I am wondering what experienced users consider appropriate/best pixel ( PPI ) dimensions for big prints ( 30 inches long dimension ) and small prints ( 11 inch long dimension ) ? Also the best PPI for monitor only viewing ?

And, don't forget - you may need some one or something along with you to help CARRY it !

Regarding this long zoom debate, I am a long time Canon shooter. I looked at the 100-400L - I have seen some GREAT images from it, but it is big and awkward especially at 400 and pumps air when zooming. Ken Rockwell claims the latest 70-200 F2.8 L IS III is the sharpest zoom on the planet - sharper than the my 70-200 F4 L - which is hard to imagine ! Anyway, the older 80-200 F2.8L or the newer ones are ALL very sharp and with a 2X converter equal the range and F stop of the 100-400 in a smaller more ergonomic package. I wanted the F2.8 aperture so I just got the older 80-200 ($800) and am now testing it with Tamron SP 2X converter - so far, I'm LIKING it !

For you birders out there, attached an image I took yesterday with Sigma 300mm F4 APO tele macro wide open and Tamron 2X on tripod. This lens is long discontinued but has been rumored to be as good as the Canon L - I agree ! Due to chip incompatibility with late Canon bodies, I cannot stop the aperture down from F4 - so I shoot it wide open all the time - which is what I want to do anyway !

It's more a matter of working with your particular lens, because some extenders have protrusions that mechanically interfere with the rear elements of the lens. Tamron extenders do not have this problem.

I agree with gessman's comment - Having said that, Ken Rockwell who has tried and used the Canon and Nikon stuff loves the TOKINA 11-16mm F2.8.

I would suggest an 85-100mm fast lens F2-2.8. I also would suggest that you MANUALLY focus to get the exact plane that you want in focus rather than relying on auto focus to give you what IT wants ! You will need good available light in your studio and the fast lens to facilitate your precise focusing.

I, along with Ken Rockwell and Peter Lik believe that shooting Fuji Velvia with proper scanning can yield superior results to current digital. That said, telephoto sports and nature work with Velvia requires the fastest multithousand dollar lenses 300 f2.8, 400 f2.8 - well you get the picture - which is impractical for most of us ! Shooting film with wide to normal angle lenses is a little more attractive/practical. I am a Canon digital shooter for longer telephoto work. And for medium telephoto I try to use a Pentax 645N with 180mm F2.8 and 300mm f4 Carl Zeiss lenses for the Pentacon 6X6 with adapter ( the Pentax lenses are great too). For serious wide angle work, I try to use a home made camera that I made from a Russian 6X9 Moskva 5 and a Mamiya Press 50mm F6.3 lens ( equivilent to 21mm ) - see photo attached. The 56X85mm film image is easily cropped to panoramic formats. The nearest E6 processing for me is 50 miles away !

P.S. You could also use the Korean 500mm F6.3 manual focus mirror lens - I have used one . They are only OK if you use a lens hood and good post processing. Still, nothing to brag about.

Yes, good observation - Canon =digital .... Pentax = film !

I am a Canon shooter - I use the 300mm F4 Sigma APO tele-macro with 2X or the Sigma 400mm f5.6 APO by itself. Both these lenses are great but long discontinued and scarce - but you could get lucky on e-Bay where they are $250-350. If you need the motor in the lens you will need the newest high priced stuff ( for Nikon )! The 300mm with 2X - you lose autofocus - the 400mm 5.6 gives you autofocus.

If you do not have IS you do NOT necessarily need a tripod - I use a monopod for 90% of my work which includes 400mm prime lens - see below

Yes, Ken Rockwell says the Canon S90 and 100 are the world's best P&S right now - See his reviews at kenrockwell.com .

If you are serious, and if you have not been there yet, go to kenrockwell.com - ALL your questions will be answered without bias ! Canon took away the pro market from Nikon in the 1980's - and for good reason ! Especially of late, Nikon has been making up ground in some isolated specific areas - albeit at higher costs ! If you are looking to ever get used lenses - Canon has the advantage because ot their greater proliferation.

Ken Rockwell ( kenrockwell.com )Swears by the Tokina 11-16mm - says it is sharper than the Nikon 12-24 ! See his review.