• S. Rimjaem, G. Asova, J.W. Bähr, H.-J. Grabosch, L. Hakobyan, M. Hänel, Ye. Ivanisenko, M.A. Khojoyan, G. Klemz, M. Krasilnikov, M. Mahgoub, M. Otevrel, B. Petrosyan, A. Shapovalov, R. Spesyvtsev, L. Staykov, F. Stephan
  DESY Zeuthen, Zeuthen
• S. Lederer
  DESY, Hamburg
• M.A. Nozdrin
  JINR, Dubna, Moscow Region
• B.D. O'Shea
  UCLA, Los Angeles, California
• D. Richter
  HZB, Berlin
• J. Rönsch-Schulenburg
  Uni HH, Hamburg

Transverse projected emittance optimization is one of the main research activities at the Photo Injector Test facility at DESY, Zeuthen site (PITZ). The emittance measurement program in the 2009 run period concentrated on projected emittance measurements using a single sit scan technique. The photocathode laser profile has been optimized yielding small emittance. The flat-top temporal profile has been used in the standard projected emittance measurements. The small emittance values down to less than 1 mm-mrad have been measured for the nominal 1 nC bunch charge. Emittance optimizations for lower bunch charges have also been conducted using the same measurement setup and procedure as for the case of 1 nC. Numerical simulations have been carried out to compare the results with the measurements. Measurement and simulation results of the transverse emittance for the bunch charges of 0.1, 0.25, 0.5 and 1 nC will be reported and discussed in this contribution.