Tak Extenders -v- Televue Powermates

[sharpiel]

Have posed this same question to a couple of individuals here but am seeking the experiences of the wider community who have used both and can give their thoughts:

Tak sells the TKA31595 Extender-TOA 1.6X (will be discontinued) for $444 or the TKA37595 Extender-ED 1.5X (FSQ-85EDX/TSA/TOA) also for $444 or I can get a Televue PM 2x or 4x 2" for $399 (Bintel price).

I want to use the PM for my TOA 130, 12" SCT and Lunt 60. I assume the Tak extender will only work on the Tak TOA. Is there such a compelling difference in the quality of the Tak extender that I would need to buy it specially for the Tak or will I be happy with the more versatile TV PM?

[PRejto (Peter)]

You also might want to consider this by Astro Physics:

http://www.astro-physics.com/index.h...ducts/products

Reasonably priced and certainly does a fine job. I took these images of M83 and M16 using this product and my TEC140:

http://www.pbase.com/prejto/image/152287993
http://www.pbase.com/prejto/image/152783100

As for the Televue products I've usually just seen these used for planetary photography. For DS targets you might be better off with a specialised product. For DS targets I can't imagine you would want to use a 4x barlow. Once you push your scope to near f14 you will pay a big price both in guiding difficulties and image capture times. 1.5-1.8 seems a quite decent range to operate in.

Peter

Peter

[Dennis]

Hi Les

Check the physical interface of the Tak Extender. I have the Tak x1.6 Extender for my Mewlon 180 and as you can see in the attached photo, it has a raised glass element at the “camera” end of the unit.

I have found that all my Tak accessories have a well-designed and solid physical interface with each other, which makes sense as I guess that they are designed as an overall, integrated system.

The 3rd party Barlow’s may well be as good optically and will likely fit physically, but the metal work, cut outs and locking screws on the Tak accessories are all solid and match each other which is a nice feature.

I also have a Tak x0.8 Reducer and I find that it does not sit well with some non Tak accessories, in particular focusers that have a brass compression ring. The ring does not clamp the Tak barrel securely due to the machined design of the barrel of the Reducer. My Tak Extender has a longer 2” insert so does not suffer from this problem.

I also have several TV PowerMates and they are excellent optically and mechanically but not designed specifically for the Tak idiosyncrasies, which may or may not, be a problem.

Cheers

Dennis

[sharpiel]

Thanks Dennis.

I completely understand the mechanical interface reference. All the other Tak accessories I own fit beautifully with each other.

Have you used the Tak extender on other non Tak scopes and with what result/comments. And likewise the TV PM on the Tak.

I'm trying to avoid buying both the Extender and a PM to use across a range of scopes if possible without optical/mechanical problems.

Cheers

Originally Posted by Dennis

Hi Les

Check the physical interface of the Tak Extender. I have the Tak x1.6 Extender for my Mewlon 180 and as you can see in the attached photo, it has a raised glass element at the “camera” end of the unit.

I have found that all my Tak accessories have a well-designed and solid physical interface with each other, which makes sense as I guess that they are designed as an overall, integrated system.

The 3rd party Barlow’s may well be as good optically and will likely fit physically, but the metal work, cut outs and locking screws on the Tak accessories are all solid and match each other which is a nice feature.

I also have a Tak x0.8 Reducer and I find that it does not sit well with some non Tak accessories, in particular focusers that have a brass compression ring. The ring does not clamp the Tak barrel securely due to the machined design of the barrel of the Reducer. My Tak Extender has a longer 2” insert so does not suffer from this problem.

I also have several TV PowerMates and they are excellent optically and mechanically but not designed specifically for the Tak idiosyncrasies, which may or may not, be a problem.

Cheers

Dennis

[Dennis]

Hi Les

I have used the Tak Extender x1.6 and Televue PowerMates on my Mewlon 180 and Celestron C9.25 for long focal length, high resolution imaging of the Sun, Moon, Planets and double stars.

Although I have not conducted a formal analysis of the results, I do recall that I was very satisfied with both the Tak and TeleVue Extender/Barlow.

Bear in mind that this genre of photography usually uses a webcam with short exposures where 100’s of frames are stacked to capture those moments of “lucky” seeing.

I cannot really comment on long exposure deep sky applications.

Cheers

Dennis

[Dennis]

Hi Les,

I thought I would follow up with the following observations.

I have the following in my collection:

• Tak x1.6 Extender (2 inch)
• Televue x2.5 Powermate (1 ¼ inch)
• Televue x4 Powermate (2 inch)
• Televue x5 Powermate (1 ¼ inch).

I think that I have only used the TV x4 and x5 (on my C92.5) less than 5 times in the 5 years I have had them. The seeing conditions just do not support the use of these on my Mewlon 180 and C9.25 ‘scopes although they have been useful for splitting double stars.

So, at my native focal lengths of 2160mm and 2350mm it comes down to the Tak x1.6 and TV x2.5 If the best accessory is the one that you use the most, then my Tak x1.6 Extender gets far more usage than my Televue x2.5.

If you want to explore high resolution lunar and planetary photography such as is being posted by the top practitioners on IIS, then you may need the TV x4 or x5, ideally a 10”-16” aperture instrument and the dedication to chase down those moments of exquisite seeing. I think these hi res wizards often operate at effective focal lengths of 10,000mm to 16,000mm and use good (expensive) cameras.

Of late I have found that the conditions have seen me shooting at the native focal length of my ‘scopes and only occasionally have I been able to use the Tak x1.6 with the TV x2.5 remaining in its box as I haven’t really synchronised my imaging sessions with the good seeing that supports its use.

As mentioned previously, on the planets and the moon I haven’t seen any noticeable difference between the Tak and TV units that can be differentiated above the image quality limitations placed on me by the local seeing conditions.

Cheers

Dennis

[dennisjames1]

Hello Dennis from another Dennis

I was thinking of buying a powermate X4 to use with a Meade 8 inch SCT, for Planets imaging with a Canon 700d. This will be all first time trial and error, but i am gathering that the 4X maybe too much not usable ?? What would you suggest eg Mars ?

cheers

Dennis

[Dennis]

Originally Posted by dennisjames1

Hello Dennis from another Dennis

I was thinking of buying a powermate X4 to use with a Meade 8 inch SCT, for Planets imaging with a Canon 700d. This will be all first time trial and error, but i am gathering that the 4X maybe too much not usable ?? What would you suggest eg Mars ?

cheers

Dennis

Hello, Dennis

This maybe a difficult question to answer satisfactorily as I don’t really have any insight into what you want to achieve or how serious and long term your intentions are.

If you aspire to produce the world class results of the top planetary imagers on IIS, I would encourage you to look at their images and see what equipment and techniques they use as I don’t operate in that rarefied place!

In my case, I enjoy astronomy to my own personal level of engagement and I don’t have the motivation or desire to invest myself to that degree. Therefore, the TeleVue x2.5 PowerMate is an appropriate Barlow but at focal lengths of 4000mm plus, you will need excellent seeing, good technique and a smattering of good luck with seeing conditions.

You also need to "read" your local seeing conditions to know when you can deploy those longer focal lengths, as in my experience, those nights are few and far between.

I have never used a DSLR for high resolution lunar or planetary imaging so I can’t really comment on the suitability of the Canon DSLR.

Most high resolution lunar or planetary imaging folks use webcams which seem to be the de facto standard.

A lot of the magic happens in processing the captured frames. I am constantly amazed when a gorgeously detailed image, with beautiful tones, pops out at the end of an image processing session using free software such as AutoStakkert2!, AVIStack and Registax as some examples.

Cheers

Dennis

[dennisjames1]

Thanks Dennis

Yes I'm just looking to take small steps, see what happens and hopefully not get too frustrated with it,life is short .

I have seen a couple of results with Mars on Space Weather with a Celestron HD 8 and 4X Powermate, might ask the guys at Bintel too, see what they say.

All trial and error and not wanting to break the bank

cheers

[Dennis]

Just to provide some sense of image scale, here are examples of a close-up of a region of the Moon, overlaid with images of Mars and Saturn, all taken with the same set up - Tak Mewlon 180 F12 and Tak x1.6 Extender at an effective focal length of 3456mm.

I have shown the close-up lunar region on a full moon disc so you can better understand the size differences between these bodies.

Cheers

Dennis

[sharpiel]

Nice pics though!