Confusion!

[Mehraj Anik]

My second post about getting a telescope!

Thanks for all the replies and comments in here. With all your help now I am planning to get a Skywatcher Explorer 150P with EQ3-2 mount. But last night while readings some other threads, I have found another scope for the same price which is Skywatcher Explorer 150PL with the same mount.

Differences are:

1. 150P is coming with 1.25/2" CRAYFORD focuser.
   
2. Focal length (150P 750mm ƒ5 and 150PL 1200mm ƒ8)
   
3. Barlow lens in 150P and Deluxe Barlow in 150PL
   
4. Direct SLR connection in 150P and nothing is mentioned for 150PL
   
5. Tube rings and Dovetail mounting bars are coming with 150P
   

Now my questions may sound really stupid, my apologies for that. I am really new to this

1. What is the difference between Barlow and deluxe Barlow lens?
   
2. "Direct SLR connection" does this mean any other accessories that will be supplied with the package?
   
3. Why do I need tube rings and dovetail mounting bars for?
   
4. Most importantly, what would be the key differences of 750mm and 1200mm for my viewing?
   

Also just to let you know, I am not after astro-photography at this stage (Thanks for the good advices in the previous post). I might try some photos of moon, mounting my Sony alpha DSLRs, nothing more. Yet I'd also prefer the direct SLR connection thing and any other accessories related that.

Thanks

[RikM]

1. as far as I know there is no difference between a 2x barlow and a deluxe 2x barlow. I think they are one and the same thing.

2. the 'direct connection to SLR' just means the focusser has a t-thread on it so you can screw a t-ring onto it rather than use a separate adaptor. I use a separate 2" adaptor because then I can use filters as well.

3. tube rings and a dovetail bar are the 'clampy bits that attach the scope to the mount, they are common to both models.

4. the longer focal length of the 150PL means you will get a higher magnification and more contrast with any given eyepiece compared the the 150P. This means the 150PL is marginally better for planets and will tolerate cheaper eyepieces compared to the 150P. The 150P gives a marginally brighter image which means it is better at picking up faint fuzzy deep sky objects like nebulae and galaxies.

I have the 150P because my interest is deep sky and I do a bit of basic astrophotography with a DSLR. If my main interest had been planets and the moon I would have bought the PL.

Both are great scopes.

[nicnac]

ive tried the skywatcher barlow and to be frank, it was poo

if you can pick one up, i suggest the x2 TAL barlow, fantastic for the money

i dont think you will be very impressed with the EQ3 if you get the PL, it only just copes with the 150P

[RikM]

I would second that, there is nothing 'deluxe' about the SW 2x deluxe barlow.

[Mehraj Anik]

I would second that, there is nothing 'deluxe' about the SW 2x deluxe barlow.

Hahahahahaha, very well said.

I think, 150P is for me then! But just out of curiosity, as I've never used a scope before, how close moon looks with 150P? Is 150PL able to give more detailed view? Or it just magnifies with less details?

Also I was thinking, higher focal length would be helpful to go deeper sky. Why the opposite? How does it work?

ive tried the skywatcher barlow and to be frank, it was poo

if you can pick one up, i suggest the x2 TAL barlow, fantastic for the money

i dont think you will be very impressed with the EQ3 if you get the PL, it only just copes with the 150P

Thanks Nick, I will get one after I get my first telescope. I have been told about Tal barlow lenses before. Now it seems like, its a sort of "must" to have one.

[nicnac]

the 150P with a 8-5mm eyepiece, the moon will look great, remember that its the eyepiece that gives the mags, not the telescope

[johninderby]

Re: focal length pros and cons.

Take a look at this link for a very useful discussion on the subject.

http://www.chuckhawks.com/telescope_focal_length.htm

John

[Mehraj Anik]

the 150P with a 8-5mm eyepiece, the moon will look great, remember that its the eyepiece that gives the mags, not the telescope

Yes I have read about mags. Also, I found another interesting thing, which is, if I use a 2X barlow with 10mm EP, I get 5mm which magnifies even more!!

Oh one more thing, "Crayford focuser" what's good about it?

[steppenwolf]

Oh one more thing, "Crayford focuser" what's good about it?

A Crayford focuser doesn't use gears, it has a 'friction' drive which means that at the more budget end of the market, it tends to be more precise than the usual budget offering which has a rack and pinion drive (i.e has gears). As a general rule, a Crayford focuser is a good thing to have.

[johninderby]

Oh one more thing, "Crayford focuser" what's good about it?

A better quality focuser that will work more smoothly and will help with collimation as there isn't as much "slop" in the focuser. The cheap rack & pinion focusers that come with some scopes aren't exactly precision pieces of equipment. Many people replace the standard focuser with something better. Crayfords usually are dual speed with a geared down fine focusing knob on one side. One thing to watch out for though is that some scopes come with a cheap crayford that while it may be better it isn't as good as a replacement focuser.

BTW you can get a decent dual speed focuser for under £100.00.

John

[Mehraj Anik]

Re: focal length pros and cons.

Take a look at this link for a very useful discussion on the subject.

http://www.chuckhawks.com/telescope_focal_length.htm

John

Cheers matey, that was a good read!

One thing to watch out for though is that some scopes come with a cheap crayford that while it may be better it isn't as good as a replacement focuser.

John

A free Crayford Focuser is being supplied with Skywatcher Explorer 150P with EQ3-2 mount , I guess this is apparently that cheaper focuser for which I dont need to be too excited about

[Mehraj Anik]

Also I have found two terms in many threads, dont know what they mean,

DSO

Collimation

Would appreciate if someone could tell me about these!

[johninderby]

The focuser that comes with that scope is the basic single speed crayford. It is however much,much better than the old rack & pinion focuser that it used to come with.

FLO sells some replacement SkyWatcher focusers. The one at the top of the page is essentially the one that will come with your scope.

http://firstlightoptics.com/products.php?cat=120

DSO--- Deep Sky Object

Collimation---Aligning your telescope's mirrors.

John

[Astro Imp]

Also I have found two terms in many threads, dont know what they mean,

DSO

Collimation

Would appreciate if someone could tell me about these!

DSO = Deep Sky Objects, Globular/open clusters, galaxies and nebular, basically anything outside the solar system.

Collimation = getting the optics properly aligned see Astro-Baby's Guide

HTH

edit:- John beat me to it.

[Mehraj Anik]

Thanks Alan! Although I prefer John's answer. Thats what I wanted but, Alan, You gave me a whole book! Trust me thats gonna take ages to just read and understanding that ... phew! I might give up!

[Jack123456]

thanks for posting this thread.

i have been contemplating geting either the 150p or the 150pl too

I think i will go for the 150p when funds allow it

[John]

I think the 150PL is a bit undermounted on the EQ3-2 mount - high power is all very well but if the scope is vibrating, using it will not be pleasant. The shorter tube of the 150P sits more steadily on that mount.

[nicnac]

I think the 150PL is a bit undermounted on the EQ3-2 mount - high power is all very well but if the scope is vibrating, using it will not be pleasant. The shorter tube of the 150P sits more steadily on that mount.

agreed

[Mehraj Anik]

I think the 150PL is a bit undermounted on the EQ3-2 mount - high power is all very well but if the scope is vibrating, using it will not be pleasant. The shorter tube of the 150P sits more steadily on that mount.

agreed

Oh you guys are a life savers I was tearing myself between these two decisions. I was so eager to go for 150P (I get a Crayford focuser for free) which I have been suggested to be good for deep sky viewing and also a little photography! But could not get the 1200mm's magnification out of my mind! Now that I have found this wobbling problem of 150PL on EQ3-2 mount, I think I can make up my mind to order 150P finally

Wish me luck!

[nicnac]

it will do you proud Mehraj

good luck, not that you will need it

[johninderby]

I think that you've made the right decision. The shorter 150P OTA will be OK on the EQ2 mount and is a great buy.

If you' had gone for the 150PL OTA then you'd really have wanted to go for the EQ5 mount, which would have pushed the price up and the 150P is still a very good OTA.

John

[Mehraj Anik]

it will do you proud Mehraj

good luck, not that you will need it

Which one Nick? 150PL? (Sorry not really good in English)

I think that you've made the right decision. The shorter 150P OTA will be OK on the EQ2 mount and is a great buy.

If you' had gone for the 150PL OTA then you'd really have wanted to go for the EQ5 mount, which would have pushed the price up and the 150P is still a very good OTA.

John

Whats the difference between EQ2 and EQ3-2 mount? The one I am going to get, is EQ3-2 mount ... oh I know nothing!

[nicnac]

150P Mehraj

EQ3 is the big brother to EQ2

and dont worry about knowing.... it all comes in time

[johninderby]

I maent to say the EQ3 mount not the EQ2.

John

[Rich N]

My first scope was a 150p and I loved it. Really good entry level scope which gives you a lot to look at for the price. I only had to add one eyepiece (6mm) to the ones provided to satisfy my needs.