To get better views of Mars with a 250px.. New Barlow or Eyepiece?

[Tube Screamer]

Hi guys,

I had a go at viewing mars last night through my new Skywatcher 250px, and was wondering whether a Barlow on my existing eyepiece might allow me to see a little detail on the planet, or whether a higher powered eye piece would be the only answer?

I managed to snap this shot through my eye piece using my compact camera to show what I am getting now.  I'm seeing an orange/red disk, but not really getting any detail on the planet as I am with Jupiter.

Any advice would be most welcome

Russ

[AndyWB]

What eyepiece were you using?

[Tube Screamer]

What eyepiece were you using?

I was using the one that came with the scope.. I think it is 10mm, although I'm not sure what magnification that turns out to be?

[russ]

That would give 125x....not really anywhere near enough for Mars. Fine for Jupiter and Saturn. You really need to be aiming for 200x+.

As the 10mm that came with the scope is the weakest part of the package, i would recommend another eyepiece, not a barlow. Something around 6-7mm would give close to 200x. A 6mm or 7mm Orthoscopic would give the best view for the money. Or one of the TMB Planetary eyepieces at the same focal length.

Another option is a zoom. There are some good ones around these days, the Baader being the most popular (but pricey). I have a Seben 8-24 zoom which is absolutely cracking. Same eyepiece as the Skywatcher and Celestron 8-24, 100% identical (ignore what some dealers may say). It works well with a barlow. We use it with the GSO 2.5x barlow, so it becomes a 3.2-9.6mm barlow. A whole range of different planetary options now available. It won't provide the same view as a 6mm Orthoscopic but its still very good. The pair cost £80 new.

[ronin]

Reads as 1200mm FL so you would be getting 120x with the 10mm

Mars generally needs more.

Would say a 5mm but that means your thoughts will turn to the 10mm and the barlow you have.

The combination may not be that good, however since you have both sat there give the pair a try.

Costs nothing other then about 5 minutes.

A 5mm will give you 240x, which 5mm is up to you, normally people go for the BST Starguider or the Celestron X-Cel.

A 6mm would give 200x.

You are going to need to spend money on eyepieces, if your barlow were OK I would half suggest the BST 5mm and 12mm. That would give a 5mm and a 6mm when barlowed. The celestrons have smaller increments, so you could look at their 5mm and 7mm and forget a barlow.

Last time round Mars gave people a lot of anguish.

About 1 in 4 managed something.

[kerrylewis]

Whatever equipment you use, Mars is an unforgiving little blighter! To see any detail requires excellent seeing conditions and lots of patience. If the seeing is very good it will take magnification but otherwise it's a waste of time. A red or orange filter may help bring out the contrast in any details if the conditions allow it.

I usually try it for half an hour or so and if it's still 'orange fuzz ball' time then I go elsewhere and perhaps come back later to see if things have improved.

[russ]

Would say a 5mm but that means your thoughts will turn to the 10mm and the barlow you have.

The combination may not be that good, however since you have both sat there give the pair a try.

Costs nothing other then about 5 minutes.

I read it that he was thinking of buying a barlow rather than already had one. My mistake. 

[Tube Screamer]

I read it that he was thinking of buying a barlow rather than already had one. My mistake. 

Thanks for all the response guys.  No you were actually reading it right Russ, I was thinking of purchasing either a Barlow or eyepiece for the purpose of getting better views of Mars, and possibly other planets too.  I maybe didn't word my question very clearly.

Thanks

Russ

[Reeny]

I use a Barlow - but I always wonder if I would have better views with a straight 6mm eyepiece, instead of using 2x 12mm.

You need decent gear whichever way you go.

I have a £30 Skywatcher 6mm which is OK in the 3-inch travel scope - but struggling in the 200p dob.

A Barlow will place more glass between you and the target.

Hopefully my next purchase will be a 6mm Delos to replace the cheap n cheerful Skywatcher.

[russ]

Russ, i think i would stand by my original statement (except the wrong mag, it should have been 120x). The 10mm is a poor eyepiece, would be waste to buy a barlow to use with the 10mm.

As Ronin suggested, the BST Explorer is a good eyepiece and relatively cheap. If only buying one eyepiece i would have reservations about recommending the 5mm though. 240x is not a power you can use on a regular basis. Saturn and Jupiter struggle to take that much except on the best of nights. However, the 12mm BST with a barlow would be a useful combo. Give you a good medium power eyepiece for galaxies etc and also a good planetary setup giving 200x.

I also stand by my original recommendation of the zoom and barlow. When the funds are low they make a lot of sense. You won't get the ultimate optical quality but the good ones give a very acceptable image. And you have a very large collection of eyepieces at your disposal with all atmospheric conditions covered.

[cotterless45]

I use a 5.5 Meade 5000 in 1200mm ota's.

However there's a lot more than gear.

Wait until it's high enough to give a decent view. Getting comfortably seated helps.

Keep both eyes open and shield your non observing eye.

Don't stare of try looking hard, just relax and expect to give some time to the view.

Newts are planetary killers , provided that collimation is spot on. It can be thrown out by tube flex , especially in trusses and vast temperature changes. I check with a Barlowed laser when observing to tune it accurately.

Filters will not enhance a poor view. A good view will be helped by trying a filter that suits you. I use a 23A light red to enhance the view. We've seen the polar cap and Syrtis Major this year and are looking forward to April,

Nick.

[kerrylewis]

Agree 100% with Nick. My earlier post sounds a bit negative on reflection(!) but what I was trying to say is better put by Nick. Of course you need the right gear and it needs to be 'tuned' properly, but in the end it will come down to the seeing. Even at its best Mars presents a small disc and the detail on it is obviously even smaller still. However, as Nick's chart shows, we'll all stand a better chance next month.

Good luck

Kerry

[AndyWB]

I have the 5mm BST, and x240 is too much, really. At the moment I'm feeling a real gap between the 5mm and 8mm BST, which I'm considering filling with a 6mm ortho, specifically for Mars - I'm just a little worried about the narrow field of view. At x200 it would fair whiz across the eyepiece.

[russ]

I have the 5mm BST, and x240 is too much, really. At the moment I'm feeling a real gap between the 5mm and 8mm BST, which I'm considering filling with a 6mm ortho, specifically for Mars - I'm just a little worried about the narrow field of view. At x200 it would fair whiz across the eyepiece.

You get use to it, the extra nudging is not too bad. I have a 7mm Antares Ortho and when i'm in the right mood i don't mind using it. But if feeling a bit tired i really can't be doing with it. Much rather sink my eye socket into comfortable rubber eyeguard and a big chunk of glass.

[John]

I was using 180x, 225x and 257x on Mars the other night with my ED120 refractor. The low altitude made it a challenging target but those magnifications, even the higher one, gave a reasonably crisp image with some details visible on the disk. I was using the 3-6mm Nagler zoom and 5mm and 3.5mm Pentax XW's. The latter in particular are superb for this task but they are expensive options.

[AlexB67]

I have the 5mm BST, and x240 is too much, really. At the moment I'm feeling a real gap between the 5mm and 8mm BST, which I'm considering filling with a 6mm ortho, specifically for Mars - I'm just a little worried about the narrow field of view. At x200 it would fair whiz across the eyepiece.

Andy. I currently got my hands on the 5mm BGO recently I'll let you know how I get on after a few more goes in the 10 inch. I mainly used it in the heritage on Moon and Jupiter so far and find it really impressive the way it performs. I also used the TV 6mm radian to compare a bit, despite the mag differences I can tell some things about how they differ and why these little orthos are so good started to become clear after not long viewing.  

I did have one brief look at Mars with it too in the 10 inch, this was over the weekend some time, and dispite the magnification step from 200 to 240 the BGO stil showed a bit more on the contrast front, though at that mag conditions were not good enough to tell apart some of the other characteristics in terms of sharpness, but it was a bit more defined how the darker regions on Mars stood out with it in the BGO over the Radian.  

I can't say too much about it right now in earnest, since in the 10 Dob 240x is often pushing given Mars is still quite low and I am waiting for a good moment,. I have  not even done Jupiter yet with it in the bigger scope either, hopefully this evening, there will be a GRS transit at around 8:30.

I can say though that in the Heritage the dinky little BGO showed its worth already

[Moonshane]

the challenges with Mars are generally:

• currently at at a low elevation but not too bad when due south at opposition in a month or so
• it is small so you either need to accept a very small but sharp view or a larger a fuzzier view - the detail is still visible at higher magnifications, just less aesthetically pleasing
• it is bright so you need to stare longer and/or use a filter (I use a Baader Neodymium) and/or high magnification to tone this down - I also use an off axis aperture mask on my 16" dob

all that said, there's something rather special about seeing even blurry detail on the surface of another planet - Mars is the only planet where this is possible (other than Earth of course!). as with all planetary observing, ensure you are well cooled (at least 5 minutes per inch of aperture), well collimated and seated to get best results. I found 200-300x the best for Mars at last apparition.

[AlexB67]

I find an hour minimum on the 250 SW is needed to start getting good performance on planets at 200x ( assuming seeing conditions allow it ), it still can better after that, but by that time it is getting pretty close to being a lot more settled  and I am ready to start slapping in that powaaaaaa and enjoy  A fan would help  and speed that up no doubt.   I tend to just put the scope outside well before I start often times, but leave the  lids on, then a bit before take them off and start on some other lower power stuff. Having it outside before hand helps to shorten that cooling/settling period from the point you start observing.

[johnd]

Really interesting reading the vast practical knowledge on here. I saw Mars on my first night with my new 12" Dob and just to see a disk shape with slight colour differences was a WOW for me. May be I'm easily pleased but it does wet the appetite for wanting good seeing conditions.

One question, I have a “Baader Classic Q 2.25x Barlow” and a 12” BST EP, would I see an object better with a dedicated 5-6mm EP or is it minimal in terms of seeing difference?

[Charic]

Haven't studied Mars properly yet, too many obstructions to contend with, but have seen the  orange! The 8mm and 12mm BST's are fine. I just love the 8mm, my first purchase. 

Just recently, my best ever viewing of Jupiter with the transit shadow of Io, was observed using the 5mm and 1.5x Barlow ( just the lens from the SWD 2xBarlow directly attached to the EP )The shadow was just perfect in my eye. But the 5mm does need the better viewing conditions, so where do you go, the 8mm or the 12mm ? These EP's  put you one step either side of the 5mm. For practical use I would say the 12mm Barlowed would be the better, more practical option, and the 8mm Barlowed on those better nights. The longer focal lengths  give a slightly better eye relief. I did try the 6mm  TMB Planetary II but the FOV was tighter than the BST's

[Moonshane]

the seeing conditions will have a much more pronounced effect on the view than the method used to achieve a magnification. personally, I prefer single eyepieces, manly due to weight considerations and faffiness.

[andrew63]

From my experience with 'challenging' targets less is always better. By less i'm thinking of the simplicity of the eyepiece -  unless you go big budget. A plossl or ortho will give the best view. A 6 or 7mm ortho will give you more than a BST, UWA clone, hyperion etc. Better colour fidelity, less stay light - crucial with Mars as the detail is small and contrast subtle, and generally a bit sharper resolution wise. I used a 6mm ortho with 6" reflector on mars for several years which gave up good detail at X200.

A 6mm BCO orth for £50 will give you about as good a view of mars you could get - atmosphere depending.  The 6mm Vixen for £109 that John is reviewing sounds a great alternative if budget permits. In fact the new Vixens could be a great overall choice as a planetary eyepiece given the extra comfort factor, which is important given the time and patience that Mars observing requires !

andrew

[bingevader]

I have the 5mm BST, and x240 is too much, really. At the moment I'm feeling a real gap between the 5mm and 8mm BST, which I'm considering filling with a 6mm ortho, specifically for Mars - I'm just a little worried about the narrow field of view. At x200 it would fair whiz across the eyepiece.

I know what you mean about the gaps at high magnification!

I can recommend the 6mm WO SPL in an 8" 'scope. Slightly wider FOV and longer ER than the ortho and a good bright EP. Brighter than the 7mm X-Cel LX to be honest with you. I wish they did a few more focal lengths!

Also, I don't have a problem with things whizzing across the FOV either, it's been great on Jupiter when the seeing has been good.

As people have already said, sticking a barlow on a reasonable EP would be fine, (I do it on the moon).

I've yet to see Mars through the 8" 'scope! But I was always delighted and amazed at being able to see the polar ice cap throught the etx90!

Cheers

[Moonshane]

I have many more eyepieces at higher power than lower power

http://stargazerslounge.com/topic/188794-eyepiece-groups/

[Reeny]

According to my "captains star log" - I saw the detail on Mars for the first time at 240x a few weeks ago using the 11mm Explore Scientific 82^o, and a 2.2x Barlow.

In a 250PX, the equivalent eyepiece size would be 5mm to give you 240x without the Barlow.

I recall that the seeing conditions were spectacularly good that night. With Mars located dead South, high above the horizon.

I could clearly see a dark grey patch in the shape of Africa, but missed the white ice cap.

next time maybe.