Tests with the ASI174MM of ZW Optical

Some tests with the ASI174MM.

Comparison with a Lumenera Lt225

Comparison with a Lumenera Lt225.

• Both cameras have a USB3.0 connection and sensors of similar width, but the ASI174 sensor is visibly higher, 7.1mm vs 6.0mm.
• Both cameras get warm during operation, the Lt225 somewhat more so due to its smaller body.
• The ASI174 would make it far easier to apply some external cooling such as a heatsink & fan due to the flat back of the housing with properly sized holes.
  The small body and puny holes of the Lt225 are a real problem here, even more in a mobile instrument where some mechanical wear might occurr.
• The cables of the ASI174 exit at the side, while the cables of the Lt225 exit at the back. This might be of importance in some instruments, eg. with short fork-arm mounts.
• The ASI174 has a T2-thread while the Lt225 has a C-Mount thread. Simple mechanical adapters should allow both to be used in the same environments.
• The ASI174 costs less than 40% of the Lt225!

Simple flats, taken as stack of 100 images

Contrast stretched center of a flat-field of the Lt225. The vertical and horizontal lines are clearly visible. Variation from 3.2 to 3.45 .

Contrast stretched center of a flat-field of the ASI174. Some horizontal pattern is visible. The cloudiness of the field is due to a not-so-uniform illumination. Variation from 12.5 to 12.9 , seems significantly smaller.

Changes in the flats with differing exposure times

Two flats were captured, one with 7ms, the other with 25ms. Then one flat was divided by the other. This should have removed all the stripes, but some remain, though of reduced amplitude. This is a real problem as it complicates the image processing to get a clean image.

Two flats were captured, one with 7ms, the other with 25ms. Then one flat was divided by the other. All the stripes are gone, THIS IS AVERY GOOD SIGN! The remaining cloudiness is due to non-uniform illumination.

More tests to follow with a better diffusor and a real target.