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The Focusing Problem


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The 150PDS & 200PDS have a slightly shortened tube optimised for prime-focus photography.

You can easily add spacers when you need more outward focus, but (if the camera won't focus when the focuser is fully in) you normally have no method to shorten the focus. There may be 'accessories' provided with the scope which can be swapped out to allow cameras but are often left in the box unused. People rarely read the manuals 🙂 to see what they are for.

HTH Steve

Welcome to SGL

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Posted (edited)
39 minutes ago, StevieDvd said:

The 150PDS & 200PDS have a slightly shortened tube optimised for prime-focus photography.

You can easily add spacers when you need more outward focus, but (if the camera won't focus when the focuser is fully in) you normally have no method to shorten the focus. There may be 'accessories' provided with the scope which can be swapped out to allow cameras but are often left in the box unused. People rarely read the manuals 🙂 to see what they are for.

HTH Steve

Welcome to SGL

Could this be a problem with this telescopes? Need accessories?

sorry for my teribble english...

Edited by sadikberkevren
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1 hour ago, sadikberkevren said:
Could this be a problem with this telescopes? Need accessories?

sorry for my teribble english...

No problem with the English.

The 150PDS & 200PDS are good with Canon DSLR they are designed for photographic. The 150P/200P are aimed at visual and may need a barlow or special 'T' adapter.

Is this a scope you have already or one you intend to buy?

 

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2 hours ago, sadikberkevren said:

Why?

Because with a DSLR, the light from the mirrors is not projected far enough out from the tube.

2 hours ago, sadikberkevren said:

Skywatcher 150 or 200P-DS and CANON EOS 550D works together

Yes. Both of those telescopes will reach focus with a 550d.

 

2 hours ago, sadikberkevren said:

Need accessories?

Yes. To fit the camera you need this and this.

HTH

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56 minutes ago, StevieDvd said:

No problem with the English.

The 150PDS & 200PDS are good with Canon DSLR they are designed for photographic. The 150P/200P are aimed at visual and may need a barlow or special 'T' adapter.

Is this a scope you have already or one you intend to buy?

 

Yes, I will buy the 150PDS or 200PDS with HEQ5. I have new questions: Is EQ5, good for tracking? HEQ5 is too expensive... And, what is the ideal exposure time for astrophotography? For example, is 1 hour exposure for Andromeda Galaxy good? Or, is it unnecessary?

 
 

image.png

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It's a tricky question to answer without knowing how and where you intend to use them the most, or if it's only going to be used infrequently.

For a 200PDS the HEQ5 would be my starter, perhaps EQ5 for the 150PDS.   I'd also recommend the belt driven model which is much quieter and a worthwhile option.

For imaging times it depends on how your tracking is and whether you use a guidescope but a starting point would be 30 to 60 second exposures repeated, and see your results after say 30mins worth and then an hours worth. If your mount is tracking well enough you can add extra exposures over several sessions.  It's always nice to have a look at short session results to get some feedback from your equipment and some images to get to know the software to align & improve the end result.

There are dedicated sections for all of the above, and better heads than mine to help.

BTW Please feel to show your location as you may meet some native speakers from your home as well on here, we have a nice international following too.

Regards

Steve

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You can start with short duration captures of 30secs and see if you get stars as nice pinpoints or as small lines. If okay try 60secs, but longer than that you'll likely need a guide scope.  With a big scope like a 200PDS on the HEQ5 you are pushing the limits without a guide scope.

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