150p DS focus

[nightfisher]

tried my 150p ds and micro four thirds dslr at prime focus, no where near enough in focus, changed the 2" to 1.25 adaptor to a low profile one, still same problem.....any ideas chaps

[Chris]

hmmm thats strange, what camera is this exactly and what is the rough distance from the front of the camera to the chip? I've used a CCD plus filter wheel on this scope so it does surprise me to hear this.

[Chris]

I've also used a DSLR with T-ring and coma corrector with no probs. What adaptor thickness are you using. Also if you are close to focus you can use the primary collimation screws to push the primary mirror slightly further up the tube although really you shouldn't have to resort to this??

[nightfisher]

Its the olympus pen EPL-1 camera and chip is aprox 12mm from front of camera, not best pleased

[Chris]

Well the cameras not the problem then with such a short chip distance. Do you have a T-ring on the camera which may screw directly onto the draw tube?

[Chris]

If you can take a pic of how you have the camera attached it might help. I for one would be interested to see, it might be something obvious thats not come across in words?

[nightfisher]

here are some pics

[tbird]

Hi Jules, the 1 1/4 EP adapter should separate and just the ring attaches to the T ring.

[Lonestar70]

Hi Jules,

It is not clear from your photos, but I suspect that your camera adaptor is the one designed to allow connection of T2 threaded lenses to your camera... hence it's long length... this is to allow such lenses to reach focus with a 55mm backfocus.

your camera has a back focus of 20mm so for astro work you need a shorter adaptor such as this one: -

http://www.teleskop-express.de/shop/product_info.php/info/p3676_T2-ring-for-Micro-Four-Thirds--Panasonic--Olympus-.html

This is designed to perform both functions and you would need to use it without the extension.

Instead you would use either the 11/14" -T adaptor: -

http://www.teleskop-express.de/shop/product_info.php/info/p201_TS-Adaptor-1-25--to-T2---Focal-Adaptor-for-1-25--Focuser.html

Which I think you already have, or the 2" -T adaptor: -

http://www.teleskop-express.de/shop/product_info.php/info/p200_Adaptor-2--to-T2---low-profile.html

either would fit straight into your focuser.

I would suggest the 2" version since this will reduce/eliminate any Vignetting.

both are threaded for filters.

The one you have at the moment would probably work Ok with the SW Coma corrector, since this needs the 55mm back focus distance.

Hope this helps.

Best regards.

[Uranium235]

If the camera chip is only 12mm into the body of the camera, then you should have loads of room to play with. If anything, when mounted with a short adapter you should be winding the focus out, not it. If used with a CC, then you will need to buy some extension tubes to make up the correct CC > Chip distance.

Try to avoid using 1.25" adapters, as they wont do your images any favours (severe vignetting).

Hope that helps!

[Chris]

ah yes I'm glad I asked for pics You have quite a large distance between the focuser and the camera with that 1.25" adaptor in the way, as tbird says unscrew it and your T-ring shouls screw onto the 2" bit.

I think you'll have much more luck after that but if not let us know;)

Chris

[nightfisher]

Im stuck on this one, the T thread for the camera has the long body, not the 1.25 nose piece, i bought the 150p ds for visual grab an go, plus basic imaging on the main mount, i know this sounds a little negative but my interest in deep sky imaging has just done like the moon, and waned, every time i try this imaging i run into stupid problems, that never seem to go away, if im to do deep sky i need a bahtinov, now i need a new T ring, if i can get one short enough for my silly camera, thats another £50 into a pot of uncertainty! so i now have a 150 for grab an go only. many thanks for the help

[Dodge]

The camera adapter looks like a 2" adapter, so if you lose all the 1.25" stuff in between (it looks like it unscrews from your camera adapter) and remove the 2"-1.25" EP adapter, it should just plug directly into the focuser.

[RikM]

The camera adapter looks like a 2" adapter, so if you lose all the 1.25" stuff in between (it looks like it unscrews from your camera adapter) and remove the 2"-1.25" EP adapter, it should just plug directly into the focuser.

I agree.

Does A unscrew from B? Does B fit into your focuser without the 1.25" in place?

[nightfisher]

I agree.

Does A unscrew from B? Does B fit into your focuser without the 1.25" in place?

Yes they do unscrew (A + B ) but you guessed, its still to large to fit into the 2" section by about 3mm, but good try, would have been nice. Have to say i feel i dont really want the 150 now, seeing it only serves half the purpose i bought it for, this is all down to the silly camera

[Chris]

Would you like my Canon 350D and T-ring, I was thinking of going pure mono CCD anyway? I know you not suppose to offer on threads but as it might help you I'll risk it

[nightfisher]

No thanks, im not buying any more camera`s or bits to hold them, might try my DMK mono in the 150, good for the moon if nothing else, but then i have a 180 mak for high res luna

[Chris]

Thinking caps still on.

[RikM]

Honestly Jules the 4/3rds adaptor Lonestar70 linked to http://www.teleskop-express.de/shop/product_info.php/language/en/info/p3676_T2-ring-for-Micro-Four-Thirds--Panasonic--Olympus-.html would do the trick. The bayonet adaptor would fit to your camera, then you unscrew the two parts of the Skywatcher 1.25" adaptor to reveal the T-thread and either the bayonet adptor would screw straight on or if not enough out focus on the low profile focuser, then use the T2 extension included with the 4/3rds adaptor in between.

[nightfisher]

Honestly Jules the 4/3rds adaptor Lonestar70 linked to http://www.teleskop-...--Olympus-.html would do the trick. The bayonet adaptor would fit to your camera, then you unscrew the two parts of the Skywatcher 1.25" adaptor to reveal the T-thread and either the bayonet adptor would screw straight on or if not enough out focus on the low profile focuser, then use the T2 extension included with the 4/3rds adaptor in between.

will keep it in mind, i fully understand how it would work, but i feel really down hearted about this, its the second time i have bought a scope to play with imaging only to be scuppered from word go! i could buy the low profile T ring from TS and it still might not come to focus, then i have chucked another 41 euro into a failed project as the TS ring will only give me another 15mm in travel compared with the adaptor i already have

[Moonshane]

could the end (not the camera end of course) of B be cut off as there appears to be a lip which if removed might allow it to slide into the focuser?

[RikM]

will keep it in mind, i fully understand how it would work, but i feel really down hearted about this, its the second time i have bought a scope to play with imaging only to be scuppered from word go! i could buy the low profile T ring from TS and it still might not come to focus, then i have chucked another 41 euro into a failed project as the TS ring will only give me another 15mm in travel compared with the adaptor i already have

No, it will reduce the length enormously. The only bit that will sit between you camera body and the top of the focusser draw tube will be the bit labelled Part A: T2 bajonet adapter in the TS add. Take a look at your Skywatcher 1.25" EP holder and unscrew it in half. The long 1.25" bit won't be used, only the flat 2" bit that fits into the focuser and the new TS Part A (maybe 20mm then your camera body. You don't need your current 4/3 adaptor and probably not the 55mm Part B T extension from TS unless you get a coma corrector later.

[nightfisher]

could the end (not the camera end of course) of B be cut off as there appears to be a lip which if removed might allow it to slide into the focuser?

looking at it, it would be possible, but it would need machining of, and this would remove the thread that the 1.25 nose piece screws into, if i still worked in engineering i would take a gamble on it and lathe it to size, but no access to facility's these days, good thinking shane

[Moonshane]

given that it will end up in the focuser, I'd not worry too much if it will definitely fit. if it does and it were me then I'd use a careful/slow hacksaw and touch in with a bit of matt black spray. do you have a mitre saw for cutting skirtings etc? that might work even. I have a dovetail version of the 1.25" bit you can have when you come over. this might help you too. you/I could always drill and tap the remainder of B to allow this to be fitted.

[nightfisher]

Just measured up with digital vernier, the original T ring would still need machining to fit into the 2" focus tube, it would need .05 mm turning of the diameter, as its 51.14 OD above the step that could be cut of