What is Reddit's opinion of Oumij1 Monocular Planetary Eyepiece Black Metal 1.25 Inch Monocular Astronomical Telescope Accessory SWA 58 Degree 4mm Planetary Eyepiece?

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6mm & 3x would be too much for seeing and optics (625x), even 500x doesn't gain detail really and things get dim.

The HR Planetary eyepieces cost $23-$30 via Aliexpress, some are even on Sale via Amazon, https://www.amazon.com/Oumij1-Monocular-Planetary-Astronomical-Telescope/dp/B08CY2ZZ8K

4mm will give you over 300x, The 3.2mm perhaps (~390x), which will work if seeing is excellent (and that is rare).

The HR Planetary have a 58° apparent field of view. The planets will move through the field very quickly though at those magnifications and the afov.

As you are building your telescope, you could build an equatorial platform for the dobsonian though ;-)

> light pollution

True, the exit pupil will be quite large and the sky background makes observing DSO difficult.

But finding stuff is always an issue, even if you observe at higher magnification later. So the 32mm Plössl is something you should consider. Even that is a relatively narrow field of view compared to a 2" 70° or 82° eyepiece for example!

Star clusters are a bit easier to observe, but you'll always benefit from a dark sky :-)

Do you have other telescopes as you have the Barlow already?

I have this lens specifically, which is just a tiny step up. It's also pushing the edges of what your telescope can handle as far as magnification, can be touchy to focus.

But with it, you can see multiple dark bands on Jupiter, and slightly make out the red spot. And that's in a rather light polluted area. The 6mm you might be able to add a 2x barlow lens down the line to see a but larger, but that's absolutely not possible with this lens (130p has a max magnification of 260x, you just won't see better than that).

https://smile.amazon.com/dp/B08CY2ZZ8K

Hi :-)

Mars is a tough one, even in larger telescope.

It's tiny, so the 10mm kit eyepiece just doesn't cut it either. A decent 4mm would help. On a budget, a HR Planetary clone, 58° apparent field of view, is a nice eyepiece to have. Do not get short 4mm Plössl due to unusable eye-relief and avoid the cheap 4mm 62° sold everywhere.

The 4mm 58° costs <=$30 via Aliexpress, <=$50 via Amazon or Agenaastro. Better ones would be the Dual ED or even the Explore Scientific ultra-wide-angle for example, depending on your budget.

Avoid barlows. Cheap ones reduce the contrast, good ones cost more than the above eyepiece.

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Simulations,

http://blog.pixelgiraffe.com/wp-content/uploads/2020/06/fov-150-750.png

http://blog.pixelgiraffe.com/wp-content/uploads/2015/11/awb_Heritage_Magnifications_small.png

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The 3.2mm HR Planetary might work for the Heritage 150p, but it pushes your luck regarding common atmospheric seeing conditions, and probably the optics... while only getting you a bit larger image, not much more detail gained overall. I know it sucks, but while it seems like you need more magnification, it's often best to stick to a moderate magnification and keep observing, you can still spot a lot of detail.

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You can use a simulator to estimate the scale of things, e.g. https://www.sternfreunde-muenster.de/ocalc.php

https://astronomy.tools/calculators/field_of_view/ is also very, very good, but only as calculator. It does not estimate the relative apparent field of view and doesn't stop you from choosing magnifications that are way too unrealistic.

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Random 4mm 58° links,

• https://www.amazon.com/Oumij1-Monocular-Planetary-Astronomical-Telescope/dp/B08CY2ZZ8K/

• https://agenaastro.com/bst-1-25-uwa-planetary-eyepiece-4mm.html

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Clear skies :-)

Hello :-)

4mm would work fine with this telescope. Even though a short 6" reflector has some down-sides compared to the longer 6" dobsonians, 4mm (187.5x) is still within reason.

In the smaller 130p I use ~160x and even a bit more at times.

Field of view / Size comparison simulations,

• http://blog.pixelgiraffe.com/wp-content/uploads/2020/06/fov-150-750.png

• http://blog.pixelgiraffe.com/wp-content/uploads/2015/11/awb_Heritage_Magnifications_small.png

The 3.2mm HR Planetary might work for the Heritage 150p, but it pushes your luck regarding common atmospheric seeing conditions, and probably the optics... while only getting you a bit larger image, not much more detail gained overall. I know it sucks, but while it seems like you need more magnification, it's often best to stick to a moderate magnification and keep observing, you can still spot a lot of detail.

You can use a simulator to estimate the scale of things, e.g. https://www.sternfreunde-muenster.de/ocalc.php and https://astronomy.tools/calculators/field_of_view/ is also very, very good, but only as calculator. The later does not estimate the relative apparent field of view and doesn't stop you from choosing magnifications that are way too unrealistic.

Random 4mm 58° links,

https://aliexpress.com/item/32724445552.html (China)

https://www.amazon.com/Oumij1-Monocular-Planetary-Astronomical-Telescope/dp/B08CY2ZZ8K/

https://agenaastro.com/bst-1-25-uwa-planetary-eyepiece-4mm.html

These are sold from various sellers and brands. No-name, Skywatcher, store-brands... Check seller/Item ratings.

For the price, they are some of the best budget eyepieces. They have longer eye-relief than short Plössl and are way better than the cheap 4mm 62° eyepieces you can find all over the place (I find it quite useless, tried one as it was only $8).

You can of course get better eyepieces. Starting at the more expensive dual-ed 60° eyepieces, and up to the Explore-Scientifc 82° eyepieces for example. But if you don't mind the smaller afov, the 58° aren't half-bad! I've Teleskop-Express store brand ones and am quite pleased with them.

Clear skies :-)

Hi :-)

Neat! What eyepieces do you have?

Start with the longest focal length eyepiece (20mm-25mm). It will give you the largest overview (field of view).

For planets you can use higher magnifications (shorter focal length eyepieces.)

(Telescope focal length divided by eyepiece focal length = magnification. But more means a dimmer image).

Try aligning the finder during the day at a very remote target to minimize parallax. (Avoid the sun! Permanent eye damage).

Practice focusing, movement.

The image will be upside-down, which is normal for reflector telescopes.

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Here are some starters;

• How to align,

• How to use an equatorial mount

Grab a copy of "Turn left at Orion".

The moon is the best for target practice :-)

On the computer, Stellarium is a great free program to see what's up. Check where the planets are.

On your phone, there are plenty of free planetarium apps (e.g. Android Sky Map)

Use the finder and put the 25mm eyepiece in to find them. Swap to the 10mm to see the planets in detail. 65x is just enough to recognize Saturn's rings and possibly see faint cloud bands on Jupiter. A long eye-relief 4mm 58° HR Planetary clone eyepiece is a good addition in the near future, but don't get eyepiece kits or short Plössl (poor eye-relief, unusable).

Check for objects such as the Ring nebula/M57, double star Albireo, Cluster M13, Galaxy pair M81/M82 if you are at a relatively dark location.

Binoculars can help when starting out to find things.

Clear skies! Have fun! :-)

Hi :-)

Nice little bucket!

For planets: Consider the 4mm 58° HR Planetary (clones), but not the cheap 4mm 62° or a short 4mm 52° Plössl.

http://blog.pixelgiraffe.com/wp-content/uploads/2016/03/130-650-high_3.png

http://blog.pixelgiraffe.com/wp-content/uploads/2015/11/awb_Heritage_Magnifications_small.png

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https://aliexpress.com/item/32724445552.html (Random link, ymmv, check recent seller/item reviews)

https://www.amazon.com/Oumij1-Monocular-Planetary-Astronomical-Telescope/dp/B08CY2ZZ8K/

(Or for a bit more, the Dual-ED 60° and similar)

A cheap barlow and the kit eyepiece can work, but it's not really great. It introduces chromatic aberation, adding to the already not-so-great 10mm Super/RK eyepiece.

A shorter eyepiece as the 4mm will make things dim; I've the 3.2mm HR Planetary and the 2.5mm, especially the 2.5mm is nearly unusable.

Clear skies :-)

Hi :-)

I'd recommend a decent 4mm eyepiece instead of a barlow.

But not the cheap 4mm 62° or a short 4mm 52° Plössl (poor eye-relief).

Field of view simulation

Magnification

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[4mm Aliexpress/China](https://aliexpress.com/item/32724445552.html (Random link, ymmv, check recent seller/item reviews)

Random one on Amazon (Agenaastro has them too)

(Or for a bit more, the Dual-ED 60° and similar)

A cheap barlow and the kit eyepiece can work, but it's not really great. It introduces chromatic aberration, adding to the already not-so-great 10mm Super/RK eyepiece.

A shorter eyepiece as the 4mm will make things dim; I've the 3.2mm HR Planetary and the 2.5mm, especially the 2.5mm is nearly unusable.

Clear skies :-)

Hello :-)

Awesome!

• Turn left at Orion: A great guide, unless he already knows his way around the night sky and has books.

• Collimation cap: Nice to have. A more sophisticated, short cheshire-sight-tube doesn't break the bank either. There's also the "no-tools" method so it's possible to survive with no additional tools :-)

• Planetary eyepiece: More or less mandatory as the kit eyepieces don't quite cut it.

  • Field simulation: http://blog.pixelgiraffe.com/wp-content/uploads/2020/06/fov-150-750.png
  • https://aliexpress.com/item/32724445552.html (Random link, ymmv, check recent seller/item reviews)
  • https://www.amazon.com/Oumij1-Monocular-Planetary-Astronomical-Telescope/dp/B08CY2ZZ8K/
  • https://agenaastro.com/bst-1-25-uwa-planetary-eyepiece-4mm.html
  • Avoid the short cheap 4mm 62° or short 4mm Plössl/52° due to poor eye-relief.

• Shroud: Only really required if it's not dark at the observing location (e.g. street lights will ruin the contrast even when observing planets) or if dew is getting an issue. For the 130p I used 50 cents worth of cardboard as temporary fix but it held up so well that I kept it. Others use velcro, black plastic foam sheets or such. More weather proof for sure.

• "Table": For the 130p I use an Ikea Bekväm or Kyrre, or a crate. Folding camping tables are usually too weak for using a telescope. Not sure what would be a nice travel-table for the larger 150p, but a box/crate can double as transportation container for all the stuff :-) And a small folding chair perhaps.

Clear skies!