Why can't Webb take (suboptimal) photos as soon as it gets to L2?

> It will take the JWST team three months to very slowly and carefully align the 18 mirror segments. How slow? One of the telescope scientists described it to me this way: “the mirror segments move at the same rate that a blade of grass grows.” This delicate but time-consuming process brings the 18 separate images together to create one sharp image.

> The first round of focusing will be for just one instrument, the Near-Infrared Camera. Remember, though, that JWST has four separate instruments (more on that below), and they are not all looking at exactly the same point on the sky. The focusing process must then be repeated in what is called a “Multi-Instrument Multi-Field” (MIMF) sequence, which may be done more than once to achieve perfect focus for all the instruments.

> By the time JWST is four months out from launch, the telescope should be aligned, and all the instruments focused. After that, the JWST team turns its attention to the science instruments themselves.

From https://www.planetary.org/articles/jwst-first-images

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I can only assume (fyi I have no real idea what I’m talking about here) that since JWST is designed to see so far into space that trying to take a picture without aligning any of the instruments and while in transit would result in something more incoherent than just a suboptimal picture.

A large part of the wait is for the telescope to cool down, many of the instruments are likely to not function at all until they reach extremely cold temperatures. The other issue is that the complexity of the instruments means that without rigorous calibration any data gathered is likely to be completely useless noise. The calibration isn't as simple as turning a blurry image into a clear one.

Here's a whole list of calibration challenges that needs to be overcome: https://www.stsci.edu/~INS/2010CalWorkshop/mather.pdf

Directly to your point, it is also partly a management decision to only release finished results.

From JAN9 press conference panel notes by Marcia Smith (@SpcPlcyOnline):

>Jane Rigby: we want the first images the public sees to be "wow" images that do justice to what these four instruments can do. So we will wait till commissioning is complete and we're starting normal science operations.

https://twitter.com/SpcPlcyOnline/status/1479910940988649474

AFAIK it is possible we'll see some images released during the calibration process.

The individuals mirrors need to be adjust and that can take months