My 130p Heritage came with the stock 25mm and 10mm plossls. I thought I'd get a 6mm to go with it and it arrived today from Australian Geographic. This would give me magnifications of 26x 65x and 108x.
The first thing I noticed was how heavy it was compared to the stock ones, which seemed to be a good sign to me. When put side by side it is also longer than the 10mm.
It's raining today so I tried it out quickly on the balcony with stuff in neighbours gardens like gates, chairs, kids toys and TV antennae. You can easily tell the difference between the 25 and 10 (39x) but with the 10 and 6mm (difference of 108-65= 44) I can't really see much, if any difference, apart from a whole heap better image and contrast. Am I missing something, is it an optical illusion or did I spend too much time in Irish Murphy's before coming home.
So as I don't know anything about optics is there a way to tell the focal of each EP?
* is there any markings on the new eyepiece (EP), such as focal length in mm, and design such as 'plossl' 'super plossl' 'pl' or other?
* is it a plossl that you got?
* do you have any pictures to show us?
If it's a plossl you got, a 6mm would be smaller than the 10mm. Its eye lens (the lens you look into) would also be smaller.
if you have a design other than plossl, size could be different, but no guarantee of superior quality. But if it is a 6mm, there should be a noticeable change in magnification size.
The difference in magnification between a 25mm eyepiece and a 10mm eyepiece is equal to 25/10 = 2.5x. The image in the 10mm will be 2.5x bigger than the image in the 25mm.
The difference between 10mm and 6mm = 10/6 = 1.67x. The image in the 6mm will be 1.67x bigger than in the 10mm.
The difference between 25mm and 6mm = 25/6 = 4.17x. The image in the 6mm will be 4.17x bigger than in the 25mm.
If the apparent field of the eyepieces is the same the the object will have less surround around it as you go higher in magnification. If the eyepiece apparent field is different then you could have a situation whereby the same amount of surround is visible with the 6mm as with the 10mm even though the overall size of everything is bigger. This could occur if for example say the the 10mm had a 50 deg apparent field and the 6mm had an 82 deg apparent field.
Now given your 6mm is about the same size as your 10mm I would say you have a Plossl and the apparent fields are the same. The extra weight is probably the better glass in the 6mm also giving you a better image.
If you look more closely you should see the image through the 6mm to be just over one and a half times (1.67x) bigger than the 10mm.
im curious which ep you got from Aus geographic -also how happy r u in general with the heritage 130p?
in response to your question as others have suggested -if it is much heavier it most likely has more glass elements & is a wider field of view deign -show it magnifies more but you see a wider view than the typical ep that came with your scope
Aim at bricks on a wall far away with each of the 6mm and 10mm eyepieces.
Count the number of bricks that you can see from edge to edge in each field. Unless you've bought a good wide angle 6mm eyepiece, you should be seeing more bricks with the 10mm.
Cheers,
Regards,
Renato
Alex, here's my 3 eyepieces, 25, 10 and 6mm from left to right, the 6mm being the new EP. It has a smaller eye lens than the 10. They are all marked super, and the new one super plossl 6mm. I'm sure I've read the stock ones plossl.
It's raining so I'm not going out just yet to try brick counting.
Daniel I bought a 6mm plossl from AG shop. As for the Heritage I love it and will keep it when I eventually upgrade. So quick and easy to just pick up and take outside. But you must remember this is my first scope.
Astro, if the difference between the 10 and 6mm is only 1.67x maybe it's just me and I can't see it with the stuff I've been looking at, but I do find it hard to see any appreciable difference.
You are wrong here , its a myth that say at 100x the image is 100x bigger , its actually bought 100x closer , so if you are viewing something say 10km away it would look only 1km seen naked eye at 1x away thru an eyepiece/telescope combo giving you 100x .
Jupiter at about 440 million km's away would look like it was 100x closer at 44 million km's away seen with the naked eye thru this combo .
Hope this helps .
Brian.
Quote:
Originally Posted by astro744
Just to clarify:
The difference in magnification between a 25mm eyepiece and a 10mm eyepiece is equal to 25/10 = 2.5x. The image in the 10mm will be 2.5x bigger than the image in the 25mm.
The difference between 10mm and 6mm = 10/6 = 1.67x. The image in the 6mm will be 1.67x bigger than in the 10mm.
The difference between 25mm and 6mm = 25/6 = 4.17x. The image in the 6mm will be 4.17x bigger than in the 25mm.
If the apparent field of the eyepieces is the same the the object will have less surround around it as you go higher in magnification. If the eyepiece apparent field is different then you could have a situation whereby the same amount of surround is visible with the 6mm as with the 10mm even though the overall size of everything is bigger. This could occur if for example say the the 10mm had a 50 deg apparent field and the 6mm had an 82 deg apparent field.
Now given your 6mm is about the same size as your 10mm I would say you have a Plossl and the apparent fields are the same. The extra weight is probably the better glass in the 6mm also giving you a better image.
If you look more closely you should see the image through the 6mm to be just over one and a half times (1.67x) bigger than the 10mm.
I can't make head nor tail of your post Brian. Regardless of who's right or wrong, your figures are wrong. Jupiter at 440 million, brought 100x
closer as you say, would be 4.4 million kms, not 44, and at that distance
[only 11 x the distance to the moon] it would look enormous [100x
normal, or 3.72x the size of the moon.] An object 10kms away brought 100x closer would look to be 100 metres away, not 1km. [100x closer].
raymo
yep my maths is wrong but the 100x closer is right .
thanks for the correction , I had just walked in after a 12 hour day ,,, ..
Brian.
Quote:
Originally Posted by raymo
I can't make head nor tail of your post Brian. Regardless of who's right or wrong, your figures are wrong. Jupiter at 440 million, brought 100x
closer as you say, would be 4.4 million kms, not 44, and at that distance
[only 11 x the distance to the moon] it would look enormous [100x
normal, or 3.72x the size of the moon.] An object 10kms away brought 100x closer would look to be 100 metres away, not 1km. [100x closer].
raymo
You are wrong here , its a myth that say at 100x the image is 100x bigger , its actually bought 100x closer , so if you are viewing something say 10km away it would look only 1km seen naked eye at 1x away thru an eyepiece/telescope combo giving you 100x .
Jupiter at about 440 million km's away would look like it was 100x closer at 44 million km's away seen with the naked eye thru this combo .
Hope this helps .
Brian.
The same way I cannot make an object bigger is the same way you cannot make an object closer. They only appear that way. Bigger or closer it doesn't matter, the ratio and is the same.
e.g. The Moon is 400x closer to us than the Sun and is also 400x smaller and that is why we have eclipses since the angular diameters are the same.
Alex, here's my 3 eyepieces, 25, 10 and 6mm from left to right, the 6mm being the new EP. It has a smaller eye lens than the 10. They are all marked super, and the new one super plossl 6mm. I'm sure I've read the stock ones plossl.
It's raining so I'm not going out just yet to try brick counting.
Daniel I bought a 6mm plossl from AG shop. As for the Heritage I love it and will keep it when I eventually upgrade. So quick and easy to just pick up and take outside. But you must remember this is my first scope.
My son has the same 25 & 10 that came with his ST80. They are very light and I wouldn't be surprised if the lenses are plastic. The 6mm looks like a Meade Series 4000 Super Plossl, a quality eyepiece. However it was available in 6.4mm NOT 6mm.
If you have a 6.4mm eyepiece then your image will appear 10/6.4 = 1.56x bigger and this still should be noticeable. The apparent field of the 4000 series is 52 degrees, a touch wider than the standard Plossl.
Nearly everything I've read about the Heritage 130p says the eyepieces are good for stock ones. I've very limited experience but they seem OK to me, but the new eyepiece is much better.
And it's still raining
Edit: It's stopped raining but I'm off out to dinner now, I'll have to have a look tomorrow now.
The stock "super"eyepieces that came with ur scope are Kellners and not plossls, modified achromats as they prefer to call them[LINK]. while they make for some good beginner eyepieces, these particular ones suffer from what is known as ghosting of bright objects and internal scatter which will give a "milky" appearance to the field. Good thing is, as long as one does not view through better eyepieces, you probably wont hve a problem using those, as the will still deliver good images.
The 6mm eyepieces u hve bought is indeed an plossl and they rank among the sharpest eyepieces available. The onene negative side is they lack comfortable eyerelief at smaller focal lengths.
Hi cosmosat, looks like you are indeed right. I was watching a YouTube vid earlier and the bloke said the EPs he was looking at that came with some scopes were MAs and they looked suspiciously like mine. Also since looking through the new eyepiece I can now see that the old ones look a bit light on colour, probably what you meant by milky.
This doesn't change the fact that there's no difference in the power though. I photo'd a big switch on a power pole about 800m yesterday arvo and then measured it by hand and they were exactly the same. So I tried it again a couple of times and got the same result.
So if they are the same power are they 10mm or 6mm? I'd go along with the 6mm being more accurate, I suppose I'll have to buy more EPs to find out!
You are wrong here , its a myth that say at 100x the image is 100x bigger , its actually bought 100x closer , so if you are viewing something say 10km away it would look only 1km seen naked eye at 1x away thru an eyepiece/telescope combo giving you 100x .
yep my maths is wrong but the 100x closer is right .
..
