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Tyler Black, MD

Feb 12 • 12 tweets • 6 min read

The Rosette Nebula (Caldwell 49); captured in Hydrogen alpha-Oxygen3-Oxygen3 detail, and full colour stars.

This nebula is 65 light years across and about 5,000 light years away.

#Astrophotography

Thread: how do I do this?!

/1

I have taken a picture of this before... it was one of my best taken from my DSLR + simple star tracker setup.
However, you can see that the detail with the telescope+guided mount is much sharper.

With hydrogen & oxygen filters, I can separate the data cleanly, too.

/2

Incredibly, the photo is taken from my balcony in Vancouver, where there is a tremendous amount of light pollution, AND it was taken pretty much directly pointing at a 3/4 moon. It was not a DARK sky at all.

/3

@antlia_filter

But, it's an incredible application of physics and science. The photons from the nebula are there, but they are in specific wavelengths of light. I purchased a filter that very narrowly allows those wavelengths through. @antlia_filter

/4

Each five minute photo i take lets through an incredibly faint amount of data. In fact, this is what 1 five minute exposure looks like:

if you look very closely, you can faintly see some stars.

/5

However, there is data there! in the darkest areas of the picture, the camera is receiving photons of light. if we streeeettttttchhhhh the data as far as we can (exaggerated here for effect), there is a signal in the noise!!

/6

By "stacking" (repeating this signal>noise and adding the images together), what happens is that the random noise stays random, but the faint signal stays a signal, so the computer can start working out what is noise and what is signal even better!

/7

When I get this image I have incredible processing tools (Pixinsight, Photoshop), that allow me to remove the colour cast (this is because of the moonlight and the filter itself).

/8

From this point, its just a ton of practice and technique! I separate the colour layers so that i can work on Hydrogen alpha and Oxygen III data separately (with stars removed using machine learning!)

/9

There are many processes I use, but mostly it's bending the curves of light to boost signal while minimizing background (space) noise.

Voila!!! The final image is 6500x4000, more than enough for me to print!

total data: 3.5 hours. As I add more data, it will get better.

/10

@QHYCCD

My gear:

@QHYCCD 268C main camera, QHY5-III-178M guide camera
@SkyWatcherUSA EQ6-R-Pro Mount
@WilliamOptics M-G50RIII guide scope
@antlia_filter "golden" 5nm narrowband filter
@Microsoft surface pro 7 tablet

And yes i will accept sponsorships and free gear 😅😅 to test and try! I am not above begging - this hobby is not cheap!!!

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More from @tylerblack32

Tyler Black, MD

@tylerblack32

Feb 12

Study out of southern switzerland. Measures of depression, anxiety, and stress varied as the pandemic went on, but overall numbers not particuarly high compared to other reported numbers. they did increase, however.

Interesting conclusion:

"anxiety and stress almost doubled over ten months following the end of the first pandemic wave. However... psychological distress may not be worse compared with pre-pandemic, and may in fact be less marked than in neighbouring countries in Europe."

super important, people who had chronic diseases far more impacted than those without.

Read 7 tweets

Tyler Black, MD

@tylerblack32

Feb 12

Reviewing a PUBLISHED PEER REVIEWED paper about anxiety prevalence during the pandemic in the UK, and the authors commented that because this funnel plot is symmetrical, publication bias is unlikely.

NONE OF THE STUDIES ARE IN THE FUNNEL!!!!!

Funnel plots are supposed to give you confidence that the estimate is not biased. Usually, it's to "show you if there is a bias around the mean."

In this case, the funnel plot serves to tell us to simply throw out the effect size.

As the error gets smaller, the certainty range is supposed to get smaller, that's the entire point of the funnel plot.

This is simply a metaanalysis of randomness.

Read 8 tweets

Tyler Black, MD

@tylerblack32

Feb 12

I really don't miss the hubris of old doctors who love to wax poetic about how great things were before modern ideas took over. It could be about some new technology or theory or idea. But it always goes back to "it was worse than we were before".

I dislike it so much.

/1

First, there are few things in healthcare that were better 100 years ago. Mortality rates were higher, life expectancy of his lower, outcomes were much worse, and treatments much more inhumane.

/2

Second, in almost always centers especially in the West around whiteness and ableism. There may be some who found it better earlier, but I promise you there are many groups who would never go back in time if given the chance.

/3

Read 9 tweets

Tyler Black, MD

@tylerblack32

Feb 11

Mental health note:

Fear is not unhealthy. It saves you from bears and car crashes and deadly viruses. Reasonable fears respond to distress.

Unreasonable fear is unhealthy. It preoccupies you with unhelpful thoughts that are exaggerated. Unreasonable fears only add distress.

It is unreasonable to fear masking occasionally as a cause of childhood developmental delay.

It is unreasonable (at this point) to fear COVID vaccination due to side effects or inefficacy.

It is unreasonable (with our current data) to fear that measures have caused suicide.

It is unreasonable to fear that masking can cause hypoxia or infection.

It is unreasonable to fear vaccinated people shedding virus or mutating virus.

Read 5 tweets

Tyler Black, MD

@tylerblack32

Feb 11

Bizarre new trend: painting fears about the virus (thousands of deaths daily, approaching 1M us deaths, no current end in sight, vaccine effectiveness but waning over time) as "unreasonable" and "unsustainable."

What a weird form of gaslighting.

I totally agree with tamping down the 🚨alert🚨 style messaging, but it's not "fearmongering" to acknowledge the real thing to be fearful of.

As far as I know, a virus killing thousands per day, mutating, and creating problems for our vaccines while much of the world still not vaccinated is kinda fearful.

Isn't it smarter to acknowledge the fear about the real thing and do realistic things to impede that thing?

Read 5 tweets

Tyler Black, MD

@tylerblack32

Feb 10

@QdQwerty

Thrilled to announce that with @QdQwerty and colleagues, we have published very timely description of pre-pandemic mental health. Congratulations to Dr. Alison Lee for the hard work on the publication, and proud to be a part of it.

Let's take a look!

academic.oup.com/pch/advance-ar…

/1

In this study, we took a look at the types of mental health presentations for kids over a 3y period. We used the HEARTSMAP, a reliable tool for helping emergency departments document psychosocial assessments and help with treatment planning.

jpeds.com/article/S0022-…

/2

In total, we looked at the HEARTSMAP data for 1,530 kids.

Broken down by the HEARTSMAP domains:

PSYCHIATRIC: 40% with severe concerns
SOCIAL: 27% moderate/severe concerns
YOUTH HEALTH: 22% moderate/severe concerns

/3

Read 8 tweets

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