Astrophotography equipment and techniques and questions

[Jeff WX1USN]

Yes it has a Light Pollution filter built in that you can turn on or off, works best on Nebulas

 

[Levina de Ruijter]

Jeff, I have a question. You use the S30 and the S50. I know that the S30 has a wider view than the S50 so you get more objects in your image. But the actual distance to or size of the DSO won't change one bit of course. So when do you use one, when the other?

 

[Jeff WX1USN]

think of them in Canon Lens terms, the S30 is a 150mm and the S50 is a 250mm so the object will appear larger in the S50 and smaller in the S30. If I have a bird on my feeder that fills the frame with a 250mm lens then change to the 150mm the bird on the sensor is smaller, or the opposite bigger.

M45 the Pleadis will not fit in a S50 but does in the S30, same with the Andromeda M31

they are coming out with a new S30 and S50 with higher quality sensors! I will be waiting on the S50 one since I find the S30 sensor which is the same size as the one in the S50 is an updated sensor and has less noise than the S50's one. If it is significantly better sensor in the S50 I will buy the new one and sell or give the old one.

In Stellarium I created a lens/camera to show the FOV of each scope I can see if the object fits in the S50 then I use it, if it doesn't I use the S30. There are not that many objects that need the S30. You can also use mosaic mode in the S50 from 1.0 to 2.0x the FOV and at 2.0x it is the same as the S30 BUT it takes 3-4 times as long with many more dropped frames to capture the image.

 

[Levina de Ruijter]

M45 the Pleadis will not fit in a S50 but does in the S30, same with the Andromeda M31

Right. That’s clear.

Because I know how the principle works of course and with birds I know if a heron will fit in the frame of a certain lens at a certain distance, That’s not the case with stellar bodies however as I have no idea of scale. Maybe I should go for the S30 after all.

How much can you crop the files from a S30. How big are the files, how many mpx?

 

[Jeff WX1USN]

Right. That’s clear.

Because I know how the principle works of course and with birds I know if a heron will fit in the frame of a certain lens at a certain distance, That’s not the case with stellar bodies however as I have no idea of scale. Maybe I should go for the S30 after all.

How much can you crop the files from a S30. How big are the files, how many mpx?

Both the S30 and S50 have 2 mpx cameras so they are really limited in how much you can crop without getting severe pixelation. The objects are like taking a pic of a building from the only vantage point the object scale doesn't change you use different lenses to get the shot you want. the S30 is good for large scale objects while being poor for the vast majority of objects. Even the S50 is disappointing on things like the Ring Nebula as it is so small.

Check out various objects taken with my S30 and S50 on my flickr album where I have the same object taken with both scopes, you may have to poke around the album a bit. https://www.flickr.com/photos/jmpadell/albums/72177720314620443

 

[Levina de Ruijter]

Both the S30 and S50 have 2 mpx cameras so they are really limited in how much you can crop without getting severe pixelation. The objects are like taking a pic of a building from the only vantage point the object scale doesn't change you use different lenses to get the shot you want. the S30 is good for large scale objects while being poor for the vast majority of objects. Even the S50 is disappointing on things like the Ring Nebula as it is so small.

Check out various objects taken with my S30 and S50 on my flickr album where I have the same object taken with both scopes, you may have to poke around the album a bit. https://www.flickr.com/photos/jmpadell/albums/72177720314620443

Ah, yes 2 mpx is not a lot... Okay.

Thanks!

Will definitely check out your flickr album.

 

[Jeff WX1USN]

I have added more images from both my S50 and S30 to my flickr album and started a separate album for the S30. So far I have done all my imaging from my light polluted home 300 feet from a major mall and 600 feet from a 24 hour factory. It is Bortle 7.5-8. Bortle is a system for telling how much light pollution your area has. My area is what is known as a transition zone, a cross between suburban and city skies. On dark nights I cannot see the milky way and can't see most constellations only the brighter stars.
Both the Seestar scopes do very well in light polluted areas.
There are dozens of youtube videos and several facebook sites for the Seestar scopes.

Here are my two albums

S50/S30 https://www.flickr.com/photos/jmpadell/albums/72177720314620443

S30 https://www.flickr.com/photos/jmpadell/albums/72177720323580754

As I told Levina my recommendation for you first scope should be the S50 as there are many more smaller targets than there are large targets. almost all galaxies and globular clusters are small even in the S50.

 

[Levina de Ruijter]

I have added more images from both my S50 and S30 to my flickr album and started a separate album for the S30. So far I have done all my imaging from my light polluted home 300 feet from a major mall and 600 feet from a 24 hour factory. It is Bortle 7.5-8. Bortle is a system for telling how much light pollution your area has. My area is what is known as a transition zone, a cross between suburban and city skies. On dark nights I cannot see the milky way and can't see most constellations only the brighter stars.
Both the Seestar scopes do very well in light polluted areas.
There are dozens of youtube videos and several facebook sites for the Seestar scopes.

Here are my two albums

S50/S30 https://www.flickr.com/photos/jmpadell/albums/72177720314620443

S30 https://www.flickr.com/photos/jmpadell/albums/72177720323580754

As I told Levina my recommendation for you first scope should be the S50 as there are many more smaller targets than there are large targets. almost all galaxies and globular clusters are small even in the S50.

Very helpful, Jeff. Thanks.

Any news on the new versions of the Seestar, when those can be expected?

 

[Jeff WX1USN]

Just rumors from the CEO of ZWO so far. I will be interested to see what they do, will it be the same size sensor so the same FOV or a bigger sensor so a smaller FOV.

They said "bigger better sensor" so depends on what that means. The S30 has a slightly better sensor than the S50, it is the same size but it is the upgraded version of it.

 

[Jeff WX1USN]

Here is an example of the difference between the two sensors. The S50 is an older sensor so has slightly more noise, the S30 is an upgraded sensor, they are both still 2 mpx and same size and pixel density but the S30 is an upgraded sensor and it is noticeable in the noise in the fits image. You can overcome the noise with longer, i.e. more, exposures but it is nice to have a good sensor to begin with. SO when they say bigger and better, we will see what they do and when.

Here are two images, the S30 is on the left and the S50 on the right. they were not taken on the same night but they were taken about the same time with the same sky conditions. You can see first that the S50 has a bigger image size (they are both M31 the Andromeda Galaxy) the galaxy is bigger and the stars are bigger than in the S30 image, but you can also see there is more noise in the S50.