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Big Brother of my Kowa TSN-99a (1 Viewer)

paperweight

Well-known member
Since I sold the AYOdigi II mount and am waiting for the same model with encoders and an Argo Navis controller to arrive next week, I concentrated on putting the 99a to a series of tests with both eyepieces (TE 11 and TE 80).
At daytime, I felt the TE 80 delivers a bit more contrast than the TE 11, but the later is a very fine and versatile eyepiece as well.
Tonight I watched the moon and Saturn with the TE 80 and two Kowa 1.6 extenders (resulting in about 100x magnification). Both objects were rewarding, but it's no surprise the Takahashi TOA 130 was far superior even at 200x.
At 100x, finding Saturn with the 99a took some time, and digiscoping with the DA4/DA10 adapters plus the Sony RX 100 II is not much fun at that magnification rate because fixing the camera on the adapters at a perfect angle with the scope is hard enough in daylight.
But the moon was of course easier to catch at 100x. I had forgotten to bring my USB cable release, so there might be a bit of blur due to 1/60 shutter speed (1600 ISO).

DSC02369.JPG

I'm offering the two 1.6 Extenders for sale because for birding and daytime observation the 70x of the TE 11 will do for me, and if I want higher magnification I might come back to the Kowa astro adapters and choose an eyepiece from my line of Pentax XW. I guess an XW 7 or 5 might work fine with the 99a.
 
Still rehearsing and trying to get some routine with the Kowa 99a and the TOA 130. There are so many things to take care of and to have in mind when working in the darkness.
I have just done two pictures of the 99a and the TOA. It's not that I really want to judge, I'll keep both instruments anyway. I used a Pentax XW 7 eyepiece (resulting in 143x magnification) on the TOA and the Kowa TE 11 Zoom eyepiece with two stacked Kowa 1.6 extenders on the 99a. I tried to find the matching magnification by twisting the zoom to an estimated 56x to achieve 143x.
My "camera" was my iPhone 6s in a Kowa TSN-IP6 Photo Adapter which of course did not fit the diameter of the Pentax. So I had to somehow hold it in place.
This is no serious comparison. There is a lot of air movement at the moment (25° C) and I do hope the air will be cool and calm later on to allow me a look at Saturn in the South around 11pm.

TOA 130

View attachment 1461347

99a

View attachment 1461348
kowa extenders can be stacked? didnt know that
 

paperweight

Well-known member
@countryman george : yes, it's easy. You screw off the plastic collar of the first extender you have placed in the scope and screw in the second one.

Since I'm waiting for my new mount for the Tak at the moment I did some observation with my Kowa 99a and the TE-80 40x. In the first session two nights ago, I concentrated on Aqualia, and last night I admired Cassiopeia with her star clusters where she meets the milky way.
Even if the full moon came in at around 10.30 pm and sent some unwanted light, it was quite an experience. The 99 plus TE-80 are such a fine set for a walk in the sky.
When and if I can use my Tak in about a week's time, I guess the Televue Panoptic 41mm (25x) and the Pentax XW30mm (33x) will get more time than the Pentax XW 5 and 3.5. I'm thinking about getting a set of OIII filters (2" and 1,25") to be able to discern nebulae more easily. I guess there will be no OIII filters available for the Kowa eyepieces, so in the end I will sell my Kowa extenders and get the two astro adapters available for the 77, 88 and 99 line of scopes.
 

wllmspd

Well-known member
Depending on the eyepiece you could put the filter on the eye end, need something to hold it in place and you’d need to well shield the view as otherwise you’ll end up just seeing a reflection of your eye as the views are darkened. There will be a roll off of filter performance towards the edges of the field as they are not designed to perform for such a wide range of incident angles, but the central area will be fine. I have to do this approach with binoculars that have fixed eyepieces.

Peter
 

paperweight

Well-known member
Thanks @wllmspd . I guess it will make more sense to invest in adapters (cheap) for my eyepieces (Pentax XW and Televue Panoptic) because I will be able to use them in turns and screw them in.
I'm looking forward to comparing the TE-80 (40x) with 80° FOV to my Televue Panoptic 41 (25x on my Tak) with 68° FOV.
All in all, I guess I will prefer walking along the Deep Sky with low magnification rates to using high magnification on planets. My TOA 130 can do up to 300x in good conditions, and one thing I would like to see is Jupiter with its red spot and the moons.
Last night, with the moon rising next to Jupiter who came later, I could see four moons, but not a lot of details of Jupiter itself because of the moonlight.
 
@countryman george : yes, it's easy. You screw off the plastic collar of the first extender you have placed in the scope and screw in the second one.

Since I'm waiting for my new mount for the Tak at the moment I did some observation with my Kowa 99a and the TE-80 40x. In the first session two nights ago, I concentrated on Aqualia, and last night I admired Cassiopeia with her star clusters where she meets the milky way.
Even if the full moon came in at around 10.30 pm and sent some unwanted light, it was quite an experience. The 99 plus TE-80 are such a fine set for a walk in the sky.
When and if I can use my Tak in about a week's time, I guess the Televue Panoptic 41mm (25x) and the Pentax XW30mm (33x) will get more time than the Pentax XW 5 and 3.5. I'm thinking about getting a set of OIII filters (2" and 1,25") to be able to discern nebulae more easily. I guess there will be no OIII filters available for the Kowa eyepieces, so in the end I will sell my Kowa extenders and get the two astro adapters available for the 77, 88 and 99 line of scopes.
Oh good to hear, does quality degrade when you stack both kowa extenders? And for the night sky i have no idea how to map anything. Is it possible to see those clusters with only 60x?
 

paperweight

Well-known member
@countryman george : no, quality does not degrade. The quality of the lenses is superb. Of course the exit pupil gets smaller just as it will with a 3.5mm eyepiece. I would not sell my extenders if I did not have those astronomic eyepieces that can be used on the scope with adapters.
Concerning star clusters I'm not experienced enough to say which magnification you will need, but maybe others who are can help with your question.
 

Binastro

Well-known member
Star clusters vary from tiny to large.

The Pleiades is perhaps 2 plus degrees, The Hyades larger.
Alpha Persei cluster large.

There are some very small clusters apparently in or next to large clusters.

So some need 7x50s others 100x.

My 123mm rich field scope covered most from 16x 4.7 degrees, 20x 3.2 degrees to 145x 15 arcminutes.

Globular clusters can be tiny and need a large telescope.

Planetary nebulae can be tiny and need well over 100x.

Just saw a very good drawing of Saturn from New Zealand in 1951.
He used 200x and 435x with a 127mm Watson refractor with a Watson Conrady objective I think.

Regards,
B.
 

Binastro

Well-known member
Hyades open cluster 5.5 degrees across.

Praesepe or Beehive 1.5 degrees.

Double cluster 0.5 degrees.

Many well known large clusters 0.5 to 1.0 degrees across.

Fainter clusters further away can be much smaller.

Globular clusters from 0.5 degrees to very small for distant globular clusters.

That is in our galaxy.

If one goes to M31 then clusters are apparently very small.
But large telescope needed and maybe just available to stacked digital images.

B.
 

Binastro

Well-known member
Alpha Persei cluster 6.1 degrees across.

The Coathanger is 1 degree across, but not a true cluster as the stars are not associated with each other, just a pretty asterism.

B.
 

paperweight

Well-known member
@Binastro : thanks for the detailed list. With my Kowa 99a, I might go up to 200x, but, as you pointed out, the beauty of nebulae and other objects beyond our galaxy will only come alive with hours of exposure to digital cameras.
I think there's huge difference in approach between people who hunt for nice pictures and people who just like to observe (like me). A while ago, I was offered a used Takahashi TOA 150 with a complete set of flattener, reducer, camera, filters, goto mount etc. When I saw the refractor in a photograph I was shied away by how complicated it looked with all those cables and instruments.
To me, it looked just like a patient in hospital treated with intensive care.
 

Binastro

Well-known member
In a dark sky both the Kowa and Takahashi will show a lot of deep sky objects visually.

Star clusters are quite good in these instruments. also globular clusters.

M35 has a smaller cluster within it but further away.

200x is only useful on planets and double stars.

For other objects 20x to 100x is sufficient.

A friend only uses binoculars, monoculars and spotting scopes.
None are very big, but he observes almost daily or nightly.
He uses only low or medium magnifications.
He has posted many thousands of observations.

Another friend uses 185x on a 90mm refractor or 100mm Maksutov for planets, but he is very experienced.
I am surprised at the detail he sees and the quality of his drawings, more like paintings.

Regards,
B.
 

paperweight

Well-known member
For a while, I had been asking myself if I needed both instruments, the 99a and the TOA 130, and the answer is ......definitely yes.
Meanwhile, I have acquired a s/h AOK Swiss AYOdigi II with built in encoders and an Argo Navis computer and can honestly recommend this mount for anyone who is interested in using his 883 or 99a for astronomical purposes.
The two star alignment of the Argo Navis is easy to do, and the 99a is on the AYOdigi II in a minute, using a Vixen style dovetail bar.

For lenghty sessions at night and with enough time (about 15 minutes)to set it up, the TOA 130 with the finder scope and the Telrad finder will be my choice. If the sky clears unexpectedly at night the 99a will be ready in less than 5 minutes.
 
Question, past 70x is tsn 99a with the extender still usable in terrestrial viewing? Im thinking about the more magnification for the far future but dont know if it's worth.
 

paperweight

Well-known member
@countryman george : the 99a works absolutely fine with the TSN-EX 16 extender on both my eyepieces (TE 11 and TE 80). Even if I stack both my extenders I find the result very satisfying. If I'm too lazy to carry my TOA 130 outside or if I just have an hour in between at night, the extenders offer a brilliant look at planets and constellations. At 102x (99a, TE 80, 2x EX 16 stacked) the problem is not the object you want to watch: it's rather finding it. I recommend the Telrad finder or "star-hopping". Simply pointing the scope at the chosen object was a frustrating experience: you cannot really search the sky with 100x.
The reason I'm selling one or even both my extenders is that, at almost 72, I mostly use the 99a for birding from my porch or garden within a radius of 100m and don't really need more than the 70x magnification the TE 11 offers on the 99a. If I still did birding at longer distances (coast, flat land) I would definitely keep them.
 
@countryman george : the 99a works absolutely fine with the TSN-EX 16 extender on both my eyepieces (TE 11 and TE 80). Even if I stack both my extenders I find the result very satisfying. If I'm too lazy to carry my TOA 130 outside or if I just have an hour in between at night, the extenders offer a brilliant look at planets and constellations. At 102x (99a, TE 80, 2x EX 16 stacked) the problem is not the object you want to watch: it's rather finding it. I recommend the Telrad finder or "star-hopping". Simply pointing the scope at the chosen object was a frustrating experience: you cannot really search the sky with 100x.
The reason I'm selling one or even both my extenders is that, at almost 72, I mostly use the 99a for birding from my porch or garden within a radius of 100m and don't really need more than the 70x magnification the TE 11 offers on the 99a. If I still did birding at longer distances (coast, flat land) I would definitely keep them.
Good to know, FOV is very small as i expected, with both extenders i would assume that the brightness is cut down by a big percentage?
 

paperweight

Well-known member
@countryman george: That will be for you to decide. I have never regretted investing that money. I had the 883 before I bought the 99a and have never been disappointed.
Concerning astronomy, I think magnification is not as important as I thought before I started. Most nights you will find me working with magnifications between 40x and 100x even if my 3.5mm eyepiece will provide about 286x.
 

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