Thanks for your replies (JeffM & Wake Turbulence)!
As soon as I have my own PC
repaired (it crashed on Friday, 13th), I will follow your advise (starting again from the original - which is on my PC
- and limit it to 1024pix - then have a look again!). I am currently working from the kids' PC
, which lacks my originals and which has a lower quality screen... so, I will refrain from uploading from this station! (I had the idea that at 1600pix, more detail from the original would remain, but I see now that rejection is also more likely at that size!).
Canon 347d mkII ;-) - EFS10-22mm f/3.5-4.5 USM - EFS18-55mm - EF28-105mm f3.5/4.5 - EF100-400mm f4.5-5.6l IS USM - ...