johnfosteruk

Perfect Steve!

The full discs are stunning!

A very appealing scene this evening. Oh, and a handful of stars in Cetus.

One frame, shot at 150mm with the Tamron 150-600 on a Nikon D7100. 1s exposure, F5, ISO 1000. Just a little fettling in photoshop to adjust contrast.

2 minutes ago, Peter Drew said:

Yet more sad news to start the New Year off with.  John was a core member of the SGL "family" and as such much missed by all at SGL.  Purchasing solar components from him kick started my solar interest for which I will be eternally grateful.  Sincere condolences to all concerned.

He didn't kick start anything for me, but It was his purchase, and subsequent review of the Lacerta Herschel wedge that led me to purchase the same and start taking the solar business more seriously. 

There must be so many SGL members with a similar debt of gratitude.

Very sad news indeed. John was an influential and knowledgable member of SGL. As others have said I did wonder why he'd not posted for some time.

RIP John.

8 minutes ago, DaveL59 said:

For astro tho perhaps consider a Nikon prime in the 135mm range.

Funny you should say that, I was going to mention the 135mm M42 SMC Super Takumar F3.5. It can be adjusted to focus to infinity, fairly easily and is a good little performer for astro. A lot cheaper than a Nikon too.

28 minutes ago, DaveL59 said:

I guess the answer would depend on what you want to do with it and budget.

If you fancy wildlife then the Tamron 170-600mm is decent, go after a mk/v2 model tho as that one's better than the original v1. Just check that it focuses OK across the zoom range (AF that is). Not cheap, usually >£500. If you want to see what it's capable of there's many shots in the photography section from folks like @johnfosteruk and others.

If you just want a reasonable all-in-one, the Tamron 16-300 is also good if yours is an APS-C sensor. I have both but on Sony-A mount.

Can't say much on Nikon glass as I've never used those but I'm sure others will be along to advise.

I was going to say it depends on whether you want something long or something wide. Which is why I'm now possibly going to second the 16-300 suggestion as it covers both ends. Never used it myself tho so can't speak for IQ, AF speed etc although DPReview say good things, although they say corner sharpness and AF reliability suffers at the long end (worth looking at other reviews though as that may not be the case on every unit).

They also say there's CA and distortion in spades but Photoshop etc can sort that if you have it.

If you're wanting it for Astro work though, all of that will cause you problems.

41 minutes ago, StuartT said:

Here is my go at some of the JWST data (downloaded from the MAST portal). This is a comb of six filters from the NIRCAM. I used pixel math to map the filters (roughly) to the RGB channels as follows

R: 2*f470n + f444w
G: f335m + 2*f200w
B: f187n + 2*f090w

 

That's nice.

I downloaded the Stephan's Quintet data last night - nice big files aren't they.  I'll be having a play with them tonight.

17 minutes ago, DaveS said:

 

Been waiting for this, cheers Dave.

16 minutes ago, StuartT said:

It looks like to download the data from MAST you need to be a university employee (registration asks for an institution and a job title). Any other way of getting it?

 

https://archive.stsci.edu/contents/newsletters/july-2022/accessing-jwst-science-data-after-the-end-of-commissioning

You can still register - just use N/A for those fields.

16 minutes ago, Laurieast said:

Only explanation I have seen is this, from:
https://webbtelescope.org/contents/media/images/2022/038/01G7JGTH21B5GN9VCYAHBXKSD1
 

 

Color Info

These images are a composite of separate exposures acquired by the James Webb Space Telescope using the NIRCam instrument. Several filters were used to sample broad wavelength ranges. The color results from assigning different hues (colors) to each monochromatic (grayscale) image associated with an individual filter. In this case, the assigned colors are:   Red: F444W Orange: F356W  Green: F200W + F277W Blue: F090W + F150W

Compass Image

Here's a lot more detail on the NIRCam filters:

https://jwst-docs.stsci.edu/jwst-near-infrared-camera/nircam-instrumentation/nircam-filters

As others have said, just in this release there's so much to enjoy. Looking forward to regular releases. And don't forget you can access the data yourself via MAST, as described here:

https://archive.stsci.edu/contents/newsletters/july-2022/accessing-jwst-science-data-after-the-end-of-commissioning?filterPage=news&filterName=news-filter

4 minutes ago, raadoo said:

@johnfosteruk Really good shout, there. Getting detailed spectra on exoplanets means we're far more likely to find Earth-like planets. Though, personally, I'm more interested in the weirdos; you know, the ones where it rains diamonds or there's never ending storms, the kind that make sci-fi seem tame by comparison.

Yes, me too, it'll be great to see some of that stuff confirmed, and new things too.

7 minutes ago, tomato said:

I love the diffraction patterns on the bright stars in the final image, a nice JWST signature.

Very nice, here's a rough approximation of the strut/secondary layout someone 'knocked up' and resultant Fourier transform that I found 6 years ago just for interest. Not far off the final result.

Let's not forget another area Webb will be contributing to - exoplanets.

Terrific images Neil.

Awesome!

Hi, my name's John and it's been approximately 3 years since I handled a Herschel wedge.

I've had the occasional visual session with Baader film but I thought that what with Sol perking up a bit, it was about time I fired up the imaging setup. My intent was to do it first thing but other tasks required my time and I didn't get to it until just after 17:00 so the seeing wasn't good. 

Nonetheless I managed to wrestle some detail out of a stack of the best 25 frames out of 100. It took a bit of selective processing in PS and rescaling to approx 25% of the original image scale tho. This current group is quite the spectacle isn't it.

Usual process - Pipp>Autostakkert>IMPPG>Repeat with different settings several times, and blend the best bits with some masks and a bit of additional sharpening/contrast & levels adjustment in PS. It appears I need to capture some flats as well.

This feels like a good start to getting back on the solar imaging horse again, I'll see if I can add in a barlow next time and I may even start looking at Ha options soon.

Mono

RGB

Stunning image Avani. 

1 hour ago, ScouseSpaceCadet said:

Earlier I took the missus in the garden to look at a smashing crescent 🌒. Then back out again at 8:30pm for the CPRE star count (12), and again at 9pm for a quick look with the 15x70s at M42 and M45.

I'm off to get some extra layers on and set up the 4" and AVX for a long night. Probably a frustrating night because against my better judgement I won't be able to resist having a crack at the Leo Triplet and Markarian's Chain. ...

Cracking crescent wasn't it. Grabbed a few snaps.

Then some doubles in Orion, starting with the Trapezium, good seeing gave up A-D easily.

Just now, neil phillips said:

But enough to extract a bit more detail and contrast perhaps ?

Definitely a little, marginal gains and all that, every little helps.

Nice image. Lovely depth to it, makes you want to fly through NGC 1893.

I setup the Skymax last night at about 20:30 and ended up not observing a single thing with it. My neighbour and our daughter popped out and we spent about an hour setting the world to rights, then it was dinner time. That crescent moon, with the earthshine was stunning with the naked eye tho.

Fine images. You can't beat a Herschel wedge I say, unless your intent is to keep the setup cheap

Lovely image. I quite like the hue but if you really wanted to neutralise it you could use the eyedropper tool (assuming GIMP works the same as PS) to read the RGB values on the background sky, then adjust your RGB levels accordingly to balance it all up.