which lens to buy?

[agorabasta]

David, are you sure that's exactly the defocus or could it be some shake blur from the IS malfunction or from some sensor-cleaning shake routine taking too long to complete (laggy routine)?

[Greg Beetham]

Yeah that occurred to me as well, the A77 AS not getting the shake resonance correct for the focal length in use at the time, but that would be rather obvious blur to figure out one would think, I mean it would not necessarily look like de-focus blur…would it? I suppose if the error was very small it might look like soft focus and I don’t know if that solution would work for some of the NEX oddments or not either.
David why not turn it on with AS turned off for a couple of telephoto shots, also with AS turned on before you turn the camera on.
Greg

[Dusty]

So we went from First Frame Black to First Two Frames OOF? (or FFB to FTFOOF.)

Seems like Sony really SHOULD have done an A750, just stuffing the best 16MP sensor into the 700, and given it more time to work on it's new wonder-dog. (Part wonder, part dog!)

Dusty

[redsim74]

Seems like Sony really SHOULD have done an A750, just stuffing the best 16MP sensor into the 700

Yes please, Santa!

[[SiC]]

Seems like Sony really SHOULD have done an A750, just stuffing the best 16MP sensor into the 700

Yes please, Santa!

I'll have one too

[agorabasta]

No way! Sony want you to pay twice. First get an a77, then a Nex7+adapter. First one delivers in-body IS, the second one brings good low-noise performance. Because you really cannot have those two nice properties together at current sensor densities without overheating.

And then you also get vibration-free first electronic curtain and no mirror slap. And these two things are no small feat - I would never believe how many perfectly sharp keepers they produce together at 1/5s 35mm, and now that rate is about 80% with my 5N. And that really means we don't need any IS below 50mm, and then we'd better have in-lens IS at the long end anyway...

So where does it lead us? Seems like a large Nex body with a dedicated a-mount kit adapter may be the ultimate solution.

Then maybe the a77 is a mere stop-gap? Or will there continue to be those two systems, just to maximise the sales?

[Greg Beetham]

I think the bean counters looked at how much money the A77 R&D had cost to date and told the wiz kids it’s time too stop fixing it and start selling it, thus once again snatching defeat from the jaws of victory.
But yes Dusty I think you are right, if Sony had had a timely A750 out there earning it’s keep in the meantime, (a year earlier) the A77 team would have had less pressure building up on them to deliver the A700 replacement…
Greg

[David Kilpatrick]

I know this is not shake induced blur. If I had to guess, I would say the lens is being repositioned.

However, for your further interest, I was shooting some close-up samples today using 24 mpix A77, 24 mpix A900, and 22 mpix M645ZD. The best by far was the A77 despite my using the cheapest lens option - I decided to get a Sigma APO 70-300mm Macro while they are still made.

The M645 shots were of no use at all as despite very careful visual focusing, this focus point was wrong. Also, during shooting one frame was totally corrupted, and one frame shot at f/11 was two stops darker than the correct exposure at f/22, despite using studio flash. So far not impressed by the reliability of the medium format option!

David

[Greg Beetham]

David how does the other one behave? the Phase One that's in Richard's studio, is it reliable and consistant?
Greg

[David Kilpatrick]

Phase One backs are much more reliable. I have to determine what the issue is, because the lens in use (Mamiya 120mm Macro MF) only stops down to f/22, and how f/11 can manage to be darker than f/22 is baffling.

I may go for a refurbished Phase One P45 back which will give me the angle of view I want, plus the extra image size, plus one hour exposure capability. If I do, it will have to last a good few years. But I may equally just send Richard my spare lenses and sell the kit I bought and take a small loss for the sake of the experience.

What I am finding - slowly - is very simple; the A77 is exceptionally good but needs perfect conditions and handling to get the best.

David

[mikeriach]

David,
Going back to the original subject, I guess you still feel the 16-80 is the optimum walk about lens despite the problems with the A77?
Did you manage to bottom that out or is it perhaps connected to the software update?
Santa might be lens hunting for me!
I'm also wary of limiting the focal length range by going for a 2.8 option.
Mike

[agorabasta]

I know this is not shake induced blur. If I had to guess, I would say the lens is being repositioned.

As long as it's definitely not the shake blur, there's another self-evident reason.
As you switch the cam on, it starts to heat up; then until the heat-up process settles, there are temperature and pressure gradients everywhere. The most important place to affect the image is the sensor assembly, as the sensor heat changes air pressure inside the sandwich, and the local temperature gradients also create tensions. So until it all settles, the LPF and the sensor itself are deformed and misplaced against each other.

So that is a design limitation that may be only addressed in the future designs. And now we need to let our cams to warm up like some century-old radios did...

[johna901]

If Viceroy is right, the fault should show up with all A77s. If on the other hand, David has a faulty sample, others should not observe the problem. Maybe you need other A77 owners to report in?

[artington]

Whew!! Having read through - but not understood much of the technical detail in - this elongated posting my conclusions are:

- both the a77 and the NEX-5N have IQ and possibly DOF issues under certain conditions which may be down to the camera design, sensor build or linked to certain lenses but no-one is certain which of these applies. Whichever the case, such unpredictable lack of uniform behaviour renders both flawed, in my estimation.
- the curious behaviour of the 16-80CZ on David's a77 might suggest that his initial poor opinion of the 16-50/2.8 may be revised for the better - any thoughts on that yet David?
- if these issues are reflecting technological glitches which should have been ironed out before release (like the Leica M8) but weren't because commercial pressures took over, what might this also mean for the NEX-7?

All this prompts me to take a back-seat, happy as I remain with my a900 and NEX-5, and wait for some considered appraisal of the NEX-7 before buying one (unless impatience simply takes over after the long and tantalising delay, which well it might )

[agorabasta]

But the DoF issues play also in the other direction, they don't only rob you of DoF - they may produce some more DoF where it simply should not be.

Check the 5N sample below, shot with SEL18200 @f/9 43mm, focus point about 25m away, all's sharp into distance till natural haze allows to see. But quite inexplicably, the part right at the bottom at 2.5m away is also within DoF, as are the flowers and grass blades in the lower left corner. If you try some calculations, there is absolutely no setting that could produce such DoF config in theory.

(and btw, that SEL18200 is a fabulous lens)