Free Astronomy Tools Website

[Pete Presland]

what a great resource, well done to all involved!

[Earl]

only just seen this post, what a fantastic resource. Thnk you FLO

[RobertI]

You guys continue to impress! I can see this developing in to the 'one stop shop' for imaging and observing preparation.

[RT65CB-SWL]

Great resource tool guys (and girls)! Please can we have it as a 'sticky' somewhere? Thank you.

[FLO]

Thank-you for the kind comments

We have another update for the astronomy tools binocular calculator section.

Manufacturers tend to specify a binocular's FOV either as metres @1000 metres or angular FOV in degrees, but rarely both. This can make comparing binoculars difficult so we have created calculators to convert one format to another. 

Hope you find them useful. 

Steve

[avtaram]

Thats really useful, thanks.

Avtar

[Grant_FLO]

Minor update to Astronomy Tools - cameras now store the pixel size horizontally and vertically. Whilst the majority of cameras have square pixels, there are some that don't.

As a result, we have now added the Lodestar, Lodestar Colour and Lodestar X2's to the FOV simulator and added them to our site:

Lodestar

Lodestar Colour

Lodestar X2

I need to check if the Lodestar X2 Colour has the same pixel size as the regular X2 mono version and if it is, I will add that as well.

Cheers,

Grant

[Grant_FLO]

It's also worth a reminder - if there are any other useful tools or calculators you use that you would like to see on the astronomy.tools website, please let us know and we would be happy to look into adding them.

Thanks,

Grant

[Andrew W]

Been using the fov bit. very helpful  TA!

[Grant_FLO]

We've added a couple of additional calculators to the binocular page - these let you calculate the apparent field of view from the magnification and angular field of view, using the conventional (simple) formula and the new ISO 14132-1:2002 Standard:

http://astronomy.tools/calculators/binoculars

[FLO]

Thank-you to everyone who has added telescopes, cameras and eyepieces to the Astronomy Tools website 

Also, we would like the site to be as useful as possible so we really won't mind if you enter equipment sold by our competitors 

Steve 

[FLO]

With the telescope, camera and binocular lists growing we have added search-as-you-type ability to the drop-down lists

It is certainly a lot quicker than multiple menus or scrolling through a long list. 

As always, if you can see a way Astronomy Tools can be improved or would like a new calculator added please let us know. 

HTH, 

Steve 

[Kriss Craik]

I like it, thanks for putting the work in

[FLO]

We have added a new CCD Suitability calculator to the Astronomy Tools website  

[Tristan]

CCD Calc is very useful. Thank you.

[FLO]

We've added a new calculator to help determine where in your optical train any dust bunnies or reflections are coming from:

http://astronomy.tools/calculators/dust_reflection_calculator

This also has a handy feature that if you don't know the size in pixels of the dust shadow / reflection you can choose a jpg image and measure on the screen the size in pixels by clicking / dragging over the image.

[Tim]

On 26/03/2021 at 14:23, FLO said:

We've added a new calculator to help determine where in your optical train any dust bunnies or reflections are coming from:

http://astronomy.tools/calculators/dust_reflection_calculator

This also has a handy feature that if you don't know the size in pixels of the dust shadow / reflection you can choose a jpg image and measure on the screen the size in pixels by clicking / dragging over the image.

That's brilliant, just used it to check on a known reflection source in a rig I was testing, and it performed brilliantly. Thank you

[Vulisha]

Ooohh so you are the guilty ones for this brilliant website Thanks FLO! 

[vlaiv]

How does it work on reflections?

In order for unfocused light to reach the sensor - you need two reflections - one reflecting light back and another reflecting it again towards the sensor.

Using size of reflection on sensor can only give you total additional light travel but it can't tell you how far away reflection surfaces are.

[RT65CB-SWL]

@FLO - TeleVue Panoptic & Radian e/p's showing up in 'Choose Equipment --> Telescope:' field! - (see below)

 

[FLO]

13 hours ago, Tim said:

That's brilliant, just used it to check on a known reflection source in a rig I was testing, and it performed brilliantly. Thank you

Excellent 🙂

13 hours ago, Vulisha said:

Ooohh so you are the guilty ones for this brilliant website Thanks FLO! 

Yes - guilty, we don't make much mention of FLO on the astronomy.tools website but it is another of our projects.

13 hours ago, vlaiv said:

How does it work on reflections?

In order for unfocused light to reach the sensor - you need two reflections - one reflecting light back and another reflecting it again towards the sensor.

Using size of reflection on sensor can only give you total additional light travel but it can't tell you how far away reflection surfaces are.

This method is only really useful for things in the direct optical train - e.g. in your filters, flatteners etc.. but wouldn't anything further back then that be so out of focus it's not going to show much on your sensor chip if at all?

 

1 hour ago, Philip R said:

@FLO - TeleVue Panoptic & Radian e/p's showing up in 'Choose Equipment --> Telescope:' field! - (see below)

 

Fixed

 

[vlaiv]

6 minutes ago, FLO said:

This method is only really useful for things in the direct optical train - e.g. in your filters, flatteners etc.. but wouldn't anything further back then that be so out of focus it's not going to show much on your sensor chip if at all?

Yes, I understand that, but suppose you have sensor with sensor cover window, chamber window, filter and field flattener.

All of those are reflective surfaces and all of those are fairly close to each other. Which two produced the reflection?

[Grant]

3 hours ago, vlaiv said:

Yes, I understand that, but suppose you have sensor with sensor cover window, chamber window, filter and field flattener.

All of those are reflective surfaces and all of those are fairly close to each other. Which two produced the reflection?

Your only going to see the last reflection back to the sensor with this formula. I can't see a way to go further than that without knowing more about the placement of the other optical elements in the train - that can often be enough though to start diagonosing the issue.

This method is more useful / commonly used for finding dust motes though.

If you know of a different method though, I'm up for having a go at building a calculator for it.

[vlaiv]

27 minutes ago, Grant said:

Your only going to see the last reflection back to the sensor with this formula. I can't see a way to go further than that without knowing more about the placement of the other optical elements in the train - that can often be enough though to start diagonosing the issue.

This method is more useful / commonly used for finding dust motes though.

If you know of a different method though, I'm up for having a go at building a calculator for it.

I agree that this method is useful for dust shadows only and not particularly useful for reflections.

It can be modified to be useful for reflections as well - but I suspect that needed data is not going to be available to most people - or they can get confused about it.

If we knew exact positions of all elements - we could do a brute force search to find which two would provide exact distance, but I don't think that people will know needed distances.