No. I downloaded the photos twice thinking that iphoto would skip the dupes they wat windows did.
In events or photos, the thumbnails are side by side. Before I deleted any of them I opened each one and they were the same.
If the dupes were in one section it'd be easy but they are all side by side to the first downloaded photos, So I have to delete or mark one photo then skip and mark the next photo then after doing this drag them to trash. I can still open the remaining photo and it is the same quality as the dupe I deleted.
Some photos are perfect. Others are in bad shape, but on the PC there is no problem enlarging them and they look fine with no destortions.
I can not just delete the library and re download because I have new unique photos that I would lose. I have an external hard drive for b/u.
So in iphoto the photos are side by side and if you open each one they are all of the same quality. If there is another or better way to open them then clicking on the photo I am not aware of it.
When I still had apple support they told me I had to delete them individually.
Then I accidentally duped all the photos because I misunderstood make a copy.