DSLR camera adaptor for Omni Plosl 32mm eyepiece?

[jamesj01]

Hi everyone,

recently just purchased a 32mm Omni Plosl 1 1/4 inch eyepiece - https://www.harrisontelescopes.co.uk/acatalog/celestron-omni-plossl-32mm-eyepiece.html. However, it does not fit into my camera - to - telescope adaptor piece due to the body of the eyepiece being to wide. Are there any adaptors i can purchase for this eyepiece? 

Edited June 3, 2020 by jamesj01

[PeterCPC]

Would this fit?

Peter

[John]

The Meade 4000 plossls are the best for those adapters - they are slimmer than most plossl eyepieces.

 

[jamesj01]

@PeterCPC @John My eyepiece is around 40mm wide - will this fit this adaptor then?

[Alien 13]

I have to ask why are you using an eyepiece rather than prime focus or a Barlow lens, both offer better image quality?

Alan

[jamesj01]

@Alien 13 sorry i am new to this all - is it better to use a barlow lens or prime focuser instead of an eyepiece when taking photos of DSOs?

[Louis D]

14 minutes ago, jamesj01 said:

@Alien 13 sorry i am new to this all - is it better to use a barlow lens or prime focuser instead of an eyepiece when taking photos of DSOs?

Yes, as long as you can reach focus with prime focus.  Reaching focus won't be an issue for Barlow projection.

[jamesj01]

28 minutes ago, Louis D said:

Yes, as long as you can reach focus with prime focus.  Reaching focus won't be an issue for Barlow projection.

okay brilliant so to do this i juts focus the telescope as i would normally with the barlow lense attached?

[Louis D]

49 minutes ago, jamesj01 said:

okay brilliant so to do this i juts focus the telescope as i would normally with the barlow lense attached?

Yes.  I don't know what type of camera you have.  If it's a DSLR, you'll need a 1.25" to T-mount adapter that fits in the Barlow in place of an eyepiece and a T-ring for your particular camera's mount that screws onto the other end of the adapter and then attaches to your camera mount's opening on its other end.  If your Barlow already has a T-thread around the top, you can skip the adapter and just attach the T-ring directly.

Thus, the T to 1.25" adapter shown above could have Barlow optics in it already.

Edited June 3, 2020 by Louis D

[jamesj01]

@Louis D thanks for the really good picture this helps alot. Would you recommend a Barlow then instead of a 32mm eyepiece for DSO photography? 

[Louis D]

I can't help you there as I don't do DSO photography.  All I can say is that Barlows are generally used to increase magnification for solar system imaging where there is plenty of light.  DSO imaging is mostly about getting the most photons from dim objects in the shortest amount of time to keep exposure times shorter and image noise at bay.  Adding magnification without increasing aperture sort of defeats this goal.

[Alien 13]

The best option for DSO imaging is prime focus however some scopes especially reflectors do not have enough inward focus travel to achieve this with a DSLR, the fix is to shift the primary mirror further up the tube which can work if the distance is small or use a barlow lens to move the focus point further out.

In my opinion a barlow lens works far better than an eyepiece for this but you do end up making the scope much slower, fine for Luna and Planetary imaging but not ideal for DSO but in some cases its the only option unless you just use the camera and a lens on its own.

Alan

[jamesj01]

@Louis D ok many thanks for you help 

[jamesj01]

5 hours ago, Alien 13 said:

The best option for DSO imaging is prime focus however some scopes especially reflectors do not have enough inward focus travel to achieve this with a DSLR, the fix is to shift the primary mirror further up the tube which can work if the distance is small or use a barlow lens to move the focus point further out.

In my opinion a barlow lens works far better than an eyepiece for this but you do end up making the scope much slower, fine for Luna and Planetary imaging but not ideal for DSO but in some cases its the only option unless you just use the camera and a lens on its own.

Alan

Brilliant thanks - when using a barlow to DSLR i take the extension tube of the adapter right?

[Alien 13]

1 minute ago, jamesj01 said:

Brilliant thanks - when using a barlow to DSLR i take the extension tube of the adapter right?

It depends, some barlow lenses come with a built in T thread so you can connect directly but any extension has the effect of increasing the barlow lens "magnification factor" so a X2 can become a X3 which is sometimes useful for certain targets. For DSO imaging you want to keep the distance between the lens and camera as short as possible.

Alan

[Louis D]

I have limited in focus with my Newtonian, and I can achieve DSLR prime focus by screwing the optics section of my GSO/Revelation coma corrector (with a 25mm spacer ring) directly into the T-ring via an M48 to T-thread adapter.  It works as a weak Barlow at 1.10x to extend focus and also flattens the field while correcting coma.  I used it to take this photo of the 2016 Mercury solar transit.

Edited June 4, 2020 by Louis D

[jamesj01]

14 hours ago, Alien 13 said:

It depends, some barlow lenses come with a built in T thread so you can connect directly but any extension has the effect of increasing the barlow lens "magnification factor" so a X2 can become a X3 which is sometimes useful for certain targets. For DSO imaging you want to keep the distance between the lens and camera as short as possible.

Alan

ok many thanks for you support  

[jamesj01]

12 hours ago, Louis D said:

I have limited in focus with my Newtonian, and I can achieve DSLR prime focus by screwing the optics section of my GSO/Revelation coma corrector (with a 25mm spacer ring) directly into the T-ring via an M48 to T-thread adapter.  It works as a weak Barlow at 1.10x to extend focus and also flattens the field while correcting coma.  I used it to take this photo of the 2016 Mercury solar transit.

nice photo aswell and cheers for the help  

[johnturley]

On 03/06/2020 at 21:39, Alien 13 said:

I have to ask why are you using an eyepiece rather than prime focus or a Barlow lens, both offer better image quality?

Alan

Prime focus gives too small an image scale for planets and close up lunar shots

John

[jamesj01]

On 05/06/2020 at 11:10, johnturley said:

Prime focus gives too small an image scale for planets and close up lunar shots

John

many thanks