Photoclubalpha

Just an update on this issue. I sent in my lens to SCS for repair. Got a nice surprise when they sent me a replacement lens as they didn't have the parts to fix the old one. So a thumb's up to Sony for rectifying the situation even though the lens was out of warranty. It was a pity the lens had AF p...

No error reports on either body. Just a failure for the lens to AF. The focus ring clutch is still engaged so I can move the focus until the AF point goes green and occasionally this is enough for the AF to revive temporarily (keeping the shutter button pressed). These (peizoelectric) ultrasonic rin...

It's an SSM lens so it's not a problem with the body screwdriver AF system. Battery was fully charged. It wouldn't work on the A700 (which was at room temperature and with a different battery). One hypothesis is that the clutch disengaging the focus ring could be having problems. If it doesn't disen...

DT 16-50mm SSM on A77 and A700. Took it out on the A77 today (about 8 deg C) but it worked OK. Managed to do some street photography with it, http://www.dkloi.co.uk/?p=999 http://www.dkloi.co.uk/wp-content/uploads/2012/11/DSC08907.jpg http://www.dkloi.co.uk/wp-content/uploads/2012/11/DSC08855.jpg I ...

Yup. Works when at room temperature (or above). Went out today (about 5 deg C) and after about 10 mins the lens starts refusing to AF. After a few more mins, the AF becomes even more sluggish and intermittent. Sometimes it can be "kickstarted" by manually focussing to the approximate focus...

Anyone seen problems with AF on a lens not working in the cold (not even below freezing) but recovering when back at room temperature? Could this be due to lubricant becoming too viscous or maybe the tolerances just on the wrong side of the distribution curves leading to binding under thermal contra...

Just got my copy today (it was a pleasant surprise) and I am not disappointed. Looking forward to further issues once I get my subscription sorted.

Cheers,
Daniel.

Yes, I'm favouring focus shift as the source of my woes. The Minolta 85mm/1.4 G still suffers from backfocus on the A580 under certain lighting conditions, as does the 50mm/1.7. It looks as if I'll just have to bide my time until a real successor to the A700 comes along with a large aperture AF syst...

Update: A580 back from the second repair. They replaced the AF module. They also calibrated the body to the two lenses I sent (at their request), 100mm/2 and Tamron 17-50mm/2.8. The letter they sent me said that my 100mm/2 has extreme backfocus tendencies. Funny, I never noticed it on my A700 or KM7...

[Edit 3] I done a bit more testing of the AF. Looks like the AF is spot on in daylilght. However, testing under compact fluorescents shows backfocus. This is unlike the A700 which AFs accurately under both conditions. Examples below with the 100mm/2. DSC02996.JPG DSC02995.JPG Note that adding the fl...

Just checked it, it does show the percentage on the rear screen. My impression is that the difference is greater than the 10% labelled difference in capacities. Actually, the ones I have are marked "7.2V 11.8Wh" which works out to roughly 1640mAh. The bottom line is that the ones I got wor...

I got some cheap spare batteries for the A700 at 7dayshop (currently £8). The don't seem to last as long as the genuine Sony batteries but haven't had any compatibility problems either. I use them as emergency spares in the camera bag but use the genuine ones mostly. http://www.7dayshop.com/catalog/...

Just a short report on my experiences with having my A580 repaired by Sony Service in the UK. I hope this will be helpful for anyone else in the UK who may come across a problem with their Alpha. I rang up Sony just after New Year to ask about getting my A580 repaired. After I explained the problem ...

[Step 2. Derive G channel from (R+G)-R and (B+G)-B. Great proposal :lol: You kill your S/N ratio right away. Your derived G's would have about sqrt(3) more noise than Bayer from just the photon noise. Then you pile up systematic errors due to inequality of sensitivities of R and B in pure channels ...

Daniel, I think I know what Agorabasta is on about. A typical camera lens produces three sizes of images for R, G and B channels - we use the G channel, which represents the middle magnification across the wavelength range for a non-apochromatic lens, for luminance and this also has twice the spati...