The back of this photo shows the signature of Col. John J. Cladek (1824-1884), as well as his writing of his identified regiment, being the 35th NJV. After reviewing his service periods, this would suggest the photo was taken between Aug. 15, '63 and Aug. 12, '65 ( more specifically, possibly at sometime in period during Aug./Sep./Oct., '63, before the regiment left NJ for Washington DC).
Col. Cladek m/i to the 35th NJV on Aug. 15, '63, for three years, but was dismissed prematurely on Aug. 12, '65. (see
https://historicalpubs.njstatelib.org/searchable_publications/civilwar/NJCWidx27/ @ page 1054).
Interestingly, the reasons for his early dismissal as regimental colonel might be worth investigating further - common reasons included incompetence, drunkenness, conduct unbecoming and insubordination. Apparently, Col. Cladek was dismissed from the service on Aug. 12, '65, for defrauding his men of pay due to them.