decision time ep's

[thommo10]

I am getting some EP's for my ETX 125 I Have a Meade 4000 26mm that came with it and a Meade 2x barlow. I am thinking of the Meade 4000 8-24 zoom or a 15mm and a 6.4mm ??

[BenM]

Can't comment on Meade ep's (never used one) but I can suggest the 6.4mm is more than I would expect from the 125. I tried a 127mm cassegrain scope (celestron) and it did not do well with an Ethos 6mm. Ethos 13 was about the limit even on short range targets (without a lot of atmosphere). The optics of the scope cannot resolve anything useful at that magnification. Also, the exit pupil is so small that it becomes problematic.

I also didn't particularly like the Ethos with this scope. If I were selecting eps for it I think I would prefer Nagler or Panoptic for the longer focal lengths and Radian for the shorter. The Ethos are large eyepieces, they give barely adaquate eye relief (and no, the 6mm's eye relief is not 15mm as claimed). I didn't test others besides a cheap plossl which actually worked adquately.

On the high magnification end, I wouldn't go further than and 8mm, 10mm is probably best. On the wider field end, I would look at the field of view you get because the Ethos 13 for example gives the same field of view as a 25mm Plossl. I don't recommend the Ethos 13, but rather suggest looking at eyepieces with 68 to 82 degrees AFOV and anywhere from 16mm to 24mm. At some point, the field stop with the really long f/l ep's will result in vignetting in this scope. You can't expect to use a Nagler 31 for example. I don't know what the exact limit is, but I would start to suspect vignetting will come in with a field stop greater than 22mm. Theoretically you could go to 27mm field stop with 1.25" diagonal but the image circle on these local f/l scopes isn't that big. That's why 2" diagonals will give you nothing optically (but a better mirror may give you something). I tested the C5 with a 2" Tele Vue Everbrite diagonal. The bottleneck was definitely the cheap optics in the OTA.

[John]

Not sure about BenM's verdict on the Ethos range

I have the 13mm, 8mm and 6mm and find them superb - a small but noticable step up from the Nagler equivalents. I find the eye relief as per the makers spec.

The original posters question was on suitable eyepieces for the Meade ETX125

Firstly you don't have to stick to Meade eyepieces. The 4000 series are OK but there are better options available.

Personally I tend to prefer fixed focal length eyepieces over zooms although the Baader Hyperion 8mm - 24mm zoom is pretty good.

I think you would enjoy the views through the Baader Hyperions - they do a 13mm and an 8mm in that range - that would give you 144x and 234x, the latter being about the most you can usefully use with a 5" scope in the UK.

[michael.h.f.wilkinson]

I agree with John, 8mm is OK for the scope, but no shorter focal lengths. In fact, I just got a 10mm because the 8mm I have (which gives 250 in my 8" SCT) is often too much magnification-wise. Try to get a long eye relief one, if you have glasses (TMB planetary or clones, or Vixen NLV).

[thommo10]

Thanks for the info, I do wear specs I have slight astignatism so I can observe without but obviously better with my specs, I will have a look at the Baader Hperions and also the others you listed.

[beetlejuice]

I agree with John too. I used the whole range of Meade 4000's when I had my ETX125. I didn't use the 6.4 much as the seeing was never good enough, coupled with poor eye relief and limited field of view it wasn't pleasant to use. I most commonly used the 9.7, 15 and 20mm. They are not bad for the money (i.e. cheap) and will perform pretty well at the long focal length of the ETX, but Meade 5000's are much better optically with better eye relief and can be bought for relatively modest sums if you are on a budget. TV plossls will be very good too, though at a greater price. I've had my best views with medium fl eyepieces. Really short ones have aways been a disappointment from my urban garden.

[thommo10]

I have just looked on Sky's the Limit would the BST Explorer 18mm and 12mm be ok for my scope and are they any good.

[thommo10]

I think I have decided on the WO planetary 12.5 mm to start with. is this ok for my scope.??

[thommo10]

Ok I've took the plunge and orderd the WO SPL 12.5 ep from FLO.

[michael.h.f.wilkinson]

Sounds good. Let us know what it's like.

[thommo10]

My WO 12.5 SPL arrived today, and guess what it's RAINING !!!!!