Explore Scientific 80mm ED APO

[Dinoboy]

I recently received the above scope and have not had the chance to use it at night. I got this scope in order to do some Astrophotography. So the best thing, I thought, would be to use it during daylight hours, to get familiar with it. Hum, no matter what I do I cannot get anything like focus, I can see the Moon but only as a blob (this gives a new meaning to the word blob) I have tried different ep's, 18 and 32mm both Celestron, without an extension tube and with one. The star diagonal is an Altair Astro dielectric. I cannot find a way of fitting onto the scope the extension tubes that came with it so I purchased a Revelation one, not cheap, and it fits OK and allows me to fit the diagonal also, I thought that as the focuser travel is about 45-50mm fitting the extension tube may be the answer. It is no use trying to do AP unless I can get focus, any ideas !!M

[rwilkey]

Hi Dinoboy, you should not need extension tubes when using the telescope ordinarily, make sure you just use the basic diagonal to insert your eyepieces, also make sure the tension screw is not too tight.  Is it the 2" diagonal that you are using, ensure the 2" to 1.25" adaptor is fitted when using 1.25" eyepieces. Use the 32mm ep to start with.  Focus should be somewhere about half way out and keep turning while the object appears to get smaller, turn slowly when the object gets small and if it's a star you should reach a pinpoint of light.  Any chance of posting a picture of the focuser end set up ready to go, that might help us?

[Dinoboy]

Hi and thanks for replying. I do not know how to load pics onto this site from my iPad. I have tried both with and without the extension tube but as I said there is just a white blob of the moon but no detail of any sort. I have gone from one end of the focuser to the other using both my Celestron ep's (18 and 32). I have emailed Explore Scientific and await their answer. The owners manual is mainly about the finder scope other than that it is useless. I cannot see where the extension tube/s that came with the scope fit so unless I can find out it seems to be a waste of manufacture. I really want to sort this out so that Ican start doing some AP which is another learning curve.

[nicks90]

have you tried pointing the scope at a far away church spire / power pylon and manually holding an EP up to the back of the focuser with no extension or diagonal attached?

Might sound daft, but remove everything from of the focus tube (even the 2" ep adaptor so its just the bare tube!) and rack the focuser all the way in. Then hold the ep up the back of the open focuser and just move the ep backwards in your hand until things are sort of in focus. You can then physically see how far the EP is away from the back of the focus tube. With that rough measurement (you can even hold a ruler next to it and assist in holding the ep in line with the ota) you can gauge what overall focus distance is required. its then a simple exercise of measuring the length of the diagonal and tubes to get the right length.

I had a simillar problem with a cheapo 70mm frac i had given to me. It came with a x1.5 correct image diagonal, but it didnt say it was x1.5 anywhere! So when I upgraded to a 90 deg decent diagonal, it wouldnt achieve focus! using this method helped me work out I need to chop 10mm off the back of the tube and remount the focuser. Not saying you need to do something so drastic, but manually holding the ep up at the back end does work!

[ronin]

I have a feeling that ES supply the extension for a reason, but what that is I have no specific recollection. They cover both visual and AP so you do not have to buy an extention tube.

You will have to look around for the order the bits should go in for visual.

Usually it is Scope-Focuser-Diagonal-Eyepiece for visual.

Then it would be Scope-Focuser-Extn-DSLR for AP.

That assumes that the "standard" set up is for visual, and it may not be. ES may have made the "standard" as AP.

Do ES not give a diagram in the manual - assumng there is a set up manual.

You may be better asking the order of things on the CN forum as that will have been where I read about it all. I think it caused problems over there about which bit went where if it went anywhere. Although it should be reasonable to work out what is required where. However I doubt that at any stage will you need all the bits on.

[Geordie mc]

I have the Explore Scientific 102ED APO. It came with just the diagonal and an EP. Focus for visual use is fine with just these items. When I remove the diagonal I add an extension tube for imaging with a ccd. Do some day tests on a far off object using just the scope and an ep as suggested above. If all seems well then maybe the diagonal is at fault?

[Dinoboy]

Hello mainsequance thanks for your reply but what is the cn forum and where can I find it?

Regards

[NGC 1502]

Hello mainsequance thanks for your reply but what is the cn forum and where can I find it?

Regards

Link here to CN (Cloudy Nights)   http://www.cloudynights.com/page/index.html

Regards, Ed. 

[Stridor]

I have the Explore Scientific 102ed also; I had to fit one of the two supplied extesion tubes to attain a good focusing.

[Ahab]

I have the Explore Scientific 102ed also; I had to fit one of the two supplied extesion tubes to attain a good focusing.

Yes, me too! They do have a manual but it's on there website. They are very good at answering e-mails.

[glowjet]

Just in case you were still in limbo, I came across this in their public informaton on the ED 80m APO, which might be of interest...

Collimatable optics: One of the bonuses of owning a refractor is that, compared to standard reflector telescopes, they almost never require realigning of the optics (collimation). However, any air-spaced refractor telescope may require optical recentering if the lens elements are knocked out of alignment by a heavy blow during shipping or use. Removing the dew shield will give you access to the lens centering screws in the sides of the lens cell, which you can then adjust yourself by referring to the supplied instructions. You can also send your scope to Explore Scientific’s Service Center for precision alignment. A standard service charge applies for factory realignment.

And a picture of the ED 80mm APO set up, shows the diagonal direct into the end of the focuser.