Topics

locked No stars on DLSR #Off-Topic


Paul Meesters
 

Hi,
last night I finally got round to using my Explore Scientific refractor (FCD100 - 10207 - CF) for the first time, mounted on the Exos2.

I have a field-flattener attached, and a T2 adaptor for my Sony A7iii. Whatever I do with the focusing in-or-out, I never get any stars in the display of my camera. 
It's not for using wrong camerasettings. I used a 15 seconds shuttertime at 32000  ISO.. no stars at all (and no, I did not forget the lens cap)

I'm not sure what I need to do to get a picture.. Do I need more extender tubes ? It's already sticking out more then I like, since the T2 adapter and the field flattener are very big...



Any advise is appreciated :)

Greetz
Paul


 

Hi Paul. Check what your flattener requires, mine is 55mm to camera sensor. 


On 7 Nov 2020, at 13:20, Paul Meesters <p.h.meesters@...> wrote:

Hi,
last night I finally got round to using my Explore Scientific refractor (FCD100 - 10207 - CF) for the first time, mounted on the Exos2.

I have a field-flattener attached, and a T2 adaptor for my Sony A7iii. Whatever I do with the focusing in-or-out, I never get any stars in the display of my camera. 
It's not for using wrong camerasettings. I used a 15 seconds shuttertime at 32000  ISO.. no stars at all (and no, I did not forget the lens cap)

I'm not sure what I need to do to get a picture.. Do I need more extender tubes ? It's already sticking out more then I like, since the T2 adapter and the field flattener are very big...

<Camera_Connection.jpg>


Any advise is appreciated :)

Greetz
Paul

--
Michael Whitaker
Wakefield, UK. 
MOUNTS. Exos-2 PMC Eight..
SCOPE: RVO Horizon 72ed. 
CAMERA: Not Applicable. 
SOFTWARE: Just iPad at moment. 


Harry
 

Hello,
Have you used your set up during the day, focused on a distant object with a prominent point ( top of flagpole), and ensured you are in focus?
--
Harry
Vero Beach, FL

Mounts: ES iExos 100-PMC Eight
Scopes: ES  ED80CF, ES AR102,  Meade ETX 90 EC (Deforked)
Guide: ZWO 30mm Mini, ZWO ASI120MM-Mini
Software: ASIair Pro, iPad Pro, MacOS, Starry Sky Stacker, Affinity Photo, Lightroom,  SkySafari Plus
Cameras: Nikon D600, D5500
Misc: ES USB Power Bank, Rigel QuikFinder, 0.8x Focal Reducer
Filters:  Optolong L-Pro, L-eNhance






Harry
 

Paul, I forgot to mention on my ES 80, I have to use an additional 2 inch extension tube plus the .8x focal reducer (looks similar to your field flattener), with my crop sensor DX5300, and focus no problem. I see on the ES website your scope comes with 2 extension tubes. Mine did also. I believe that is your issue.
--
Harry
Vero Beach, FL

Mounts: ES iExos 100-PMC Eight
Scopes: ES  ED80CF, ES AR102,  Meade ETX 90 EC (Deforked)
Guide: ZWO 30mm Mini, ZWO ASI120MM-Mini
Software: ASIair Pro, iPad Pro, MacOS, Starry Sky Stacker, Affinity Photo, Lightroom,  SkySafari Plus
Cameras: Nikon D600, D5500
Misc: ES USB Power Bank, Rigel QuikFinder, 0.8x Focal Reducer
Filters:  Optolong L-Pro, L-eNhance






James
 

Based on the picture, I would say that you probably do need more extension tubes and you may also want to check the back focus requirement like Mick mentioned. I have a MC that I have to use an 8cm extension along with my other adapters. One other thing to check is what focal lengths your flattener works with. For example, my flattener will only work with scopes with a focal length of 500mm to 1000mm, so I can't use it with my MC as it's focal length is 1900mm. Lastly, just for focusing, set your camera to it's max shutter time (mine is 30 sec) and ISO to 400-1600.

Good luck and clear skies.


--
Mounts: Explore Scientific EXOS II GT, iEXOS-100, Celestron AVX
Scope: Explore Scientific AR102, AR152, FirstLight 152mm Mak-Cassegrain, SpaceCat 51
Guide Scope: Astromania 50mm Guidescope (190mm focal length)
Guide Camera: ZWO ASI120MM Mini Monochrome
Camera: Canon RP (IR modification)
Software: PHD2, ASCOM, and APT


Paul Meesters
 

On Sat, Nov 7, 2020 at 02:32 PM, Mick Whitaker wrote:
Hi Paul. Check what your flattener requires, mine is 55mm to camera sensor. 
I have no clue. The flattener came without any documentation, and there are no markings on the flattener anywhere. :(


Wes Mcdonald
 

Paul if the focus is way off you won’t see a star in live view, maybe not with time exposure.  Do as suggested:  take your scope outside in daylight and get it focused using live view on a far away tree top or some such.   Mark your focus position.   Then you will be close at night.

Wes

--
Wes, Southport NC
EXos2-GT PMC-8, iExos 100
ES ED 127, 10" LX200GPS+wedge, Astro-Tech 8" Newt, ETX-90, 60mm no-name guide scope ~ 260mm FL
Polemaster, Orion ST-80 and SAG, ZWO 290MM, D5300 astro modified
Nina, Bootcamped Mac Mini control computer, RDP to iMAC
110 amp hour lead acid deep discharge battery for field power
Electrical Engineer, Retired


Ian Morison
 

Hi Paul,
   I have a very similar setup with Sony a7 ii.   When in focus you should see stars in the live view at 2000 ISO so making it easy to align.  First having tested in the day as suggested go to something bright - I used Mars last night  - and used focus peaking.
All the best.

Cheers,

Ian

On Saturday, November 7, 2020, Paul Meesters <p.h.meesters@...> wrote:
Hi,
last night I finally got round to using my Explore Scientific refractor (FCD100 - 10207 - CF) for the first time, mounted on the Exos2.

I have a field-flattener attached, and a T2 adaptor for my Sony A7iii. Whatever I do with the focusing in-or-out, I never get any stars in the display of my camera. 
It's not for using wrong camerasettings. I used a 15 seconds shuttertime at 32000  ISO.. no stars at all (and no, I did not forget the lens cap)

I'm not sure what I need to do to get a picture.. Do I need more extender tubes ? It's already sticking out more then I like, since the T2 adapter and the field flattener are very big...



Any advise is appreciated :)

Greetz
Paul


Paul Meesters
 

On Sat, Nov 7, 2020 at 02:44 PM, Harry wrote:
I have to use an additional 2 inch extension tube plus the .8x focal reducer (looks similar to your field flattener), with my crop sensor DX5300, and focus no problem. I see on the ES website your scope comes with 2 extension tubes. Mine did also. I believe that is your issue.
I have 3 extender rings, but they don't fit anywhere in the setup.. they're too large in diameter :(


Patrick Maher
 

You need to check the website where you purchased the field flattener.  That is usually where you will find the specs for required backfocus.  Typically, however, this is 55mm give or take a little bit (it may require some adjustment to get the corners just right).  I don't think any field flattener comes with instructions today.  All info is online.  

As others have mentioned, you will probably also require another extension tube...   probably a 2" tube would do it...  in order to get focus.  

Have you tried to get focus without the flattener so you have a starting point?  That would be the easiest and most logical.  

Patrick
--
Explore Scientific iEXOS-100 and EXOS-2GT (non-PMC)
Explore Scientific ED 102mm Refractor


Patrick Maher
 

I should also add that with your type of T2 adapter, you should be at 55mm now.  It appears as though your T2 adapter already has the correct length of backfocus length to go with your camera's lens flange distance.  These types of T2 adapters put you at 55mm, usually.  

Patrick
--
Explore Scientific iEXOS-100 and EXOS-2GT (non-PMC)
Explore Scientific ED 102mm Refractor


Patrick Maher
 

If those extension tubes came with the telescope (they appear to be ES extension tubes), then they fit on your scope.  You need to unscrew the collar from the back end of the focuser tube and then screw on one or two of these extensions.  Then screw that collar back onto the end of the extension tube.  Those are probably focuser extension tubes specifically for your focuser.

Patrick
--
Explore Scientific iEXOS-100 and EXOS-2GT (non-PMC)
Explore Scientific ED 102mm Refractor


Paul Meesters
 

On Sat, Nov 7, 2020 at 02:59 PM, Patrick Maher wrote:
Have you tried to get focus without the flattener so you have a starting point?
eehmm, I can't do that. I have no other means to attach the T2 adapter to the telescope .. nothing fits..


Paul Meesters
 

On Sat, Nov 7, 2020 at 03:05 PM, Patrick Maher wrote:
You need to unscrew the collar from the back end of the focuser tube and then screw on one or two of these extensions
Djeez, I have no idea how to do that, which screws do I need to use for that ? I'm afraid I will do the wrong ones and destroy the telescope..


 

I had to get a different camera as my Canon M50 was impossible to get focus with the flattener. I bought a second hand Canon 650d and had no problem. 


On 7 Nov 2020, at 14:16, Paul Meesters <p.h.meesters@...> wrote:

On Sat, Nov 7, 2020 at 03:05 PM, Patrick Maher wrote:
You need to unscrew the collar from the back end of the focuser tube and then screw on one or two of these extensions
Djeez, I have no idea how to do that, which screws do I need to use for that ? I'm afraid I will do the wrong ones and destroy the telescope..

--
Michael Whitaker
Wakefield, UK. 
MOUNTS. Exos-2 PMC Eight..
SCOPE: RVO Horizon 72ed. 
CAMERA: Not Applicable. 
SOFTWARE: Just iPad at moment. 


Paul Meesters
 


Managed to it by unscrewing one screw with the small allan (hex) key. Fitted one 2" extender, and am able to focus now :)

The houses opposite my house, distance approximately 100 meters according to Google Maps, are in focus


Harry
 

Paul, As I mentioned, my Orion .8x FR looks identical to your FF. On my Nikon, I use 2 different T adapters, see attached pics. Both are just attachment adapters. No additional spacing. On the left threads are 42mm (std),,on the right is a “wide” thread 48mm. I use the wide one with the FR. The wider thread helps prevent vignetting. With the wide one I also need one 2 inch extension tube. The 42mm is used with no FR.

Since your T2 adapter has some extension  built in, perhaps a smaller additional extension is required, or a T ring (probably like my wide), with no extension, plus one 2 inch extension. Extension tube kits are available with multiple lengths,  The pic with the camera shows my setup. I would just screw the ext tube on to the telescope.

Hope this helps.  Harry

--
Harry
Vero Beach, FL

Mounts: ES iExos 100-PMC Eight
Scopes: ES  ED80CF, ES AR102,  Meade ETX 90 EC (Deforked)
Guide: ZWO 30mm Mini, ZWO ASI120MM-Mini
Software: ASIair Pro, iPad Pro, MacOS, Starry Sky Stacker, Affinity Photo, Lightroom,  SkySafari Plus
Cameras: Nikon D600, D5500
Misc: ES USB Power Bank, Rigel QuikFinder, 0.8x Focal Reducer
Filters:  Optolong L-Pro, L-eNhance






Harry
 

On Nov 7, 2020, at 10:06 AM, Harry via groups.io <flykai1@...> wrote:

Paul, As I mentioned, my Orion .8x FR looks identical to your FF. On my Nikon, I use 2 different T adapters, see attached pics. Both are just attachment adapters. No additional spacing. On the left threads are 42mm (std),,on the right is a “wide” thread 48mm. I use the wide one with the FR. The wider thread helps prevent vignetting. With the wide one I also need one 2 inch extension tube. The 42mm is used with no FR.

Since your T2 adapter has some extension  built in, perhaps a smaller additional extension is required, or a T ring (probably like my wide), with no extension, plus one 2 inch extension. Extension tube kits are available with multiple lengths,  The pic with the camera shows my setup. I would just screw the ext tube on to the telescope.

Hope this helps.  Harry

--
Harry
Vero Beach, FL

Mounts: ES iExos 100-PMC Eight
Scopes: ES  ED80CF, ES AR102,  Meade ETX 90 EC (Deforked)
Guide: ZWO 30mm Mini, ZWO ASI120MM-Mini
Software: ASIair Pro, iPad Pro, MacOS, Starry Sky Stacker, Affinity Photo, Lightroom,  SkySafari Plus
Cameras: Nikon D600, D5500
Misc: ES USB Power Bank, Rigel QuikFinder, 0.8x Focal Reducer
Filters:  Optolong L-Pro, L-eNhance





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--
Harry
Vero Beach, FL

Mounts: ES iExos 100-PMC Eight
Scopes: ES  ED80CF, ES AR102,  Meade ETX 90 EC (Deforked)
Guide: ZWO 30mm Mini, ZWO ASI120MM-Mini
Software: ASIair Pro, iPad Pro, MacOS, Starry Sky Stacker, Affinity Photo, Lightroom,  SkySafari Plus
Cameras: Nikon D600, D5500
Misc: ES USB Power Bank, Rigel QuikFinder, 0.8x Focal Reducer
Filters:  Optolong L-Pro, L-eNhance






Jerry Hubbell - Explore Scientific VP Engineering
 

This topic belongs in the PMC-Eight Applications subgroup not in the Main forum.  Please continue your conversation there.

Thank you.
--
Jerry Hubbell
Vice President of Engineering

Explore Scientific, LLC.
jrh at explorescientific.com

www.explorescientificusa.com
1010 S. 48th Street
Springdale, AR 72762
1-866-252-3811

Author: Scientific Astrophotography: How Amateurs Can Generate and Use Professional Imaging Data
             Remote Observatories for Amateur Astronomers: Using High-Powered Telescopes From Home


Mark Slade Remote Observatory (MSRO) IAU MPC W54 Equipment
Wilderness, VA
Mounts
: ES PMC-Eight G11 + Telescope Drive Master (TDM)
Scopes: ES 165 FPL-53 ED APO CF, ES 102 FCD100 ED APO CF
Cameras:  QHY174M-GPS + FW, QHY163C
Misc: 3-inch 0.7x Focal Reducer Field Flattener, Filters: Luminance,
Red, V-band Photometric, Diffuser, 200 lpmm Spectral Grating

Software: MaxIm DL 6, Cartes du Ciel, Astrometrica, AstroImageJ, AutoStakkert!