We present a color-magnitude (CM) diagram of M35, an open cluster. A DSLR camera was used for measuring the color index with the RGB channels. It is cost-effective and has relatively easy controls compared to astronomical CCDs for educational environments. The 8-inch refracting telescope was used at the Korea Science Academy of KAIST in Busan. The B-G color index was obtained from observations and the magnitudes from publications in order to draw CM diagram. The linear correlation of B-G to B-V is found. The RGB channel of the DSLR camera can be easily represented on the CM diagram for astronomical education with aid of easy controls.

We study near-infrared properties of the old open cluster King 11, based on the 2MASS photometric data. We determine the location of the red giant clump(RGC) in the (K, J - K) colo-magnitude diagram and derive the distance modulus of King 11 to be (m-M)0 = $12.50 ± 0.10 using the mean K magnitude of RGC. From the red giant branch slope - [Fe/H] relation we obtain the metallicity of this cluster, [Fe/H]=-0.17±0.07. The age and interstellar reddening of this cluster are estimated to be log t = 9.48±0.05, E(B-V)=0.90±0.03, by applying Padova isochrone fits to the data.