Which Powermate????

[matt]

Thinking of buying a powermate but am not sure which magnification to go for?

Apart from the boost to magnification they offer for individual EPs (3x, 4x and 5x) and the need to keep magnifications to acceptable/ practicle limits are there any other factors to take into consideration which make one more preferable to another?

I'm wondering whether a scope's f ratio dictates which way you go?

What else would influence your decision?

Could I use all of them in my 8" f5 newt???

What about a Celestron C9.25?

Thanks

[Robert_T]

Hi Matt, the F-ratio is certainly important if you want to do planetary imaging through them. A 5x power mate would be good for the F5 newtonian in that case (F25 is a good f-ratio for planetary imaging), but for the 9.25 it would be running F50 and only in the most spectacular seeing and/or using a camera with large pixel size would this be viable (wouldn't let you use many eyepieces with 2350mm fl either). The 2.5x might be a good choice (I recently bought one of these) as it would give you F25 on the C9.25 (theoretically more with an extension tube) and would still give you handy additional amplification for use on the newtonian. :)


cheers,

[xrekcor]

Dont think you would use a 5x much for visual, planetary imaging it would be handy in
either the newt or C9.25 (maybe)

what focal length ep's do you have? is it for visual of imaging?

I have a 8" f/6 newt and have a 2x and a 3x I tend to use the 2x mostly even though
the 3x performs better although the 3x does get used a bit with my 14mm ep the 2x
give me and equivilent 7mm from the 14mm ep and 5mm from the 10mm ep with I use
in combination with a 3.5mm (never barlowed, not that I haven't tried) but these three
config's give me all I need for planetary, splitting doubles and smaller dso's. Haven't
heard of the 3x powermate. But if I were to get a powermate I think I would go for
2.5 times if it's for visual and a 5x for planetary imaging. But that's my setup the 5x
powermate might be getting a bit overkill on the C9.25, someone else will here will
know about that.

regards,CS

[matt]

So ... what say a 3x for using in both????

[matt]

well, that's a stupid thin to ask:lol:

Since there's no 3x Powermate!!!

Would it make a difference if I bought the 4x (2") ... with adaptor for 1.25" EPs???

Will the 2" powermate affect the viewing thru 1.25" EPs???

[xrekcor]

What are you trying to achieve? I mean is this for visual or imaging or both?
what focal length ep's do you have?

regards,CS

[matt]

Rob

Probably a bit of both with a leaning towards visual.

I've got a wide variety of EPs, but will be looking to narrow that down to three or four "bests" which I can slip into a Powermate to give me a few options.

[davidpretorius]

i am resigned to te fact that i will be buying a 2.5x for visual and a 5x for imaging ini the powermate range. I notice anthony viewing this thread so look out melbourne bintel, you better have some powermates!!!

[janoskiss]

I was going to get a 2.5x Powermate (5x is pretty much useless for visual in a 1200mm FL scope). But now I'm looking at keeping my Stratus EPs and they have FLs: 21, 13, 8, 5mm.

With the Powermate they would give effective FLs of 8.4, 5.2 and near useless 3.2mm and completely useless 2mm. So 2.5x is no good because the useful barlowed (p-mated) FLs are almost the same as those of my other EPs. I'd be better off with a 2x barlow.

That will allow me to have a two more mags to fill the gaps between the 13, 8 & 5mm and will also give a useful mag with the 8mm. And it will have to be a barlow because there is no way I'm paying $450 for a 2" P-mate. (UO 2" barlow I think. Shorty-plus is too awkward & scary with these big heavy EPs.)

My long-winded point is that what magnification barlow/powermate will suit you depends on what FL EPs you will be using it with.

[rumples riot]

Matt,

on the 9.25 the 5x needs really good seeing to use it. Still on really good nights the 5x will make mars the size of a 50 cent piece. Jupiter of course is the size of a grape fruit. No accounting for shear focal length in this regard. A powermate and and SCT work well on still nights. Like methanol and a fully worked 6. Can't be beat at times like this. ( sorry ranting - listening to Nirvana)

I most commonly use the 2.5 with both scopes being f 10. This makes Mars about the size of a ten cent piece and Jupiter about a 50mm globe. Definition is good and you don't get too much loss of definition with the toucam. When and if I go the path of the monochrome camera a 5x will achieve better results.

So I would say get the 2.5x for now, it will get the most use in an SCT. Even the 4 times will punch the image up quite large. Pity they don't make a 3x in the Powermate. I would buy it in a snap.

Best of luck.

Paul

[gbeal]

I agree with all of the above.
Visual, get the 2.5x. Imaging the 5x. In my case I do both, so ended up with both.
In the visual scene I tend to use the eyepiece rather than a Powermate and eyepiece, not sure why, but do. So............ I could live with just the 5x, and this is with scopes of about 1000mm - 1250mm focal length. In an SCT the 2.5x would be all I need.

[Robert_T]

Hi Matt, I reckon the 4x powermate might be a good single powermate compromise for you (albeit an expensive one at $470). If would give you handy f20 for the F5 and a still usable for imaging f40 with the 9.25. The 4x is next on my shopping list so can't tell you how it performs with 1.25 eyepieces, though can't see any reason why it wouldn't be fine. It would be a big hunk of glass on your focusser though so balancing might be an issue.

cheers,

[xrekcor]

I'm the same here, I prefer the straight ep look too, I figure one day I'll
will have added the 7mm & 5mm to my collection so I can toss the barlow
away from the visual part of the hobby. On clear nights the 3.5mm still
performs slighty better than the 10mm barlowed x2. I put this down to
adding the barlow, which is a Meade x2 #140 apo. It changes the
characteristics of my premium ep's (only very slightly) yet it enhances
my U/O HD's and even more so the crappy chinese whatevers that
came with my scope.

However I will get a 5x powermate at sometime... I think my planetary
imaging would benifit not having to double up barlows to get decent
planetary magnification, and less glass elements to focus and image
through. However if you are like me and you main ep's are like 14mm,
10mm, 7mm & 5mm a 2.5x barlow is going to be better to offset the
ranges of magnification where a 2x would be rather pointless. So if you
plan to fill in the missin FL's later on you may not want to spend up
large on a barlow that is temporily doing that job.

A 4x or 5x is going to be pointless or seldom used on upper mid to high
power ep's too.

So Matt, This is why I asked what FL's you have.

Regards,CS

[davidpretorius]

what type of barlow do you have???

[iceman]

Dave,


Rob,
You'll love a 5x powermate, it's much better than stacked barlows and the good thing is you can add extension tubes to increase the focal length.

Matt,
Get a 2.5x powermate, if you insist on a powermate. There are other (cheaper) 2x barlows that are 90% as good at 40% of the price. You just won't use anything higher than a 3x for visual, so I wouldn't go for a 4x powermate unless you plan on using it for imaging with the C925, as the 5x would probably be too much FL on most nights given the seeing conditions.

[bird]

Hi Guys, don't mind if I add another $0.02 to the discussion...

There are two reasons that I bought powermates (I have the 5x and 4x):

- They have removable barrels and an adapter so that I could screw the lens-portion directly onto
my filter wheel for secure attaching. The filter wheel+powermate becomes a single assembly.

- They are very sturdy mechanically, so I can hang 1 or 2 kg of filter wheel + camera off them without worrying if the whole lot will move.

The magnification (4x and 5x) is nice too, but I could get that a lot cheaper with a different barlow. The mechanical issues are more important to me.

regards, Bird

[matt]

OK

My eyepieces comprise 32mm, 25mm, 15mm and 10mm Optex plossls... and the one Vixen LV 6mm.

These will all (with the exception of the Vixen) be eventually replaced with superior quality eyepieces, though not necessarily in the same fl

Anyone care to venture which (fl) ones are likely to become redundant and which ones can be swapped for better quality eps of the same fl???

By the way, I placed an order this morning for a 2.5x Powermate:) :) :)

[ving]

you picked the right one if its visual you are after :)
congrats :)

anything bigger would be designed for taking pics.

[xrekcor]

This is how I looked at it when I went for premium ep's I already had the 2x and 3x
barlows. So I looked at the FL of the ep's I was going with which are 14mm, 10mm,
7mm, 5mm and 3.5mm. So I got the 10mm then 14mm and then 3.5mm the 2x barlow
gave me the 7mm & 5mm equivilents for now, until I can replace the barlow with the 7mm &
5mm ep's.

I think you have made the right choice, it will get more work than the others if your
a visual guy.

regards,CS

[janoskiss]

Well done! There's little worse than indecision. :thumbsup:

If you're getting a set of 3 of same design, get EPs with focal lengths that are approx. a factor of 2.5^(1/3) = 1.36 apart. For a set of four: a factor of 2.5^(1/4) = 1.26 apart.

For example: Panoptic 24, 19, 15mm + 12mm something else :confuse3:.

These combined with the 2.5 P-mate will give you a nice evenly spaced set of 8 magnifications approx a factor of 1.26 apart. Or swap the 15mm Pan + 12mm for a 13mm Nagler (the wide field will make up for having a bigger gap in mag). That is the combo I was planning on getting, but ended up going for the more sanely priced Orion Stratus EPs.

[matt]

Steve

What's that little "^" symbol mean in your equations???

[janoskiss]

^ = "to the power of".
The idea is to get an evenly spaced set of focal lengths, so that the ratio of one available magnification to the next is constant for all magnifications (except the last one of course).

[janoskiss]

Matt, once you get to try it out, Pls let us know how the Powermate is going. :)

[matt]

Will do Steve.

In fact ... had it out tonight very briefly before the clouds rolled in.

It arrived this afternoon. Very impressed with its overall quality and feel. Very nice finish and the optics are substantial with lovely subtle green coatings.

I tried out a couple of "el cheapo" plossl EPs in the Powermate, to put it to the test. I'd read claims it can help reduce problems towards the edge of the FOV ...

and yes... it did! The boost in sharpness and overall quality of view in the last 10 to 15% was well worth the extra cost.

I can't wait to really put it through its paces.

Will offer more on this when I've got mo to add:)

[davidpretorius]

this is good!!!

I am pretty set on planetary ep's 5 & 6mm, a 7 & 10 in a Pentax, Radian or vixen, but I think a powermate 2.5 would still be a worth while addition to the stable.

[davidpretorius]

pssssst matt, update your signature, you have a Televue item. Don't be too obvious about ie bragging, but make sure that "POWERMATE 2.5X" takes up 1 whole line!!!

[Robert_T]

I've only had the 2.5 powermate for a month now, but am very impressed with it's performance both visually and in imaging ... might have to offload the orion 3x barlow as it ain't getting much use anymore.

one quibble with the power mate is the screw compression ring is stiff has a "rough" action and doesn't feel the same "quality" as the rest... anyone else experience this?

[matt]

Rob

My compression ring was the same at first but seems to be getting better with more use.

Might just need a little (very carefully appplied) WD40... or just keep tightening and loosening until it wears a little and hopefully becomes smoother?

If it's any help my MoonLite focuser course focus was also a little rough to start with but has improved out of sight with use.

PS ... DaveP ... am updating the signature as we speak!!!!:lol:

[davidpretorius]

tck tck tck,


not big enough!!! its your first TV, i said not to be bragging, just god damn obnoxious.

when i get one, look out. IIS will be hacked and every signature will read "DAVO HAS A TELEVUE"

can't wait for you to post it around australia to your good mates to try. that is very kind of you to offer to do that!!!!

[matt]

No-one likes a show-off DP:lol: :lol: :lol:

Especially when my TV is just the lil' fella;)

But he's so pretty. Makes you just wanna pick him up and give him a little squeeze...

no-one else is seeing this, right?:wink2:

[davidpretorius]

just you, me and 600 other forum member and their wives and husbands!

[rumples riot]

No wife here, so only me seeing it.

[davidpretorius]

cmon rumples, i know you hug your powermates as well!!!!

[matt]

Steve H

If 3 EPs require a factor of 1.36 apart and 4= 1.26

What's the factor for 5 ... or more?

And why have I become an EP junkie?:sad: