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Night Vision Newbie - 4 inch refractor, Help, Lost in Space

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#1 laico

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Posted 28 September 2020 - 04:11 AM

I have been involved in the hobby for the past 30 yrs, I understand no one telescope is going to Master all things, there is always that option to improve on all parameters from aperture to speed etc. I have searched high and low and put forth the due diligence, I have read all of Eddgie's articles to comprehend the methods, caveats, and hardware options. I have noticed a consist theme, that being the evolving choice of hardware/telescopes. Herein is my dilemma, my wife will shoot be at sunrise should I buy another telescope, I currently have a stock (no FT) Takahashi FC-100DF 2.7 focuser / F/7.4 to F/4.9 (Takahashi FC-35 "expensive" focal reducer which I currently do "NOT" own). I have enjoyed the scope immensely for Visual, no regrets, only drawback is driving great distances to get further away from New York City lights (White zone). Its time for me to modernize and evolve as so many CN'ers have done before me. I have read so many varying opinions that I am confused by the possibility of me being able to utilize my current 4" refractor. I understand some of the math, I understand "scale", imaging, framing, the self explanatory aspects to what some might opt for larger versus modest views. In my neck of the woods anything is an improvement so my expectation is both rational and practical.

 

To my question, I had read a review posted online about the TNVC, 55mm plossil, all married to a "Televue 85mm refractor" got me thinking; how the hell did it go from F/7 to F/1 or F/2 to achieve the speed, what math is involved here? I understand as is the case in this hobby we always achieve best results with more aperture and speed, its a never ending battle however, how do we work with what we have without always having to reinvent the wheel with a fast NEWT or some other astrograph. I realize the FC-100DF 4" refractor as designed for Visual in the ideal world where dark skies were consistent.  My objective is to try and utilize with a MOD 3 but I am uncertain as how to accomplish with "decent' expectations, For the price of the Takahashi Focal Reducer I could just as well by something more cost effective, so to my original question could someone Please explain how we increase the overall speed, considering the 85mm out of the box is an  F/7 focal ratio by product design. 

 

The How to is the part that is missing. My initial expectations with a 4" refractor would be to make out nebulae, let alone galaxies i.e. M51. Is it possible to transform this FC-100DF, I do not mind being the pioneer, to date I have not found a single syllable that someone might have posted. Its one hell of a refractor under pristine skies, I would think their is someone that can educate myself how to work with what I already have. I digress, I realize one scope cannot do it all, but surely it can be versatile enough to configure to meet reasonable expectations. Any advice is welcome, I apologize for reiterating here and there but I just wanted to be for certain I was not misinterpreted, and I thank all for replying.

 

Thanks,

 

Joe


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#2 nimitz69

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Posted 28 September 2020 - 07:10 AM

You don’t really need to do anything ...

MOD3C - 55mm Plossl - Ha filter or band pass filter - focal reducer (.8/.75/.5 all likely come to focus in that refractor - scope .... done

Edited by nimitz69, 28 September 2020 - 07:11 AM.


#3 laico

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Posted 28 September 2020 - 07:36 AM

Hi Nimitz,

 

Thank you for your reply, my  concern was whether a 3rd party focal reducer would work versus the over priced Tak reducer. So your saying try and given the extra back focus the DF model has it should come to focus. Again thanks for the reply, my confidence with experimenting over the years has been up and down with trying to work out configurations that seemed simple from the onset only to add up to $$. Again thank you, I sincerely want to be able to achieve NV with "reasonable" expectations on this refractor without being overwhelmed. Thanks again. Joe



#4 bobhen

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Posted 28 September 2020 - 07:55 AM

I use a Takahashi TSA 120 (with the focuser extension removed) with an Antares .7 reducer and an Astro-Physics 2” diagonal with my intensifier at PRIME focus (no eyepieces in the stack). This reduces the scope to around F5.25. All comes to focus and I get to use the less expensive 1.25 filters versus the 2” filters.

 

I also use a 102mm F5 achromat. With the .7 reducer the scope gets down to around F3.5. You will need to use filters with an achromat but you will be using filters with an intensifier anyway.

 

To give you an idea, below is how I setup the intensifier at PRIME focus on the 102mm achromat. From left to right…

 

1. The refractor optical tube
2. A GSO 2” focuser. I needed to use the GSO focuser on this refractor to shorten the OTA
3. An Astro-Physics 2” diagonal (these have short light paths)
4. Optional: An Antares 2” .7 reducer (the reducer screws onto the bottom of the 2” to 1.25” adapter that comes with most diagonals or can be bought separately)
5. The 2” to 1.25 adapter that comes with most 2” diagonals
6. 1.25” filter (Ha or Pass) 6 or 7nm Ha filters are popular, 685 pass filters are popular in heavy light pollution
7. C-mount to 1.25” adapter (screwed onto the nose of the intensifier) to use the intensifier at PRIME focus
6. The NVD Micro Intensifier

 

Bob

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#5 laico

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Posted 28 September 2020 - 08:23 AM

Hi Bob,

 

Thank you, I had read your posts earlier and saved the image train photo, "you" are the sole individual that posted anything related to a refractor, I had a TSA120 yrs, words fall short of the scopes ability to deliver, sold it a year ago before the NV bug took hold and opted for the 100DF. I had setup a an 8" newt for a friend using MOD3 prime focus and was amazed at what could "now" be visible in New Jersey (half hour from NYC). I was about to the pull the trigger on another scope when I thought to myself somebody has had to achieve success without going for their lungs on that expensive Tak Focal Reducer. I value everyone's insight and knowledge, what confused me most was the posts regarding speed, who says minimum of F3 vs who says F/10 on an SCT is works just fine, at some point given the overall costs and God knows I have been there done that, as I noted a vote of confidence from those who have respectfully put in the time and money to have helped us Newbies. It is greatly appreciated, To reiterate I read your posts earlier and was thankful that you opened the door to my initial question. I would love to hear from someone that has configured  NV with a Tak FC-100. Bob, having only looked through the 8" newt and was awestruck, I would think your 102mm 4" delivers as well, for me success would be to see nebula that in the past were just a smudge and a "few" simple Messier galaxies that are fundamentally simple to find. I realize 4" will always be a scaled back image with limited DSO but I would think your results justify the expenditure. One last point, the 4" on a DM-4 is nothing short of simple, evenly matched and proportionate, the thought of having to acquire an 6"/8" newt defeats the present setup, Again, thank you very much for taking the time to assist and educate myself, Thanks... Joe  



#6 jay.i

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Posted 28 September 2020 - 11:39 AM

Funny enough, Bob is the first person I can remember seeing talking about using a NVD with a refractor as well! I didn't even know NV astronomy was a thing until I saw a photo of Bob's TSA-120 with the NVD Micro in it. Thanks Bob!

 

Joe, you don't need the expensive Takahashi reducer. You can get a relatively cheap GSO reducer (try this one) for a little over $100. The upside to this reducer over the now-hard-to-find Antares 0.7x is that the GSO has filter threads while the Antares does not. This requires you to put the filter on the diagonal, if yours is threaded, or on the eyepiece when doing afocal. Most diagonals are threaded so that's not really an issue. If you buy 1.25" filters, you can thread them into your 1.25" nosepiece, but then you need to buy more filters in the 2" form factor for afocal use (which I recommend to get really bright images from your relatively slow refractor). I'd recommend buying 2" filters and a step-up ring from PVS-14 to 2", if you want to use 2" filters with an ENVIS/PVS-14 objective. I have a Computar 50mm f/1.3 lens that has a 2" filter adapter and I'm glad I bought 2" filters so I can use this lens filtered. I vastly prefer it over my ENVIS lens as I appreciate the additional image scale. It's just a bummer that 2" filters are so much more expensive than 1.25" - all part of the expensive package that is NV!

 

I hope this helps!



#7 Jeff Morgan

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Posted 28 September 2020 - 12:04 PM

The upside to this reducer over the now-hard-to-find Antares 0.7x is that the GSO has filter threads while the Antares does not. 

 

Perhaps the specs on the Antares have changed over time.

 

My Antares 0.7x reducer most definitely has a forward M48 (2") filter thread. 



#8 gatorengineer

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Posted 28 September 2020 - 12:16 PM

I had a Gen 2+ for a while and got my Gen3 PVS-14 a couple of weeks back (world of difference), have only had it out a few times due to bad weather, but it is truly amazing.  I have so far used it at 50MM, 80MM and 24", I haven't gotten it into the either the 7" or 8" Maks or the FSQ, but I can see from my couple of nights that aperture is still important as is speed.  If you already have a DM-4, I would think seriously of an 8" F4 newt, at 4x the light of your 100, and afocally many stops faster, I think this would be a better scope in roughly the same out the door difficulty as your 100 refractor. 

 

If you are going Afocally at any time bite the bullet and get 2" filters, and go for Baader or better.

 

Of course you can always start where you are and adjust as well.  I am thankful for NV to give me back the hobby in my suburban location.



#9 jay.i

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Posted 28 September 2020 - 01:47 PM

Perhaps the specs on the Antares have changed over time.

 

My Antares 0.7x reducer most definitely has a forward M48 (2") filter thread. 

Everywhere I look, I see that it threads into diagonals and anything that has 2" filter threads, but it does not have female threads for a filter in front. The ScopeStuff page specifically states this. Maybe it has changed but this is definitely a downside for new buyers.



#10 Jeff Morgan

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Posted 28 September 2020 - 02:45 PM

Everywhere I look, I see that it threads into diagonals and anything that has 2" filter threads, but it does not have female threads for a filter in front. The ScopeStuff page specifically states this. Maybe it has changed but this is definitely a downside for new buyers.

Just looked at the ad - it has changed!

 

My older (2016) Antares has a deeper cell, male threads camera side, female threads telescope side.



#11 jay.i

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Posted 28 September 2020 - 03:41 PM

Just looked at the ad - it has changed!

 

My older (2016) Antares has a deeper cell, male threads camera side, female threads telescope side.

Well shucks. It'd be nice to have a little extra reduction over my 0.75x GSO but I'm not going to chase down an old Antares just for that.



#12 laico

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Posted 28 September 2020 - 05:53 PM

Thank you to "ALL"

 

Jay thank you for reminding me about the Antares focal reducer, I recall it from years ago as a popular choice and thanks for reassuring myself, I just cannot justify the cost of the TAK FR given my expectations.

 

Gator thank you, for pointing out my concerns about aperture and grounding my expectation, this is the primary reason for my post, to hear from others that might engage in a spirited debate, to hear from individuals that have used the 4" primarily and were either dissatisfied or content, I have reminded myself time and time 4" is just 4", but would welcome feedback that have had measured success.

 

Jeff, thanks for your input, I had read the many posts that you to have contributed to NV. Have you any advice as to pursue the 4" or as Gator suggested go larger if you want a measured response to justify the expenditure. The most consistent remarks in "all" posts seems to be today its this and tomorrow its that, today 6" was it but months later now its 8", I realize its all "subjective" my concerns are like everyone else who took the first step, I would still welcome to hear from anyone in CN that has praise for the 4" refractor/NV combination. I know what I cannot see in my White Zone,I know at Cherry Springs Park, PA what I can see, and that is the question at hand, does NV on a 4" deliver the same goods, is it a 50% improvement or is it marginal.

 

A sincere thank you to all who have replied.

 

Joe



#13 gatorengineer

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Posted 28 September 2020 - 06:17 PM

From earlier posts a link to Mikes Page that lets you set up a spread sheet to rough out your equipment.    See Mikes Nov 17th post

 

http://www.loptics.c...ightvision.html


Edited by gatorengineer, 28 September 2020 - 06:17 PM.


#14 gatorengineer

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Posted 28 September 2020 - 06:39 PM

oh and on what you can see, I just got my Russel Optics 65mm plossl today and its mostly clear.  I took my NV handheld Spyglass 80MM F3.75  (Effective focal length 1.5 in NV terms)Stellarvue straight through finder out with it in and the Antilia 3.5nm on it and could easily see that North American at astronomical twilight with a mostly full moon rising.  so in short NV Rocks....   


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#15 laico

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Posted 28 September 2020 - 06:57 PM

Hi Gator,

 

Thank you for the link, I had acknowledged that particular persons compassion and motivation to enjoy more of the hobby, he had posted his personal experiences, for those that have gone the distance, spent the money, dealt with the pitfalls and triumphed we all owe a debt of gratitude to. Having said that thanks for the feedback with NGC 7000 with the 80mm. NGC 7000 is one big target, I apologize I should have cited a simple example, lets take M57 the Ring Nebula, I have seen this in dark skies and was not at all disappointing, in my White zone its dam near impossible with out without a filter/averted vision, at some point you start imagining you glimpsed it. However, is that an object that would be obtainable on par with a dark sky experience.Thank You again for your effort in assisting my inquiries herein, greatly appreciated.

 

Joe



#16 jay.i

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Posted 28 September 2020 - 07:37 PM

Hi Gator,

 

Thank you for the link, I had acknowledged that particular persons compassion and motivation to enjoy more of the hobby, he had posted his personal experiences, for those that have gone the distance, spent the money, dealt with the pitfalls and triumphed we all owe a debt of gratitude to. Having said that thanks for the feedback with NGC 7000 with the 80mm. NGC 7000 is one big target, I apologize I should have cited a simple example, lets take M57 the Ring Nebula, I have seen this in dark skies and was not at all disappointing, in my White zone its dam near impossible with out without a filter/averted vision, at some point you start imagining you glimpsed it. However, is that an object that would be obtainable on par with a dark sky experience.Thank You again for your effort in assisting my inquiries herein, greatly appreciated.

 

Joe

I stumbled into the Ring with my little FS-60CB (at f/5.9, prime focus) and found it intriguing though small. With an FC-100DF you'd get just enough magnification to make it interesting. I only barely noticed it as I was scanning around and saw something that looked like a star but too big/defocused to be a star.

 

In my experience, the amplification of light from NV is something like 2-3 stops, or 4-8x as much light. Views from my white-red zone (~SQM 18.5) were similar to what I had seen in my club's green-blue zone (~SQM 21.3) with no NV. I think you will be surprised what can be seen, if you take the leap. And, if you drive to even a moderately dark site, even more surprised.



#17 The Ardent

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Posted 28 September 2020 - 07:48 PM

Joe I hope you don’t mind me adding some input. For visual, the Tak refractor is hard to beat until you double aperture. For NV, a simple and cheap 6” Newt will be better IMO, like the Astrotech 6” imaging newt. For a couple of reasons 1. NV at prime focus will give a correct view that matches naked eye / binocular view. 2. Will give a native f/4 without reducer 3. No chromatic (infrared) aberration, although I never tested this with the Tak refractors In short , I never used NV with the refractors. For NV It was either Newtonian aperture, or small lens portability. Most bright nebulae are visible with the tiny stock lens supplied with NV devices. I went camera lens crazy and ended up with this sorta smallish, fast , 4” refractor . It’s almost perfect for NV , but poor at overhead viewing . https://www.cloudyni...8-at-dark-site/
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#18 laico

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Posted 28 September 2020 - 11:07 PM

Hi Ardent,

 

I welcome the suggestions and your input which helps immensely, thanks for framing the doubling aspect as it relates to my particular refractor. I had the newt on the back burner hoping someone would chime in as it relates to this FC-100DF.

 

So forgive me if I misinterpret your sentence where you note either NEWT or small lens portability, are you saying some people use the MOD 3 ©  with a telephoto camera lens, and accomplish favorable results with such small aperture? I noted the many examples of CN posts regarding simple camera lens being used and "NO" telescope whatsoever. I understand any object nearing the zenith would be a strain on ones neck but am I correct in interpreting that some simply use a camera lens and hand hold or use as binoculars? Without going of on a  tangent, has that yielded equally satisfying views when compared to the telescope setup?  Thank you again for acknowledging my initial post, much appreciated.

 

Thanks,

 

Joe



#19 Jeff Morgan

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Posted 29 September 2020 - 12:03 AM

Jeff, thanks for your input, I had read the many posts that you to have contributed to NV. Have you any advice as to pursue the 4" or as Gator suggested go larger if you want a measured response to justify the expenditure. The most consistent remarks in "all" posts seems to be today its this and tomorrow its that, today 6" was it but months later now its 8", I realize its all "subjective" my concerns are like everyone else who took the first step, I would still welcome to hear from anyone in CN that has praise for the 4" refractor/NV combination. I know what I cannot see in my White Zone,I know at Cherry Springs Park, PA what I can see, and that is the question at hand, does NV on a 4" deliver the same goods, is it a 50% improvement or is it marginal.

 

A few things to consider:

 

1) Don't sell your 4" Tak short. It would make a great NV scope! 

 

I spent a year using a Canon 300mm f/2.8 telephoto, which is essentially a 4" refractor. Views were amazing. With the Tele Vue 67 Plossl used afocally, your Tak would put up similar performance. The difference is with the Tak you can add a 0.7x reducer, go prime focus, and a use a Powermate (or two) to provide range of magnifications - the telephoto is quite limited in that respect. And the whole star diagonal thing!

 

2) NV does not cure aperture fever. What it does for small apertures is truly amazing - but after a time you take the next logical step: "Just think what it could do with a big aperture!"

 

Whether or not you go larger you can figure out in the fullness of time. But in the Here and Now, the Tak will be great.

 

NV delivers the goods on pretty much everything except reflection nebula, because the spectral response of the technology is falling at those wavelengths. It can see blue, but not very well. Maybe not even as good as the human retina. I want to make a concerted effort from my dark site before I finalize that determination. In any event, there are really only a handful of those objects in the sky (and I can still observe them with my regular eyepieces). Everything longer than blue benefits.

 

NV does even better in dark sky locations because the intensifier is not simultaneously boosting light pollution, so the benefits are even greater. Glenn LeDrew explains it here:

 

https://www.cloudyni...n-i3/?p=3549132

 

3) The overlooked factor is the added opportunities to do astronomy. When you have the option of doing useful, satisfying observing from home, you do more of it.


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#20 GeezerGazer

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Posted 29 September 2020 - 12:14 AM

I have read so many varying opinions that I am confused by the possibility of me being able to utilize my current 4" refractor.  Joe, you have a fine refractor, and as you write, no single scope can do it all.  But, NV will help you see more with what you do have.  However, it is a reality that most of us using NV have more than one optical system.  With your scope, NV will help you see most DSO's, including open clusters, globs and galaxies better.  The only time you will necessarily be concerned with reducing the FL of your TAK is for emission nebulae using H-a filters.  First, most nebulae are big... too big for most optical systems, so a reducer provides a bigger FoV.  Second, the narrow, pass-band filters reject so much light, that a faster optical system becomes necessary to prevent photon starvation... which results in electronic noise that we call scintillation.  I have successfully used a TEC 140 f:7, a TAK 100 FC-DL f:9, an ST 120 f:5, a TV-60 f:6, and a VersaScope (60mm finder) f:3.8 with my NVDs.  They have all provided satisfying views.  Your TAK should do just fine.  But understand that if you begin to concentrate on emission nebulae, you will want to improve the image you see, which means you will likely try another optical system with potentially faster focal ratio.  Here is a link to a thread about telescope options for use with NV that might be of interest to you:  https://www.cloudyni...nv#entry7782592

 

To my question, I had read a review posted online about the TNVC, 55mm plossil, all married to a "Televue 85mm refractor" got me thinking; how the hell did it go from F/7 to F/1 or F/2 to achieve the speed, what math is involved here?  There are two ways to reduce your refractor, both of which have been described above.  One is using a dedicated focal reducer which can be used in both prime or afocal mode.  The second way is to use a long focal length eyepiece in afocal mode.  In afocal, you can use both, a focal reducer and a long focal length eyepiece in conjunction.  Let's say you are using a TV 55 eyepiece in your TAK, with a 27mm objective lens (1x) on your NVD in afocal.  The eyepiece creates a focused image, which the NVD, with its own objective, looks into.  Because the NVD objective lens has a FL very nearly half that of the 55mm eyepiece, it acts as a .5x reducer.  If you add a .7x dedicated reducer to the optical chain, it also provides additional reduction in the FL, and thus the focal ratio, of the optical system.  Essentially, your scope is f:7 x .5x = f:3.5, x .7x = f:2.45 which is plenty fast enough to use a narrow band filter for emission nebulae.  If you plan to use NV in afocal, primarily with your TAK, you might consider the TV 55 with the 67mm adapter, which by itself, provides .4x reduction, putting your TAK at f:2.8.   Keep in mind that refractors, like other types of optical systems, have limitations.  It is likely you will see at least mild vignetting with such a system, and depending on the optical accessories, curvature and/or astigmatism can show up in the outer FoV.  But the results will be worth the effort.  You will be able to see things in real time you have never seen before.  And when you do travel to a dark site, you will be more amazed than ever.  

 

Here's a good link to fully appreciate the differences between afocal and prime use of an NVD:  

 

This is a 2018 observing report, including phone photos, using two refractors: https://www.cloudyni...l=city of rocks

 

The How to is the part that is missing... I would think their is someone that can educate myself how to work with what I already have.  Descriptions have already been shown in responses above.  Probably the first question you need to answer is whether you will need the versatility of a C-mount NVD for prime or if you will only use the NVD in afocal.  Each mode has strong points and drawbacks.  I use prime almost exclusively, but I keep an afocal system for occasional use.  And rather than reducing my refractors, I chose to reduce an f:4 Newt to f:2.8 for nebulae, which for me, was a good decision for many reasons.

 

​Finally, you might want to PM CNer simoneb who uses NV in your white zone and can tell you about his experience under your conditions. 

Ray

 

 

 

 


Edited by GeezerGazer, 29 September 2020 - 12:19 AM.

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#21 laico

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Posted 29 September 2020 - 06:05 AM

Hi Jeff, Hi Ray,

 

Jeff....  your superb line itemization and brief synopsis nailed it for me, rather than cull through more posts, your vote of confidence has had a positive outcome, the 4" is here to stay and will be the benchmark for what I can achieve with it, I will further document my results so others can benefit, and I thank you sincerely for the time you put forth to educate myself so I could understand, to reiterate a sincere Thank You.

 

Ray..... your ability to articulate the math regarding the Televue 85mm nailed it, I was able to deduce how it was accomplished, the initial read left out any presence of a FR, its absence or me overlooking that sentence was actually good thing because your explanation further broadened the scope (pardon the pun) of understanding how one could tweak the overall hardware to exact a specific speed, etc. I have always understood the basis for FR, Barlows, calculations but what I did "NOT" know is precisely what you pointed out regarding the speed that could be attained. My math was missing sadly some of the fundamentals that I had never calculated, so for me it was a good learning experience, I thank you sincerely as well.

 

Finally, in summation to all that replied I thank you likewise for all of your replies, they all helped immensely and were all very positive, I was able to learn and process that in a manner that served me well. A sincere Thank You to all that chimed in and I am fully satisfied that I will be content with any outcome going forward.

 

A final thank you to CN for having so many good member and their willingness to lend a hand, that is hard to find in this 21st century, it is surely a testament to the many members and their desire to help all, let alone their patience.

 

Thanks,

 

Joe


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#22 bobhen

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Posted 29 September 2020 - 08:39 AM

for me success would be to see nebula that in the past were just a smudge and a "few" simple Messier galaxies that are fundamentally simple to find. I realize 4" will always be a scaled back image with limited DSO but I would think your results justify the expenditure. One last point, the 4" on a DM-4 is nothing short of simple, evenly matched and proportionate, the thought of having to acquire an 6"/8" newt defeats the present setup, Again, thank you very much for taking the time to assist and educate myself, Thanks... Joe  

Most any scope will work with NV. It’s really about image scale. Fast delivers a wider field but smaller objects in that field. Slow delivers a narrower field but the objects within are larger. Slow can show more scintillation but that depends on filers and sky conditions as well.

 

A 4” reasonably fast refractor will really impress with NV. I can’t even list all of the objects that were previously invisible or nearly so that are now visible with NV. You will definitely gain a new perspective on the Milky Way galaxy – even from New Jersey. Objects like the Horsehead Nebula, Flame Nebula, North American Nebula, Heart and Soul Nebula, California Nebula, Monkey Head Nebula and many other objects will be visible from your white zone backyard.

 

Use the Tak for a while, with a reducer and Barlow and with filters of course, and then you will have a better idea whether you want to add something that will deliver more image scale to complement the Tak or not.

 

For small objects, like most galaxies, I added a C8 for more image scale, which works great at F7 and F10 on most galaxies, globular clusters, etc. The C8 is so light and compact that it easily rides on the same mounts as my other scopes so there was no portability penalty.

 

Have fun.

 

Bob


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#23 nimitz69

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Posted 29 September 2020 - 10:19 AM

I am opposite most here as I use my NVD almost exclusively on my 14” f/4.6 Dob. My 4” APO triplet refractor is setup for imaging in my observatory. I don’t get the wide sweeping views but the first time you see the Ring nebula or M13 with a 14” aperture is hard to forget. Ive been debating getting a short, fast refractor but I have so few viewing days due to weather its hard to justify at the moment. Maybe net summer when i’m Finally retired for good and don’t mind waking up in the middle of the night for an hr or two of clear skies at 2am but not now. Like others have said, just use what you’ve got and then later if you want more scale you can always go bigger ....
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#24 The Ardent

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Posted 29 September 2020 - 12:43 PM

NV can mirror visual observing in some respects. For visual, I either use my largest aperture (dob) or smallest (binoculars) 

This is the reason I sold my 100 DF. It was stuck in the middle. 

 

NV with a camera lens can give 1x, 2x, 3x..up to a magnification range overlap with small telescope. Various c-mount and vintage camera lenses are easily available, take your pick.  When it's handheld 7x NV , it's very similar to using 7x binoculars . Handheld NV is good for going outside for a bit, looking around, and going back in without the hassle of setting up a tripod /scope. Same reason binoculars ar so popular with astronomers. And just like binoculars, too much magnification is subject to handheld shake. 

 

Astronomy my has long benefitted from trends in the photography world. Your Tak refractor lenses exist today not because of astronomy, but due to photographers 50 years ago demanding apochromatic lenses from Canon, Nikon and the like.  Once they got theirs, it was simple to use the same R&D, factories, and labor to make telescope lenses. 

Recently the mirrorless cameras sparked an industry of adapters to marry vintage lenses with today's cameras. Luckily for us those adapters include the c-mount that Night vision uses, so we can benefit from a wide variety of cheap vintage lenses. 

 

In today's astronomy world imaging has taken over, and that means short, fast telescopes and lots of h-alpha filters. NV     benefits again. 

 

Ask yourself this question : When was the last time you saw the Horsehead nebula from your backyard with a 4" scope under light polluted skies? Well you can with  NV. Is it worth it ? 

Hi Ardent,

So forgive me if I misinterpret your sentence where you note either NEW Without going of on a  tangent, has that yielded equally satisfying views when compared to the telescope setup?  Thank you again for acknowledging my initial post, much appreciated.

Thanks

Joe

 


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#25 Dale Eason

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Posted 29 September 2020 - 03:37 PM

 

 I understand any object nearing the zenith would be a strain on ones neck but am I correct in interpreting that some simply use a camera lens and hand hold or use as binoculars? Without going of on a  tangent, has that yielded equally satisfying views when compared to the telescope setup?  Thank you again for acknowledging my initial post, much appreciated.

 

A name for that has been coined by Mike Lockwood and we call it NV neck.  It is caused by the glorious views of using NV  and looking up at the Cygnus area during summer here in the US.  Not being able to pull yourself away is a common complaint.  Lawn chair is a big help.

 

Using only the NV with a 35mm camera lens attached to it's front.  Usually giving you 1 to 3x splendid views of things from your city drive way that you thought you could only see with a large scope and a dark site.  "Equally satisfying"  does not come close to describing it.  It is astounding to see so much in the field of view.  I use NV hand held that way and Afocal with a scope (usually a 10 inch F3 dob).  Each has their own appeal for different reasons.


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