The 400si is a compact SLR that's perfect for beginners, but gives you room to grow. Point and shoot simplicity is available through its expert program feature, which lets the user choose among sports,action, portrait, landscape, close up and night portrait exposure settings; more advanced users can select aperture or shutter priority and manual exposure settings as well.
A built in multimode flash with red eye reduction and autoexposure compensation can be supplemented with additional flash units that can be operated as wireless units. Other features include continuous film advance, a self timer and manual focus override.
| Autofocus | TTL Passive with predictive AF, Auto AF Mode Selection |
| Number of Focusing Points | 1 |
| AF Sensitivity | -1 to 18 |
| Shutter Speed | 30 to 1/2000 sec. |
| Maximum Flash Synchronization Speed | 1/90 |
| Film Loading | Automatic |
| Film Transport | Continuous drive at 1 fps. |
| Film Rewind | Automatic, into cassette |
| Metering System | 8-segment meter with Expert Programmed AE |
| Metering Sensitivity @ ISO 100 with f/1.4 | -1 to 18 |
| Exposure Compensation | +/-3EV |
| AE Lock | AE/AF |
| Exposure Modes | P, S, A, M Night, Portrait, Sports, Macro-CloseUp, Landscape Modes |
| Viewfinder Info | Flash OK Shutter Speed and Aperture Display Through-the-Lens (TTL) Viewing |
| Self Timer | Yes |
| Dimensions (WxHxD) | 57/8 x 35/8 x 25/8" (147 x 93 x 66mm) |
| Weight | 1 lb 10.4 oz with Sigma 28-105mm f/4-5.6 UC lens |