mn 56

[vince 66]

I have been toying with the Idea of buying a Intes micro mn56 I like the size for portabilaty and it comes in a case so its easier to get past the wife . The thing is with it being 127mm dia with a central obstruction of 30mm will get any more from it than I get with my megrez 90 not sure if this is correct but to my reckoning I would have the equivelent of 97mm dia would this be correct?.

[Peter Drew]

Hello Vince.

I have a MN56 and find it to be excellent optically and would be more than a match for a 4" Apo. The 30mm central obstruction is almost negligible, although technically it results in a small loss of contrast you still have the benefit of 127mm resolution. The downsides to this telescope are a lengthy cool down time if it's been kept in a warm environment and it's quite heavy. For performance per £ it's hard to beat.

[AndyH]

The MN56 has been one of those scopes I've always wanted to get one day. I adored my M500 Mak-Cass, but always thought I should of got the 5" MN instead.

Never, every read a bad review.

I noticed a while back, Widescreen Centre had knocked £200 off the asking price.

Are these available anywhere else in the UK? Do House of Optics(UK) sell direct to the public?

Cheers,

Andy.

[John]

I have an Intes MN61 (6" F/5.9 mak-newtonian) which has a 29mm central obstruction. It's a superb scope which certainly outperforms my Vixen 102mm ED refractor by a noticeable margin - it's reputed to be able to compete with the best 5" apochromats, which I can well believe.

They don't have the glossy finish of the William Optics scopes but are excellently engineered and optically of very high quality.

[jam1e1]

John, how does your MN compare to 250 newt/120ED in terms of when would you use? (understand flatter field and apeture considerations).

was thinking of getting one in the future, interested to see how it would fit in as have 250 and 120ed also

[John]

I've only had the ED120 a month and I've barely managed 30 mins under the stars with it and no "back to back" observing with the MN61 of course so it's too early to have formed opinions I think.

The 10" newt goes deeper as you would expect but I prefer the views through the MN61 of planets and double stars - it really does emulate a quality refractor in that respect and even slightly outperformed my old Meade AR6 / Chromacor combination (which gave close to 6" ED refractor performance I reckon).

I'm expecting the ED120 to push the MN61 very hard although the latter should have the edge on DSO's. As the colder weather draws in the refractor will cool more quickly so could be more convenient to use.

So early days and I'll post more "findings" when the clouds let me

[jam1e1]

thanks, interested to hear when the opportunity comes about.

For me the 'grab and go' of ed120 appeals, if the views of MN do compare more favourably will certainly consider another purchase or replacement

[Whippy]

I have been toying with the Idea of buying a Intes micro mn56 I like the size for portabilaty and it comes in a case so its easier to get past the wife . The thing is with it being 127mm dia with a central obstruction of 30mm will get any more from it than I get with my megrez 90 not sure if this is correct but to my reckoning I would have the equivelent of 97mm dia would this be correct?.

MN56's are a cracking scope. I can't remember the exact formula off hand but you don't simply subtract the aperture of the secondary mirror from the aperture of the main. It's to do with area and in this respect, the result is a small percentage of loss in regard to light gathering ability. I would be confident it would outperform your Megrez 90.

The MN56 will sit on an EQ5 without any problems, anything smaller and I think you'll run into issues I think. It is small but I would recommend you buy the metal dewshield and it then becomes a little bit long but it's still small enough not to be unwieldy. I've never had issues with cooldown with any of my scopes but then they're kept in an outhouse so they're close to ambient already.

Tony..

[Alma]

The MN56 will easily out perform the 90mm scope - particularly on planets and the Moon at which the MN56 will beat just about any similar aperture refractor (trust me on this one - I have an outstanding f6.2, 97.8 Strehl APM 105mm refractor and the MN56 I used to own was marginally better at lunar visual observing). However the refractor will be a much better wide, rich field instrument - the MN56, despite being f:6 suffers from its relatively small secondary which means that a wide field eyepiece of more than about 20mm focal length will experience loss of field illumination (only the central part of the lens will be illuminated by the secondary; the outer part misses the secondary and focuses on the tube wall surrounding it). For the price though the MN56 is superb value!

[Alkaid]

Ok, here's where I am confused. I looked at Widescreen Centre's site whereby both the MN56 and MN58 are for sale.

They say and I quote:

Please choose the F/6 models for planetary and wide field applications and the F/8 models for visual and photo imaging.

Isn't this a contradiction? Aren't planetary and widefield applications a world apart? I would have thought the short F6 ratio better for widefield and imaging, the longer focal length F8 model better for planetary use and just visual.

[Whippy]

Yeah, that's not how I would put it, that's for sure.

The 56 can bring cameras to focus but due to the small secondary it hads a small illuminated field, a starlight xpress H9/atik 314L would be alright but anything bigger will suffer from vignetting. If widescreen imported the MN55/65, they might be better with their larger secondaries but I've never seen one in the UK. I guess there's the f6 'photo' Mak-Casses to consider too.

Personally, I'm not sure about an f8 MN. My understanding is that the longer the focal ratio of a newtonian, the less coma there is so while at shorter ratios (F4-F6) there's a distinct advantage but less so with a f8 model.

Tony..