Baader / Solar Spectrum Telecompressor 0.7x

[swisswalter]

Hi Mark

great you ordered the new toy. We should find out also if we need a special TZ for CaK or so . I did my last shots with a TZ4 (Ha optimised ) in CaK

[marktownley]

It was just a matter of time..................

ha ha ! You're right there Mike

[marktownley]

Ok, so said Baader Telecompressor arrived today...

First point to note, as said in the advertisment it has a male 2" fitting at either end. This is NOT m48, i'm guessing it's an m50.8(?) - so not a straightforward as screwing it on the bottom of a 2" eyepiece fitting...

It's also really heavy, you know when you pick something up and it's just loads heavier than it looks, well this is one of those. So, as you would expect nothing less from me the next thing I did was take it apart... It is a 4 element lens; 2 cemented pairs separated with a spacer, total thickness 16mm from front to back glass face. Rather different than my 2" antares 0.5x reducer I found that I planned to put the glassware from the Baader into (doesn't fit!)

So tonight is mod night, a rummage through the boxes of many bits with a view to putting baader glassware in a more conventional housing...

[grimble_cornet]

That's very prompt service Mark - my focuser has been in customs for almost a week!
The double-ended 2" male fitting seems a bit weird - I can understand that at one end to fit the focuser tube but I'm a bit baffled as to what the other end is 'designed' to fit?
The optics sound promising - certainly much more complex that the simple doublet on the £50 Teleskop Express 2" version I have.
Good luck raiding the 'bits box' and even more luck trying to find some sun to test it on!

[marktownley]

New mounting cell found and made for the optics, now it all goes together in the end of the frankenquark. Clear skies to trial may well be the issue, short of a change in the forecast the weekend isn't looking too good.

[swisswalter]

Hi Mark

great to hear the TC arrived that fast. I would have been disapointed if it had just a few grams there is nothing better than a huge box of bits

[marktownley]

Bit of an update... Like I said I made a housing for the glassware, but it would not fit in any of the donor housings (an old 2" barlow, the 2" 0.5x reducer) I thought I would use as the Baader has 46mm clear aperture of glass. I got it mounted in the end in some old 2" filter cells, but the optical path was getting longer and longer, which is not what I wanted as this would increase the reducing factor, and so also vignetting and distortion / field curvature (maybe? depends what this unit is specified for). So, complete change of tactic and off I went to the Baader website for their beautifully comprehensive collection of adapters - i'd previously avoided this part of the Baader website as I knew it would set my mind awash with ideas for modding and connecting this to that etc...

The T-thread approach is the way to go, one of the 2 adapters I have ordered from China have arrived now, and this will enable me to make a T-thread to Quark connection (unscrewing the Quarks 1.25" eyepiece holder and using the 35mm thread (1.375" 24tpi). Total cost for these adapters including delivery £7

I then ordered a 2" SCT to t-thread adapter http://www.tringastro.co.uk/baader-plan ... 2514-p.asp to connect the chinese step up rings to the Baader Telecompressor.

The Other side of the telecompressor then has a 2" SCT to male m48 adapter, which allows me to screw on either a 2" eyepiece holder for visual work, or screw on a 2" to 1.25" reducer for when I put the DMK in the end for imaging. By using different accessories I will be able to vary the distance of the CCD to the telecompressor which will give me a variable reducing factor to work with. The trick is not having the reducer too far away from the CCD...

In the mean time lathe skills are being brushed up on at work and I am going to make some adapters that allow me to get
the PST in the optical train in a way that takes up less optical path than it does currently.

When I have all this assembled i'll get some pics of it all, and hopefully the sun will come out and can actually test it properly!

[grimble_cornet]

Sounds like you are having fun even without the sun - but hope you get chance to test it for real soon.
Could you point me at the Chinese adaptor which fits the Quark please? I was browsing Ebay yesterday but couldn't find a convincing 1.375" 24tpi equivalent?

[marktownley]

First one of these on the quark ep holder threads http://www.ebay.co.uk/itm/271417053357? ... EBIDX%3AIT

Then one of these in the adapter above to connect to T-thread http://www.ebay.co.uk/itm/301085479977? ... EBIDX%3AIT

Costs even less than I thought, only a fiver in total...

[grimble_cornet]

Compared to the cost of some of the stuff I have bought so far this month......

You are a gentleman

If I place an order now, it might arrive from China before my Quark clears UK customs

[swisswalter]

Hi Mark

great to hear about the new strategy. Have more fun in modding and soon a lot of sunshine

[marktownley]

Bit of an update; tried the telecompressor today, alas, as I thought in its current interim housing I did not have enough in focus (that Baader click lock Mike! ). So, until new parts and more clear skies arrive we are on hold...

[grimble_cornet]

Mmmmm...... I suspected that might be an issue

I have ordered the bits you suggested plus a few more 'rings and things' which will allow me to attach my 2" click lock to the Quark or to connect the 2" reducer I have (male 48mm one end, female 48mm at the other) directly to the Quark at one end and to the camera at the other.

I think Daystar have shipped by 'snail mail' as it has taken 4 days just to reach Chicago Airport - I may be right about the bits from China getting here before the Quark

[marktownley]

I also ordered exactly the same bits too - the male / female 48mm fittings, great minds think alike

Just wish said bits would hurry up and arrive, the 'expected delivery' from ebay tells me the bits from china are anywhere from mid march to the start of april Tracking says they have left the far east, so looks like we're back to the delay in UK customs again... I bet if crack cocaine was being shipped that would be straight through UK customs, same day delivery

[mdwmark]

Hi , the reason the Baader telecompressor has 2" male threads on both sides is that it was designed to thread into the universal mounting plate for the Solar Spectrum filter.
The idea is that it screws on the back of the filter, a 2" to T adapter screws on next. Then I would add a T extension to get it close to the new focal point. Then attach the camera with an T-C adapter.
Mark W.

[marktownley]

Thanks Mark, I can see i'm going to be ordering a T-C adapter before too long. Which way round is the reducer supposed to go? One side has longer threads than the other, my guess looking at pictures online is that that short side goes into the filter.

[mdwmark]

Hi Mark ,
Your right the short threads are the front.
Mark W.

[marktownley]

2 words - 'Newtons Rings' (with my setup)

Disappointing, because if you ignore the banding it is crystal sharp...

[swisswalter]

2 words - 'Newtons Rings' (with my setup)

Disappointing, because if you ignore the banding it is crystal sharp...

Oh no. Lately I managed to even create NR's with a 2" Barlow and a PGR CCD. It was just not placed at the right position . Don't give up Mark because of the crystal sharpness.

[marktownley]

I certainly won't give up, i've tried a few things this afternoon to no avail though.

[swisswalter]

Hi Mark

great. Take a break and a beer or two and think it over again

[grimble_cornet]

That is very disappointing and I wish I understood the physics better
As I said to Mark earlier - I get minor NR with my DMK41 plus x2 Barlow but horrendous ones with a x2.5 Powermate. As others have reported problems with the Powermate, there is obviously something in the design which 'tunes into' the NR creation process. It even gives NRs in CaK

I have never managed to see a hint of a NR with any set-up using the Grasshopper...... yet

I have a 'more basic' TS Optics TSRED052 Focal reducer x0.5 2" on loan and will try it with the Quark once the 'bits' arrive from China.

[marktownley]

Hi Mark

great. Take a break and a beer or two and think it over again

That is exactly what is happening Walter, you know me well

despite this set back there are many positives I have learned, however they are the topic of another thread...

[fjabet]

Try to tilt slightly your camera, it may be enough. Interference fringes are with reflections a real PITA in solar imaging :/

[marktownley]

Tried tilting it Frederic, found that it causes a focus shift across the fov Like you say, a PITA