ASI290MM Mini camera integrates the Sony IMX290 1/3″ sensor (5.6 mm x 3.2 mm). It is ZWO's first mini camera. This camera has 1936 x 1096 pixels. The pixel size is 2.9 μm x 2.9 μm. This camera provides 12bit ADC and its QE peak is over 80%.
The ASI290 mini camera offers very good performance for planetary imaging and guiding. Low read noise, high dynamic range, QE peak >80%, AR protective window and much more.
Relative QE Curve, estimated Peak Value of about 80%.
290Mini vs. 290MM
Compared with the ASI290MM camera, the 290mini has a smaller outlook, lighter weight, and can reach focus at the same position as the eyepiece.
USB2.0Port & ST4 Port
USB 2.0 Port: The Mini camera has one USB2.0 type C port. The Type C port is very popular in mobile phones, as it will not mind about the positive side/negative side of the adapter.
ST4 Port: Connect the mini camera directly to the auto guider port of the mount.
- M28.5-CS adapter
- CS-C adapter
- 1.25″ extender
- 1.25″ filter
The ASI174 and ASI290 mini cameras both have very beautiful outlooks, small size, lighter weight - but this is not the big deal.
We should consider much more…
How do we choose a good guide camera?
Many people may say: it must be small, suitable for use with different equipment (guide scope, OAG), and stable.
These are the basic demands for a good guide camera, and the ASI mini cameras fulfill them.
So, what else we do need?
The three most common requests: high sensitivity, precise guiding, big FOV.
Sensitivity is the first thing to consider. It is very important to look for a guide star. The 290 and 174 mono sensors have about 80% QE peak, can detect more stars in view. Also, can shorten the exposure time in guiding.
The ASI290 mini is designed for precise guiding. 2.9um pixel size can give you a higher arcsec/pixel than the 224 or 120 camera. This means that, in same guide scope, the 290 mini can detect slighter movement of stars. The ASI290 mini will improve about 30% guide precision over the 120mm.
The ASI174 mini is designed for Big FOV guiding. This is very useful for looking for a guide star with the OAG. When you use an OAG with a Ritchey-Chretien or Schmidt-Cassegrain telescope, the hardest part is looking for a guide star. The ASI174 mini has a 1/1.2″ sensor which means you have 4 times bigger FOV than the 120mm.
The back of the ASI mini camera is like a smiling face, its mouth being the Type C USB port, which is widely used in mobile phones. Its nose is the ST4 port, for guiding. Any time you use the mini camera, there will be a smiley face to keep you company in the dark night.
Focus Like an Eyepiece
The ASI mini camera can focus at same distance as an eyepiece. You can focus using an eyepiece, then put the ASI mini camera into the 1.25″ holder.
Works with OAG
The Mini camera is suitable for use with an OAG, as it has a much bigger focus range than normal ASI cameras. You'll never have to worry about your guide camera not focusing with your main camera.
Works with CS adapter and CS lens
Works with 1.25″ extender
Sensor: 1/2.8″ CMOS IMX290/IMX291
USB2.0 MAX FPS
More resolutions can be user defined