A900 crop vs. A700

[David Kilpatrick]

The Alpha 900 viewfinder is roughly 18% smaller in absolute subject scale at a given focal length; it's a difference, but not enough to render it unusable. The extra brightness and clarity given by the condensor in the place of a fresnel makes everything look far sharper anyway. You could compare the difference to using a top grade pair of 8 x 40 binoculars (A900) instead of a good pair of 10 x 30 binoculars (A700).

The focus assembly occupies exactly the same real area as the A700, so if the subject is more or less in the APS-C central frame, focusing issues are identical but the A900 has less chance of losing the subject between focus points in wide area mode.

Zooming back with the APS-C A700 does not function in the same way for ensuring movement remains within the frame, because you start with 12 megapixels not 24, and the equivalent crops would to a 5.3 megapixel file size. While a 10 megapixel crop from 24 is OK, a 5 megapixel one is a bit limited. The same would apply to using the D3 the way I describe. The D3 is only 12 megapixels, and while it crops very well (it's 12 outstandingly clean megapixels!) using the D3X for field sports with a wide range of unpredictable action and ball movement is now becoming standard for sports shooters - especially football where a pass can change the focus of play in a split second.

When I started out in newspapers (1970), some of the photographers still preferred to use their Rolleiflex for football (one or two even used 5 x 4). The reason was simple enough, they got the money shots when the new kids on the block with their Nikkormats, Canon FTbs and Pentax S3s were missing the shots. Even the Novoflex follow focus system resulted in too many unfocused shots, and far too many with half the player cut off or the ball out of shot.

The Rolleiflex with 75mm or 80mm lens could be set to cover half the pitch in a single view, and the photographer could focus between the near and far touchlines by estimation, turning the focus knob between two points while holding a cable release in the other hand. They didn't even look through the finder. They watched the game instead, and could move the camera to cover one end or the other of the pitch just using two points on the tripod head pan. They got perfectly timed single shots of key moments, because the release was instant (no mirror) and they could watch the action directly (no viewfinder). In the darkroom, the 6 x 6cm negative easily yielded a blow-up of just the players involved in the action. They did not worry about it being slightly out of focus or very grainy.

The D3X is not quite used this way, but with a relatively loose framing (70-200mm lens - hence Nikon being bombarded with requests for a new version, just announced, with better edge of field sharpness) to make sure the action is always in the frame and much easier to follow. They then pull 3mp, 6mp, 12mp or whatever might be needed from the frame.

David

[Greg Beetham]

Yah, it's logical that that would work quite good, especially with the med format coverage compared to the rudimentory 35mm AF on tele lenses of that era, in any case even with todays cams I bet they blast off lots and lots of frames in the hope that there will be a good percentage of winners...
The thing that is tough is, taking photos of reasonably small things from intermediate distance, it probably stems from the original design of the camera...ie. the original capability was more biased towards scenery or groups of people...large things, it probably was a long time before genuine macro ability emerged or even telephoto macro..
That's where I see the superiority of APS-C, when shooting at something small like birds, especially ones that are a bit nervous and jumpy, you have to have everything going for you, you can't afford too have the camera focussing on something other than the subject, (because the bird is often in position for a few moments only) the subject has to be a reasonable size in the frame anyway to even have a chance of the camera focussing on it and not something else, (if the area where the subject is is cluttered with leaves and branches).
I still reckon that in shooting small things APS-C easily beats FF (more DOF is also a bonus), because if you actually want to take a better photo of something small you have to hump a much bigger lens around to actually get more pixels under that subject, most of the time a FF shooter would be lucky to even get as many pixels under a given small bird subject as an APS-C shooter would, never mind more.
Greg

[bossel]

5 posts in a row and then 12 If you want others to get your message, be short and precise. Just a free advice

[bossel]

Don, I am trying to help you. Most won't read all your posts and give up somewhere in the middle. Summarize your point in one post so we have a chance to follow.

Btw I do own a Sigma 70-300 and it gets little use. If I want to go light, I use the 18-250, if I need better I use the beercan. If I need 300mm, I crop or uprez my pics. I certainly can crop my 12mpix to 6mpix and this changes 210mm into 300. Or I uprez my 210mm @F4 to 300mm, the Sigma at 300mm does leave some room for improvement, even at F8 or F9.

[bossel]

I quickly have to post something before you add another dozen replies in a row

My reply did concern cropping and/or uprezzing on APS-C. And consider APS-C cropped to 6mpix being like FF cropped to APS-C. Get it?

Also, I added my own experience with lenses and PP which might interest others owning these lenses.

No need to comment on your reply or squirrels I have seen a dozen of times. Yawn.