Mars Map

[Towa]

Had a go at producing a Mars map based on 40 drawings I've made

of Mars over the last two months, 16 drawings were made over the opposition weekend.

This is how the dariker and lighter areas appear in my scopes.

Scopes used and magnifications are included on the drawing.

[F15Rules]

Hi Towa,

that's just amazing detail for the aperture you are using. Are you still using the binoviewers? How do you bring them to focus in your scopes? I've just bought a pair of Burgess Binos with a x1.6 barlow. The only way I can get focus in my Pentax J80 or Celestron ED100 is by putting a x2 Televue plossl into the diagonal, then inserting the bino with the x1.6 mini barlow into the TV barlow!

It then comes to focus but I have no idea what magnification it is giving me! Help!!

Great drawings!

[Towa]

Dave

Yes, the drawings were all made with the binoviewers.

If you are using 2 Barlows then both your scopes will be producing very, very high magnification. I feel certain that you should be able

to use the bino's without an OCA in the nosepiece, if using a standard Barlow lens.

I do not use an OCA / OCS in the nose piece. Instead, I insert a shorty barlow (£25 from Ian King, but my Celestron one also works just fine) into my WO diagonal. My binoviewers are then inserted into the Shorty.

If I want more magnification, then I insert several different sized extension tubes and move then up and down until I get the right magnification.

Working out the magnification can be a real difficult job. I once saw a Maths formula for it, but the Maths were just to difficult for me.

There are some notes aboiut using barlows as correctors here:

Burgess Optical Binoviewer Focus Info

and some general notes here:

Binoviewers reviewed

I also measure the size of the planet produced in bino's and cyclops viewing. Not sure if this is the coirrect way of doing it, but the views and planet size looks the same, so I use that as the magnification on the drawing.

[Jupiter Martin]

thats a great job Towa

[philj]

Superb map Mike

Ive not used the binos yet on the Towa, (will do after mods) but I was surprised at just how much detail there was to be seen (using filters) through the Towa. For an 80mm achro its incredible.

I've been using binos on the Meade 127 Triplet for the past week on MArs and its soooo much better using 2 eyes, more natural.

Philj

[Towa]

Superb map Mike

Ive not used the binos yet on the Towa, (will do after mods) but I was surprised at just how much detail there was to be seen (using filters) through the Towa. For an 80mm achro its incredible.

Philj

Thank you everyone for the comments.

Towa 339, one of the very best massed produced 80mm Achro's ever. Apo like views for a peanuts price. I would like to buy Dave's (F15Rules) scope, but just bought a 6 inch Achro.

[DarkerSky]

That is stunning Towa. I was just thinking to myself last night what it would take to produce a map. 40 drawings over 2 months is very impressive, especially given the amount of cloudy nights through Jan. I think I have mustered about 8 Mars sketches only in 2 months

Really good work. Worthy of a POW shout I reckon

[Towa]

Thank you DarkerSky.

Looks like the map might already be out of date, just been observing with the 6 inch Achro, WOW, some very nice detail being picked-up.

Sabaeus and Meridiani apppearing as a long dark structure, at the end of Meridiani a dark fork structure easily seen (like a snakes tounge). Serpentis nicely seen slipping underneath Sabaeus. Brown surface features extending from Meridiani up towards the edge of Acidilium.

Used an orange filter and saw an extension coming out of the side of Syrtis Major.

At my last look, Meridiani and Margaritifer is producing an apex like feature. Some nice structure in the NPC band.

Great first light, stars E and F easily seen in the trapezium at 120x, plus the companion star of eta Gem. I am one happy bunny.

[dweller25]

A lot of work went into that Towa and it's amazing. Well done.

Which scope gives you the best Martian detail the 80mm achro or the 102 Tak ??

[Towa]

Hi D25, thank you.

Out of the two scopes, the Tak TSA-102 is the much better scope. If I use it with an 80mm aperture mask, then both scopes show the same major features, but it's always the TSA that reveals the more subtle low contrast markings. On double stars the Airy disk produced is much tighter with the TSA and it is quite remarkable at picking out close companion stars that are much fainter than the primary.

When used against an ED 80 APO, I prefer the view in the Towa 339. I see Planetary/lunar detail better with the 339. Had some great views of Venus last year with the 339. When the seeing is good, the magnification you can use with the 339 is quite remarkable for an Achro scope, better than the Vixen scope I had.

The 339, is a very nice grab and go type of instrument, the Tak requires a cool down period, unlike the 339 which seems to deliver the goods more or less from the word go. Because of this it was my most used scope in 2009, I could pop out and observe an object, during those moments when you seem to only get a 10 minutes break in the clouds.

When you consider that you can pick them up from car-boot sells for less than £100 (I paid £40 for mine), then they represent fantastic value for money. I replaced the focus mount with the one taken from my Evostar 120mm Achro (you have to machine an adapter flange), it is an up-grade well worth making, as it lets me use my binoviewers better.

The lens cell also has collimation screws, so you can get them bang on. A great scope for the money.