittedly, to the right, it is coming out of the plane of focus but that is different to the lens being soft.  The top post is in the plane of focus and is also not soft.  Okay, not a perfect example but enough to see what's going on.  Also, this is unsharpened - a tiny bit of sharpening that you need for pixel-peeping reveals more subtle detail in the paint than a casual glance would suggest or than a poor lens would resolve.  It's easy for even a poor lens to resolve hair or sand.  In those cases, the detail appears sharp by default.  Subtle edges of brush strokes will just vanish with low resolving power, so this is actually quite a useful, if boring, example.

What the crop does not show is how similar the detail is right across - but that would have been a 16MB upload!  I didn't keep too many 24-70 shots.  I was more interested in the 85/1.4 and even then, I was more worried about the "look" as a portrait lens than edge sharpness.

Many Canon lenses are okay to the edges, yes.  My 24-70L was excellent, even with very fine grain slide film like RSX which resolves as much detail as a 24Mp sensor.  Other Canon lenses, like the 24-85 and cheaper zooms, could not outresolve RSX when I tried them.  I have a stack of Canon primes which are superb too but this discussion is about whether the Zeiss lens is sharp across the frames.  I've tried one example and it was.  Until you try one for yourself, you'll probably keep worrying!

Happy shooting
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Don

ErikKaffehr

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A900 Update
« Reply #61 on: September 24, 2008, 09:50:15 am »

But,

In many situations you really need a zoom. Maybe that Zeiss 21/2.8 is a bit better than the Nikon 12-24/2.8 but zooms are much harder to make than single focals.

I often find myself in situations where I need the right focal length or I need to crop. In theory I would love single focals but in practice I would never use them.

Any lens should be sharp corner to corner at medium apertures like f/8 to be really useful. Some aberrations like lateral chromatic aberration and distortion can easily be compensated so I don't care that much about those.

Erik

Best regards
Erik

Quote
I don't think anyone is saying that the lens is bad. It's just that corner resolution is the big disadvantage of full frame, and 24mp full frame is likely to show a greater difference than 12mp in the corners.

The sample images linked above have not been taken in order to display corner resolution so it's still a moot point.

Now the new Zeiss 21/2.8 Distagon really is sharp from corner to corner on the 1Ds3; clearly better than the Nikkor 14-24/2.8.
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douglasf13

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A900 Update
« Reply #62 on: September 24, 2008, 01:31:47 pm »

FWIW, both my ZA 85 and ZA24-70 are at their optimum performance at f4.  Actually, the 85 is very similar between f4 and f5.6
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aaykay

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A900 Update
« Reply #63 on: September 27, 2008, 02:50:04 pm »

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I'm afraid I subscribe to the 'seeing is believing' school of thought   .
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Absolutely !  These are not nickel and dime purchases and one has to be totally convinced before purchasing it....I agree.  

But remember, this lens is a 2007/2008 design, specifically created for a high pixel density Full-frame sensor.  What all of these images show, is just an indication of how it performed on the A900 - which was a BIG unknown, till Sony actually released the Full-frame camera.  

Sony obviously intends to establish their "system" differentiation from the other players in the Full-frame marketplace, by their leveraging of Zeiss and its excellent optical designs and ultra-high-end Schott Glass, allowing them to leapfrog the competition on the "lens/glass" aspect.  Bringing out this lens as a Sony/KM "G", would simply bring such a lens at par with a Canon "L" or the equivalent Nikon high-end version (in fact, Konica Minolta did have a 24-70 f/2.8 design, ready to go, when they were bought by Sony but Sony decided not to use the design, and went with Zeiss for this critical FF lens - great move, IMO).  There is an upcoming 24-105 f/4G SSM, which will obviously be cheaper and function as a probable "kit lens" for the A900, similar to the function served by the Canon 24-105 f/4L IS.

As an aside, I just purchased the CZ 24-70 f/2.8 (VERY difficult to obtain, since it was on backorder almost everywhere, even though our local high-end retailer had one in stock, NIB).  Bought the CZ 85mm f/1.4 too.  Just waiting for the A900 to be shipped (supposed to be end of October), since using these lenses on the A700 seems to be under-utilizing their capabilities. I was totally convinced (based on the images I saw), that there will not be any problems whatsoever, with these lenses, on the A900.  The highest vote of confidence - voting with one's wallet   We will see.
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Ray

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A900 Update
« Reply #64 on: September 27, 2008, 08:31:03 pm »

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But remember, this lens is a 2007/2008 design, specifically created for a high pixel density Full-frame sensor.  What all of these images show, is just an indication of how it performed on the A900 - which was a BIG unknown, till Sony actually released the Full-frame camera. 
[a href=\"index.php?act=findpost&pid=224979\"][{POST_SNAPBACK}][/a]

I would fully expect the Sony 16-35 to have significantly better edge and corner resolution than my Sigma 15-30. If it didn't there would be something seriously wrong.

However, if you are going to demonstrate corner resolution, then you must show some actual corners that are in focus and which contain detail, as in the following shots which demonstrate how bad the Sigma zoom is in the corners and how relatively acceptable it is around the middle of the far edge.

The following shot was hand-held at 1/50th second, F5.6 and ISO 1600 on the 5D, using the Sigma 15-30 zoom at 15mm.

In order, from left to right; (1) the full uncropped scene; (2) the full left edge; (3) the bottom left corner. Sharpening has been applied, but no noise reduction.

[attachment=8546:attachment]  [attachment=8551:attachment]  [attachment=8549:attachment]
« Last Edit: September 27, 2008, 08:51:56 pm by Ray »
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Ray

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A900 Update
« Reply #65 on: October 05, 2008, 01:58:17 am »

Quote from: EPd
I did a quick shot of the MTF curves published by Sony for the CZ 16-35. Especially at full opening not very impressive in the corners. It's not on my wishlist (also because I have primes fish-eye 16mm, 24mm 2.8 and 35mm 1.4).

[attachment=8702:Sony_CZ1...TFcurves.jpg]

Dear me! Those curves do look rather unimpressive, except those for 35mm at F8 which seem exceptionally good; so good in fact that they are unbelievable. I can't believe a lens can be that sharp in the centre at F8. Here are the Photodo curves for the Canon 35/F1.4 prime.

[attachment=8707:30mm_F1_4.jpg]
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Ray

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A900 Update
« Reply #66 on: October 05, 2008, 08:50:55 am »

Quote from: EPd
The curves Sony provides seem to match closely what I have seen from independent sources, so in this case (where I haven't seen third party curves) I expect them to be rather accurate too. Wait until you see the Sony CZ 24-70 MTF curves if you find these hard to believe!

It's the claimed performance of the lens within a circle of about 8mm diameter in the centre of the frame that I find difficult to believe. Contrast at 40 lp/mm and F8 is 95% and higher. That seems to me to be better than the laws of diffraction would allow.
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stiksandstones

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A900 Update
« Reply #67 on: October 05, 2008, 12:46:22 pm »

I was thinking about looking into an a900, but just saw the 300 2.8 (lens I use 60% of the time) is $6000.
But camera still looks promising.
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Fine_Art

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A900 Update
« Reply #68 on: October 06, 2008, 12:31:54 am »

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Ray

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A900 Update
« Reply #69 on: October 06, 2008, 01:54:05 am »

Quote from: Fine_Art
New review

British Journal of Photography

After reading that, I'm reminded of the adage, 'A picture is worth a thousand words'. In fact, I think we could amend that adage to, "A picture, plus a complete set of accurate MTF charts, is worth 100,000 words".
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Ray

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A900 Update
« Reply #70 on: October 08, 2008, 08:32:34 pm »

In dpreview's review of the Nikon D700 (just posted) there's a high-ISO noise comparison between the Nikon D700, and Sony A900.

It's not looking good for the A900. Even the 5D appears to have less noise at ISO 3200 than the A900. At ISO 6400, the D700 looks a world apart from the A900.

I know when comparing different size images resulting from sensors with a different pixel count, one should either uprez one image, or downsample the other image, so that one can compare equal size images. I don't know why dpreview doesn't do that. It certainly affects the appearance of noise and generally seems a sensible thing to do because most people do not size their prints according to the native resolution of their camera's sensor. (Sorry, I can't make a print bigger than 12"x18" from my D700 because that's the size I get at 240ppi   )

However, I just can't see that upsizing the D700 image is going to make the A900 image at ISO 6400 look anywhere near as clean and sharp as that upsized D700 image. The noise difference is so huge.

On the other hand, I do have some reservations about the jpeg nature of these shots. I get the impression they are out-of-camera large/fine jpegs with NR settings at default or standard.

http://www.dpreview.com/reviews/nikond700/page17.asp
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Deep

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A900 Update
« Reply #71 on: October 08, 2008, 09:49:44 pm »

Quote from: Ray
In dpreview's review of the Nikon D700 (just posted) there's a high-ISO noise comparison between the Nikon D700, and Sony A900.

It's not looking good for the A900....

...However, I just can't see that upsizing the D700 image is going to make the A900 image at ISO 6400 look anywhere near as clean and sharp as that upsized D700 image. The noise difference is so huge.

Maybe, but in the far more useful sensitivities up to 1600, there is no way the D700 is going to match the detail of the A900, which gives a huge amount of headroom for noise reduction on your computer later.  1600 with one of those fast lenses (and anti-shake built in) is going to work in any sane amount of light, even without a tripod.  And we haven't even seen what you can get out of the RAW files yet.  I'd respectfully have to argue that it's looking very good for the A900 - until we see what the 5DII comes up with!
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Don

Ray

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A900 Update
« Reply #72 on: October 08, 2008, 11:03:52 pm »

Quote from: Deep
Maybe, but in the far more useful sensitivities up to 1600, there is no way the D700 is going to match the detail of the A900, which gives a huge amount of headroom for noise reduction on your computer later.  1600 with one of those fast lenses (and anti-shake built in) is going to work in any sane amount of light, even without a tripod.  And we haven't even seen what you can get out of the RAW files yet.  I'd respectfully have to argue that it's looking very good for the A900 - until we see what the 5DII comes up with!

Agreed! At lower ISOs the A900 will deliver greater detail, otherwise there'd hardly be any reason for buying it. Clearly, these sorts of issues depend on your usage. Most folks will attempt to use the lowest ISO possible, consistent with a shutter speed that is fast enough for a sharp image.

But there is a dilemma here, when you know (if this proves to be the case) that image quality definitely suffers at high ISO, but also suffers at low ISO due to a shutter speed which may be too slow for the movement of the subject, if not for the movement of the camera. One is sort of caught between a rock and a hard place.
 
The dpreview comparisons indicate to me, if one is in a situation where ISO 6400 (and possibly even ISO 3200) is required for a sufficiently fast shutter speed, the D700 will deliver better image quality than the A900, period.

When the subject is moving quickly (a croc or a whale jumping out of the water, a footballer jumping for the ball), image stabilisation and/or tripod doesn't help much.

Speaking for myself, I want as far as possible a general camera which is adequate in all situations. I don't want to carry a D700 and at least one Nikkor lens for high ISO performance; another camera for best detail at low ISO, and yet a 3rd, cropped format camera, as a lens extender for my longest telephoto.

I would prefer a 39mp Canon full frame with image quality at least equal to that of the D700 at ISO 6400 (viewing equal size prints), and which has sufficient pixel density to make my 50D redundant as a lens extender. In the meantime, I'll probably settle for a 5D MkII. When its ISO 6400 images are downsized to 12mp, I wouldn't be surprised if image quality is on a par with that of the D700 at ISO 6400.
« Last Edit: October 08, 2008, 11:32:11 pm by Ray »
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Deep

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A900 Update
« Reply #73 on: October 08, 2008, 11:32:19 pm »

Quote from: Ray
Agreed! At lower ISOs the A900 will deliver greater detail, otherwise there'd hardly be any reason for buying it. Clearly, these sorts of issues depend on your usage. Most folks will attempt to use the lowest ISO possible, consistent with a shutter speed that is fast enough for a sharp image.

But there is a dilemma here, when you know (if this proves to be the case) that image quality definitely suffers at high ISO, but also suffers at low ISO due to a shutter speed which may be too slow for the movement of the subject, if not for the movement of the camera. One is sort of caught between a rock and a hard place.
 
The dpreview comparisons indicate to me, if one is in a situation where ISO 6400 (and possibly even ISO 3200) is required for a sufficiently fast shutter speed, the D700 will deliver better image quality than the A900, period.

When the subject is moving quickly (a croc or a whale jumping out of the water, a footballer jumping for the ball), image stabilisation and/or tripod doesn't help much.
I've photographed whales jumping out of the water, horses doing cross country, weddings in very dark chapels, portraits in evening light, flying birds on gloomy days - none of which are suited to tripods or helped much by anti-shake (except the weddings).  I've never, ever, needed more than 1600.  My point is 1600 is already extreme sensitivity and 3200 only adds one stop to that.  The situations where "ISO 6400 (and possibly even ISO 3200) is required for a sufficiently fast shutter speed" almost don't exist for the vast majority of photographers.  I'd go so far as to argue that the situations where having video available or being able to crop heavily are far more common.  (Makes Canon look quite clever, really!).  But, okay, if you have some project where you work in near dark, can't control the light and don't need the camera's best performance, the Nikon will be marginally better, granted.  At 1600, looks like there will be little to choose either way.

There is a current infatuation with high sensitivity performance.  That's not a bad thing in itself but it is massively overrated today.  All current DSLRs produce good photos in bad light and the best perform better than nearly anyone needs.  Most of us are adequately served by current poor light performance but we can use better highlight control and better detail capture.  Well, both D700 and A900 do well with highlights (not that I've tried the Nikon but it looks promising) but the A900 is clearly vastly better at detail capture and it appears it holds the advantage to about 1600 "ISO".  Brilliant!
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Don

Ray

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A900 Update
« Reply #74 on: October 09, 2008, 12:13:06 am »

Quote from: Deep
I've photographed whales jumping out of the water, horses doing cross country, weddings in very dark chapels, portraits in evening light, flying birds on gloomy days - none of which are suited to tripods or helped much by anti-shake (except the weddings).  I've never, ever, needed more than 1600.

There's a difference between needing it and wanting it. Most people accept the limitations of their equipment and then rationalise to themselves that they don't need such performance. When I'm using a 400mm lens on the Daintree river on a dull day, trying to photograph small birds flitting around in the foliage on the river bank, I sometimes find I'm shooting at ISO 1600, F8 (which I prefer because it's the sharpest aperture on the Canon 100-400 zoom) and 1/60th second. So I drop down to F5.6 and get 1/125th. It's still not fast enough for a truly sharp, high quality image with the cropped format 40D which turns the lens into 640mm in full frame terms.

There are two solutions to this problem. Buy a big, heavy and very expensive 400/2.8 prime which is as sharp at F2.8 and/or F4 as my 400 zoom is at F8, plus a Sony A900. Or just buy a camera that produces higher image quality at high ISO. Image comparisons I've seen so far indicate that, even at ISO 1600, the slightly lower pixel density 1Ds3 produces sharper and cleaner images than the A900.

For all practical purposes, the 5D MkII is close enough to the 40D when its images are cropped to the same format size. I would find it very useful to be able to use the 5D2 at ISO 3200 in circumstances where I would use the 40D at ISO 1600 and half the shutter speed. I'll be disappointed if 5D2 image quality at ISO 3200, pixel for pixel, is not equal to the 40D at ISO 1600.

Another way of looking at this is to ask oneself, if Canon were to have simultaneously released an 8mp cropped format (upgrade to the 20D) using 5D2 pixels and the improved technology associated with the 5D2, would such a camera have a one stop high-ISO improvement over the 20D, bearing in mind that the general image quality improvement of the 40D, compared with the 20D, is negligible?
« Last Edit: October 09, 2008, 12:31:56 am by Ray »
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Ray

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A900 Update
« Reply #75 on: October 09, 2008, 01:58:14 am »

I don't wish to sound negative about the A900. Everyone's uses and purposes are slightly different. Since I already have a few Minolta lenses which are very good according to Photodo tests, I'd really like to buy the A900, if it were to offer the sort of performance which at least equalled and hopefully exceeded that of the 5D2.

The extra few megapixels are neither here nor there. The Sony 16-35 lens does not appear to be better than (or even as good as) the Nikkor 14-24, and just yesterday I received, at long last, a Nikon/Canon adapter from Mark Welsh.

I can find no reasonably lightweight zoom lens in the Sony/Zeiss repertoire that can better the quality of the Canon 100-400 IS F4.5-F5.6 (a lens I use a lot) and Zeiss is now offering the superb 21mm Distagon with a Canon mount, so I can find no good reason to buy an A900, which is a pity, but I have to be realistic.

I'm also rather concerned about the following 'cons' from the updated Imaging-Resource review of the A900. I quote:

Quote
. Some image noise even at ISO 200

. At anything above ISO 200, noise limits maximum print size before resolution becomes an issue.

. High-ISO performance doesn't match that of Canon EOS-1Ds Mark III (Which is also 2.6x as expensive though)

. Dynamic range less than that of many current models

Whilst the Canon 1Ds3 might be 2.6x the price of the A900, indications so far are that the image quality of the 5D2 will exceed that of the 1Ds3 by at least some margin, however small.

Hope you don't think I'm being brutal  
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Deep

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A900 Update
« Reply #76 on: October 09, 2008, 02:26:17 am »

Quote from: Ray
Hope you don't think I'm being brutal
Not at all - it's your money!  It is, however, a fair amount of money and you'd be either very rich or impetuous if you spent it before you tried the options out.  A camera in the hand is very different from the theory.

It also sounds like you could do well to look sideways at other options.  I would consider being forced to use f8 to get a sharp photo and sufficient depth of field in that situation inexcusable....
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Don

BernardLanguillier

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A900 Update
« Reply #77 on: October 09, 2008, 04:04:13 am »

Quote from: Ray
In dpreview's review of the Nikon D700 (just posted) there's a high-ISO noise comparison between the Nikon D700, and Sony A900.

It's not looking good for the A900. Even the 5D appears to have less noise at ISO 3200 than the A900. At ISO 6400, the D700 looks a world apart from the A900.
http://www.dpreview.com/reviews/nikond700/page17.asp

Ray,

Sorry to be franck, but what you write here looks like non sense to me. The A900 is a high pixel camera and its field of application is not high ISO.

Canon might have done a slightly better job with the 5DII, but that camera is one year younger than the D3/D700 technologicallywise. You can be 100% sure that the successor of the 1d3 will have better image quality at high ISOs simply because a 20+ MP camera will never be as good with high ISO noise. The 5DII is also not a real high ISO camera.

So I don't know why you are even considering the A900 and feel like you have to repeatedely run it down. It has never meant to be a camera for you if high iso noise is the only think you consider important in a camera, but that doesn't take anything from its value for most photographers.

Cheers,
Bernard
« Last Edit: October 09, 2008, 04:10:46 am by BernardLanguillier »
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Ray

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A900 Update
« Reply #78 on: October 09, 2008, 07:10:53 am »

Quote from: BernardLanguillier
Ray,

Sorry to be franck, but what you write here looks like non sense to me. The A900 is a high pixel camera and its field of application is not high ISO.

Canon might have done a slightly better job with the 5DII, but that camera is one year younger than the D3/D700 technologicallywise. You can be 100% sure that the successor of the 1d3 will have better image quality at high ISOs simply because a 20+ MP camera will never be as good with high ISO noise. The 5DII is also not a real high ISO camera.

So I don't know why you are even considering the A900 and feel like you have to repeatedely run it down. It has never meant to be a camera for you if high iso noise is the only think you consider important in a camera, but that doesn't take anything from its value for most photographers.

Cheers,
Bernard

Bernard,
Be as frank as you like. All I've got to go by is what I see and read on review sites such as Dpreview and Imaging Resources. If they have got things wrong, or, if I've misinterpreted their results, please feel free to point out my errors.

I've been considering the A900 ever since I heard about it because (1) I expected it to be more affordable than the 1Ds3, which it is, (2) I have a 24" wide format printer and would appreciate the additional detail provided by a 24mp sensor, (3) I already have a bunch of Minolta lenses.

Aren't those good reasons?

High ISO performance is not my only criterion. Availability of better quality lenses in the range that I currently use a lot, but feel is a bit inadequate, is an important consideration; specifically lenses in the wide angle range of 15-30 and the telephoto range of 100-400.
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Ray

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A900 Update
« Reply #79 on: October 09, 2008, 07:31:07 am »

Quote from: Deep
It also sounds like you could do well to look sideways at other options.  I would consider being forced to use f8 to get a sharp photo and sufficient depth of field in that situation inexcusable....

It's not inexcusable. The excuse is very good. I'm not aware of any other options that are not too expensive and too heavy. The Canon 400/2.8 at F4 would no doubt be sharper than the 100-400 at F8. However, it simply doesn't fit my purposes because of its weight and its inflexibility because it's a prime.

None of the zooms in this range that have been tested at Photozone, whether Nikkor, Sigma or Tamron, are better than the Canon 100-400. They all have below par resolution at their maximum aperture of F5.6.
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