Super cheap 500mm f8.0 telephoto lense

[Bennet0602]

I've seen a lot of 500mm telephoto lenses on ebay for as low as 35 euros and im wondering if the can be used for some beginner astrophotography?

The only obvious issue with these is the aperature of 8.0 but could they be used for brighter deep-sky objects if you use a tracker and longer exposures? 

[Cumbrianwolf]

37 minutes ago, Bennet0602 said:

I've seen a lot of 500mm telephoto lenses on ebay for as low as 35 euros and im wondering if the can be used for some beginner astrophotography?

The only obvious issue with these is the aperature of 8.0 but could they be used for brighter deep-sky objects if you use a tracker and longer exposures? 

Have you got a link or more details as to lots of 500 mm photo lenses, also what camera are you using it on? Another option is the mirror lenses, a bit of a task to manually focus but with a Bahtinov mask it can be done, and they used to work well for me back in the days of film.

[Bennet0602]

 

https://www.ebay-kleinanzeigen.de/s-anzeige/doerr-danubia-500mm-1-8-500-mm-canon-ef-kompatibel-neuwertig/1962752750-245-9663?utm_source=sharesheet&utm_medium=social&utm_campaign=socialbuttons&utm_content=app_android

 

Someting like this, there are a lot of these but from diffrent brands.

[TerryMcK]

You are probably wasting money on something like that. Best with a shorter focal length for DSOs and definitely not a zoom lens.

[Cumbrianwolf]

1 hour ago, Bennet0602 said:

 

https://www.ebay-kleinanzeigen.de/s-anzeige/doerr-danubia-500 mm-1-8-500-mm-canon-ef-kompatibel-neuwertig/1962752750-245-9663?utm_source=sharesheet&utm_medium=social&utm_campaign=socialbuttons&utm_content=app_android

 

Something like this, there are a lot of these but from different brands.

I agree with what Terry said, I have also had such lenses in the day, and they are rather bad to be honest, often narrow fields of view like looking through the cardboard tube from a kitchen towel roll and very hard to manually focus.

Edited December 20, 2021 by Cumbrianwolf
Better grammar.