New document: How to intelligently select a camera (preliminary cut)

[Richard Crisp]

this is work in progress. I keep getting asked questions by users as to what camera they should buy. Of course there's no single answer.

so I am preparing a monograph to examine the various factors involved in sensors and cameras appropriate for use in astro-imaging (and other imaging as well).

the first section of the work is in a pre-release form but may be useful for discussion so I am posting it here today.

The idea is to add to this work each week and to engage a round of questions if there are any

For those that don't know me, hence my qualifications to make such a work: I am a professional semiconductor industry design engineer, with over 30 years of practice. I have been astro-imaging for over 10 years and have developed the tricolor emission line (narrowband) technique now in wide practice, I also have pioneered the use of 6x7 format lenses for widefield astrophotography and have delved deeply into residual bulk image (RBI) phenomena and have published scientific papers (peer-reviewed SPIE papers) on the topic.

Even though I have pretty strong opinions as to what makes sense and doesn't when it comes to spending thousands of dollars for a camera, I am keeping this work neutral with respect to suppliers and only am focusing on the technology and tradeoffs for one approach versus another.

here's the work in progress in case anyone is interested:

http://www.narrowbandimaging.com/incoming/Camera_Selection_Criteria...

I plan to add more to the document in coming days

in the meantime I am available to answer questions that may arise.

I realize this is a very technical approach to the matter at hand, it is also a very technical hobby so it is hard to be thorough and avoid all of the technical detail.

[Richard Crisp]

it is on the list on the first page... cooling is most definitely an imporant topic and three of the main four makers in the US simply don't seem to get it.

[Greg Marshall]

Good point. Most people would assume that a "green" filter would not pass IR when, in fact, it is usually almost transparent to IR.

Another topic I hope you'll cover is the value of cooling and the efficiency of various cooling methods.

[Richard Crisp]

one other comment: several of these points were things I had to learn the hard way.... like the need for a NIR cut filter for OSC...

[Richard Crisp]

i might also add that wrt to OSC vs mono, many experienced people don't understand the sampling differences and the change in the optimal focal ratio for one versus the other.... I think everyone will find something in here that is useful...

[Richard Crisp]

it is about two days old and it just a first cut at the first 10-15% of what I plan to do...

I hear you and thanks for the input. I think the final product will be a lot better.

[Greg Marshall]

I never want to say that something is "too technical", but for a given audience it might be either too technical or not technical enough. That is, would someone that is sophisticated enough to appreciate the physics of photon penetration in a BSI sensor really have a need for or interest in pros and cons of mono vs OSC? Of course, putting them in separate chapters and adding a table of contents will help. Maybe I'm wrong - it's happened once or twice before!

[Richard Crisp]

Thanks for the comments. This is only the beginning of a much larger document. I'll get to read noise in another chapter that hasn't yet been written..... I am just testing the waters with the beginning materials that are focused solely on the sensor and pixel architecture.... if you look at the contents page I have only covered the RED stuff so far....

are you saying you think it is too technical or were you saying something else Greg?

[Greg Marshall]

Richard, this is very interesting and I learned some things from it, but also felt that the target audience level of technical ability and interest is too broad. The whole BSI discussion is fascinating, but seems pretty irrelevant to the question "what camera should I buy" for almost anyone. After covering the basics of mono vs OSC, pixel size, QE and spectral response, perhaps the next level would be read noise. In discussions I have observed that was where 90+% of people dropped out.

[Trevor Woodrow]

Great work as always, Crisp. So glad to have you here.

t