When you mix and match brands it might not always work, ie Takahashi, Baader and Televue.
The easiest and approximate way to work out is to use your focal length of your telescope.
Approximately measure where your front element meets the tube down to the back of your visual back (imaginary centre line). Now add on the diagonal which has a 112 mm light path. (I have the same one). Insert the eyepiece, measure to the front element and add the eye relief of the eyepiece.
If this is longer than your focal length of the telescope, you need to reduce it by at least that much with a shorter extension. Make sure your focuser is racked in all the way!
Do this with your longest and shortest eyepieces to make sure they will all come to focus and add a bit of leeway.
You can always rack your focuser outward from here, but not in!
Steve, the FC100DC has an extension tube between the OTA and the focuser.
If you unscrew the focuser and then remove the green extension tube from the OTA and then screw the focuser directly to the silver OTA ring, you will be able to gain enough backfocus to use your Baader BBHS 2" mirror
No joy.... not enough travel the other way now. If I pull the diagonal out I get perfect focus.
An extension tube half the size would do it. It's a shame the Tak dealer won't tell me what one I need or even if there is one so I can buy it off him as I'm not an established customer.
Have I done something to offend this guy or is he always like this???
My initial email....
Hi C,
hoping you can help me. I have an FC100DC with a 2 inch back and use a Baader 2 inch diagonal.
I have a set of Televue Plossls and there is not enough in travel to bring them into focus.
I am a visual observer only.
Do you sell an adapter or do you have any suggestions to help solve this?
Many thanks,
Steve
his reply....
Hello,
The Cat. Number for the Tube Holder is
TKA36420.
C
My response...
Hi C,
I am not after a tube holder. I can't get my televue possls to come to focus using a 2 inch Baader diagonal.
Do you sell an adapter to rectify this?
Steve
Response from 2nd gentleman...
Hello,
Sorry, we give technical information only
to established customers.
L (AEC)
I replied back...
L,
I am after an adaptor or something to rectify my problem. I will never be an established customer if you wont sell one to me
Steve
I didn't hear back until 10 minutes ago when this arrived....
Hello again,
I don’t think C is going to worry whether you become an AEC customer or not.
In any case, we don’t know of any Adapter that can fix your problem.
Unless you got this telescope second hand, you should have got it from us.
Also, you should have got a Takahashi Star Diagonal, as well as Takahashi High power Eyepieces,
not Teleview or any other brand, which are not dedicated to specific Takahashi telescopes.
Hi Steve,
Claude is just a Takahashi outlet so I wouldn’t blame them too much. Just after sales I guess but could have a better response
Wait for the other Tak enthusiasts to chime in, they’ll probably tell you need an extension from another scope or there abouts.
Cheers
I have a takfs102 and I am pretty sure it comes to focus with the Baader diagonal I have with the right number of odd little Tak extenders or 17mm m72 extenders . Check the system chart .
No joy.... not enough travel the other way now. If I pull the diagonal out I get perfect focus.
An extension tube half the size would do it. It's a shame the Tak dealer won't tell me what one I need or even if there is one so I can buy it off him as I'm not an established customer.
Buy one of these from Andrews Communications and will fix your out focus problem they are well made
35mm extension, has brass compression ring - FF113 $39
You don't have to go crazy Tak prices for extension tubes and at that price you could probably go the 50mm as well and then you're well covered the FC100DF was made for visual out of the pair
Maybe their point is that with the standard Tak back for visual you need to stick with all of the Tak extenders , in my case 2x 43mm thread 34 mm long plus the eyepiece coupler and 21 mm f72 Up front. Take away enough to make the diagonal work depending on other reducers etc. as pictured.
However you could use all cheaper T2 extenders as I use for imaging, second image, in any size available but then you need an after market Borg or similar visual back to screw in to the focus tube instead of the Tak one plus some quality t2 fittings. Which the Tak dealer will not want to talk about. I use them but the cheaper ones can be pretty ordinary.
Many thanks folks, gives me a few options to look at.
Ray his point was "you didn't buy it off us so we are not going to help you"
I must say that was Leon. Claudes reply wasn't dismissive he just pointed me to a clam shell OTA holder which was not what I asked for.
People use Taks every day with every brand of EP's using various adapters. not just limited to Tak EP's. I just wanted to buy an adapter.
I'm also after a Mewlon. I wont be buying from them.
Very weird (and IMO unprofessional) way to deal with a prospective customer. The first reply maybe I can understand, easy to make a mistake and not answer the email you think you are. The rest are just silly for any customer service organisation. "Sorry, we give technical information only to established customers." rates in my book as the height of idiocy in any sort of retailer, the last mob who treated me to that response did themselves out of a couple of grand in sales on the spot (Stuff for my race car) I turned around and went to a competitor the same day.
After all that, glad you managed to cobble together a combination that works.
Very weird (and IMO unprofessional) way to deal with a prospective customer. The first reply maybe I can understand, easy to make a mistake and not answer the email you think you are. The rest are just silly for any customer service organisation. "Sorry, we give technical information only to established customers." rates in my book as the height of idiocy in any sort of retailer, the last mob who treated me to that response did themselves out of a couple of grand in sales on the spot (Stuff for my race car) I turned around and went to a competitor the same day.
After all that, glad you managed to cobble together a combination that works.
Bit of a funny story on this one.......my brother in law who had just retired after a long stint in the navy returned to Melbourne with quite a large ‘package’ in hand. Whilst renovating his newly purchased house he heard an advertisement on the radio stating there was a one day only sale on the newly released Monaro Coupe (the latest release, not the 70’s). Needing a car he shot down to the dealership covered in paint, sawdust and ripped old crappy overalls. After walking around a shiny new Monaro for 30 minutes with no salesman in sight he asked for some help to be dismissed and told ‘they are very expensive you know’. He questioned the salesman on the comment and it was clearly communicated that the salesman wasn’t willing to waste his time on who he thought was a tyre-kicker wanting to go for a joy ride. Bro in law walked out in disgust.
To cut a long story short a week and a half later we went and picked up a brand new fully optioned Monaro from another dealer.....on the way home my bro in law pulled into the service driveway of the first dealer, asked for the sales manager and then explained what had happened with the first salesman and how in disgust he went straight to another dealer and bought the car with cash.
..........we then left the dealers driveway in a cloud of smoke laying down two rubber tracks for them to remember us by.
Great. Always a good thing to get sorted without having to order something..
I do not mean to excuse the TAK dealer, they are clearly in trouble in many ways and there should not be a monopoly.
I am not wedded to the whole Tak thing at any cost.
But having owned a second hand Tak and used in different ways, I understand now why they call it a system chart and Tak deliberately separates their System from all the others. Not neccessarily about the higher prices but keeping in business with a reliable system,.
Quote:
Originally Posted by madtuna
Sorted!!
Went through a box of bits and pieces and found an extension that fitted.
Got my latest Tak part from AEC this morning, after it had somehow made an unexpected stop with Peter Ward (thankfully!) before Peter sent to the correct address. That was a very lucky twist of good fate that Peter received it and not a random recipient expecting a bottle of Claude’s herbal COVID-19 cure
Claude had picked up on this human error, so at least it all turned out well.
TAK adapters and accessories are pretty expensive. First thing I did when I got my FSQ was get an adapter made from the TAK thread at the back of the scope to a standard thread I could use with all the existing tube extensions, focusers, filters, AO, etc... that I already had. I did the same for the CN-212.
I think I'll go down that route also Marc...thanks.
I have a range of EP's and would like to use what ever I want with the scopes I have and generally don't have a problem.
I just bought this set of TV plossls off a member here and couldn't get focus so I fired off what I thought was a polite and courteous email to the Tak dealer asking if they had an adaptor I could buy to solve the problem or if they had any suggestions.
"Hi Claudio,
hoping you can help me. I have an FC100DC with a 2 inch back and use a Baader 2 inch diagonal.
I have a set of Televue Plossls and there is not enough in travel to bring them into focus.
I am a visual observer only.
Do you sell an adapter or do you have any suggestions to help solve this?
Many thanks,
Steve"
Got this this morning...twice (edit: now 3 times)
"Thank you for letting various Astronomy Forums to know that A.E.C. wants nothing to do with people
who buy new Takahashi telescopes and Mounts from non-authorized overseas Dealers, and then expect us to sell them some cheap adapters, as well as supplying them with technical information.
Make sure you also put that in the Forums.
Claude (AEC)"
Not sure where they got the idea I bought it new from a non-authorized OS dealer, or was after technical information. I bought it second hand off a member here.
All I wanted was a damn adapter or suggestions to solve the problem!
If I have good experiences with dealers like I've always had with Andrews, Bintel and Astro Anarchy I have no problems letting people know. And if I have a shocker like I just had with AEC I have no problems letting people know also.
Cheers!
P.S. Ray...I agree it is a system.
But just as I can put after market rims on my Landcruiser I should be able to use after market EP's and diagonals just like most members here do every day.
Also I shouldn't fear being treated like a dick from my local Toyota dealer when after a part because I didn't buy it off him.