Question about premium eyepieces

[OzStarGazer]

Hi, I have a BST Starguider ED 8mm eyepiece and I like it but I cannot attach a camera adapter bracket to it because it is too big, at least for my camera adapter bracket. (The camera adapter bracket works fine with the default eyepieces that came with my two scopes though.)
So I was wondering if there are any "thin" premium eyepieces? They all look bigger than standard eyepieces, but I don't know all brands.
Thanks!

[Astro_Bot]

Baader Hyperion eyepieces have screw threads under the rubber eyecup and ring that can be used for attaching a camera.

Also, GSO make camera projection eyepieces.

Whether either if these is "premium" is a matter of conjecture.

[barx1963 (Malcolm)]

I am assuming you are talking about an afocal adapter similar to this?http://www.bintel.com.au/Astrophotog...oductview.aspx

I had one at one stage and yes it would only work on plossl eyepieces or similar size. In the televue range most of the type 6 EPs, and certainly the 13mm which is the pick of them are of this size. But exxy though!!

Malcolm

[brian nordstrom (As avatar)]

Give the Telvue's plossls a look at , premium eyepieces at a reasonable price , I have the 15mm and 32mm and they easily compare in viewing to my much more expensive Radians , Panoptics and Naglers in all areas but field of view, you don't need that for what you are doing .
Brian.

[OzStarGazer]

Thanks for the replies. I will have a look at the Tele Vue eyepieces. Yes, Malcolm, that's what I meant. It can be useful because prime focus is good, but the magnification is not so high, so using a camera adapter with a compact camera can also be an option, particularly at high magnifications.

[astro744]

Originally Posted by OzStarGazer

Thanks for the replies. I will have a look at the Tele Vue eyepieces. Yes, Malcolm, that's what I meant. It can be useful because prime focus is good, but the magnification is not so high, so using a camera adapter with a compact camera can also be an option, particularly at high magnifications.

You mention prime focus; how are you doing this? What camera do you have?

If you are using a DSLR then an alternative and preferred method to afocal is eyepiece projection and for that you need a different adapter. See http://www.bintel.com.au/Astrophotog...oductview.aspx

For eyepiece projection you mount the eyepiece (slim 8mm Tele Vue Plossl is ideal) inside the adapter. One end goes into the focuser and the other end connects to the T-ring which is connected to the DSLR camera (without lens).

The afocal method may not work all that well if at all with an 8mm Plossl due to insufficient eye relief.

See http://www.televue.com/engine/TV3b_p...5#.U8b7CJSSy5I for a discussion on different imaging methods.

Note an alternative to eyepiece projection is by using a Powermate and no eyepiece. This is probably the most common method now. A Barlow can be used in lieu of a Powermate but the latter are available in 2.5x, 4x & 5x with the 5x model capable of over 7x depending on focal plane distance.

A DSLR with lens would be too heavy for the afocal adapter originally referred to. These adapters suit small compact digital cameras and work well with 32 to 40mm Plossl eyepieces with good eye relief, (they will work with any eyepiece with a good 20mm of eye relief). To increase the image scale you use the compact camera zoom feature.

When using eyepiece projection method the magnification factor is determined by the distance from eyepiece to focal plane and the eyepiece used. Meade make a variable eyepiece projection adapter with sliding section to vary the eyepiece camera distance. See http://www.meade.com/products/access...pter-1-25.html

Most eyepiece projection adapters require slim eyepieces and Plossls or Orthos work very well.

[OzStarGazer]

Good idea, thanks. I have seen great results even with small telescopes with eyepiece projection (sometimes really astonishing), so I could indeed give it a go too. I do have a small compact camera too if the DSLR is too heavy for eyepiece projection.
PS: Yes, I wanted to use a DSLR camera for prime focus. I have a Nikon D5100. Unfortunately there was not much too see at night since I bought my refractor, but I tried during the day and it worked fine. It also worked fine with a Barlow.
When you mention the Powermate method, do you mean just the Powermate or the Barlow and then afocal method?
By the way, does it have to do with eye relief? I do like my 8mm premium eyepiece (for viewing), but taking photos in afocal mode is not easy. I have to zoom in, move around... It is so much easier with simple eyepieces!

[astro744]

Originally Posted by OzStarGazer

Good idea, thanks. I have seen great results even with small telescopes with eyepiece projection (sometimes really astonishing), so I could indeed give it a go too. I do have a small compact camera too if the DSLR is too heavy for eyepiece projection.
PS: Yes, I wanted to use a DSLR camera for prime focus. I have a Nikon D5100. Unfortunately there was not much too see at night since I bought my refractor, but I tried during the day and it worked fine. It also worked fine with a Barlow.
When you mention the Powermate method, do you mean just the Powermate or the Barlow and then afocal method?
By the way, does it have to do with eye relief? I do like my 8mm premium eyepiece (for viewing), but taking photos in afocal mode is not easy. I have to zoom in, move around... It is so much easier with simple eyepieces!

The Tele Vue link http://www.televue.com/engine/TV3b_p...5#.U8c2rJSSy5J explains it reasonably well although there are probably many other links online.

Prime focus method is camera + T-ring + T-adaptor (1.25" or 2') into focuser of telescope. the telescope itself is the 'prime lens'. Must be done with DSLR or other interchangeable lens camera.

Eyepiece projection method is Camera + T-ring + eyepiece projection adapter inserted into focuser. The eyepiece is inside the adapter, (typically 1.25" only). The eyepiece projects a magnified image onto the film (CCD) plane. Must be done with DSLR or other interchangeable lens camera.

Afocal method is camera with lens, either DSLR or compact positioned in front of eyepiece which has been inserted into telescope as would be for visual observing. Either hand hold the camera in front of the eyepiece or use a special bracket to hold the camera. This method is best for lightweight compact cameras. Eyepieces with good eye relief are needed or vignetting will result.

Powermate or Barlow method is with camera + T-Ring + T adaptor (1.25" or 2") into Powermate or Barlow which has been inserted into focuser. No eyepiece is used. Powermates also have optional T-threaded upper section that replaces the standard visual upper section of the Powermate. Again no eyepiece is used.

Note extending the focal length also extends the focal ratio significantly. In the days of film eyepiece projection was used for photographing planets and close-ups of the Moon. I remember using f72 often and typical exposures of bright planets was 0.5 to 2 sec, sometimes longer depending on film and object. Good tracking and polar alignment was critical and you can forget about guiding as the target must simply not move. Also shake due to mirror flip in the SLR had to be eliminated. I would use a box (without lid) painted black inside and place it over the front of the telescope. I would then start the exposure and slowly move the box away from the telescope but still covering the target until I was sure there were no more vibrations. I would then expose the target and manually count seconds (or half seconds) and then end the exposure by placing the box back and then releasing the shutter cable, (must all be done in Bulb setting on camera). (You could also use some black velvet in lieu of a box).

The eyepiece projection method was never used for deep sky photography since the exposure times were too long. If you wanted better image scale you needed a longer telescope. If you also got a large optic you then also got a faster telescope helping reduce exposure times.

Nowadays planetary and Luna imaging is done with webcam style sensors capturing many frames per second and then stacking them with suitable software giving far more impressive results than a single snapshot hopefully during excellent seeing would ever give.

[OzStarGazer]

Thanks.
Oh today I also got my Celestron microscope imager. It works fine with the microscope and although I haven't tested it with the telescope yet it should be fine. I have only tested the adapter and it is OK, so at least it fits in.
The article you linked too looks pretty good and clear. It's bookmarked now!
I have taken many photos in afocal mode and a couple in prime focus (daytime) so far. But I really like to explore different methods.
We will see how the webcam works tomorrow, even if it will probably be daytime.
Eyepiece projection as done in the old days sounds interesting too. I wonder if anybody is still using film and eyepiece projection these days? At least occasionally?

[astro744]

Originally Posted by OzStarGazer

Thanks.
Eyepiece projection as done in the old days sounds interesting too. I wonder if anybody is still using film and eyepiece projection these days? At least occasionally?

I may just have to try it as I found an unused roll of Fuji 400 in the fridge.

Note you can still use eyepiece projection with a DSLR in lieu of an SLR. The advantage of digital is of course instant results.

With film you had to wait for the film to come back before you saw your results and found out whether exposure and focus were good and seeing was steady enough. Also with eyepiece projection you need to photograph in steady seeing and you cannot really see what the target is doing so it's more of a hit or miss procedure.

The moon is a good target for eyepiece projection as it is bright and exposures are shorter. However, I would still use the manual curtain/box in front of the telescope for exposures as little as 1/8 sec or best guesstimate for very long focal ratios and/or slower film. Tech Pan 2415 was the best B/W fine grain film but low ASA/ISO.

[OzStarGazer]

That would be interesting. Maybe you can take some pics of the process if you go for it.
Yes, the advantage of digital is instant results as well as money, as it is cheap to just take digital pics and only keep the ones you like.That's why on many astrophotography websites they say take as many digital pics as you can. Sometimes the conditions change in a few minutes so at least a few pics will be fine.
Another advantage is space of course. I have got stuff everywhere in my apartment and adding stacks of photos would be cumbersome..

[OzStarGazer]

OK, I couldn't resist and I just tried the microscope webcam. It seems to work fine with the telescope too. I could see the leaves very clearly, but they were moving a lot!

[OzStarGazer]

A pity there doesn't seem to be a 6mm TeleVue Ploessl... I wonder why they don't make it?
So either another 6mm Ploessl (another good brand) or maybe a "fat" eyepiece and hand-held camera after all...
PS: I assume this is really bad? http://www.ebay.com.au/itm/121351703255?ssPageName=STRK:MEWAX: IT&_trksid=p3984.m1423.l2649
The description is a joke...

[OzStarGazer]

Originally Posted by OzStarGazer

OK, I couldn't resist and I just tried the microscope webcam. It seems to work fine with the telescope too. I could see the leaves very clearly, but they were moving a lot!

OK, last night I woke up at about a quarter to 4 and there was a beautiful moon in front of my balcony.
So I quickly grabbed the computer, the microscope webcam and tried to take some pics. Of course (my usual luck!) after the second picture the moon almost completely disappeared behind a thick haze....
Anyway, I have noticed that
1) Unfortunately the whole moon didn't fit it (not even with a focal reducer, which I quickly tried), but I expected that;
2) In the first two pics before the haze a part of the moon is overexposed. I usually manage to avoid this when taking pics in afocal mode by moving the camera a bit, but this was not possible with the webcam, and reducing the exposure would have made the visible craters dull...
3) After that as I said the moon almost completely disappeared behind a thick haze and although I still managed to take a couple of pics they are pretty dark and more out of focus than the first two pics.
All in all I think relatively good results can be achieved with this webcam if the weather is favourable.
Recording a video would have probably been better, but I could not because of the haze. So next time...

[OzStarGazer]

Well, I decided to give the TMB a go anyway because it is pretty cheap on AliExpress. I will probably accumuate many eyepieces anyway over the years...

[Don Pensack]

Originally Posted by OzStarGazer

Hi, I have a BST Starguider ED 8mm eyepiece and I like it but I cannot attach a camera adapter bracket to it because it is too big, at least for my camera adapter bracket. (The camera adapter bracket works fine with the default eyepieces that came with my two scopes though.)
So I was wondering if there are any "thin" premium eyepieces? They all look bigger than standard eyepieces, but I don't know all brands.
Thanks!

The easiest solution is an afocal camera adapter that has a larger opening or clearance, and they exist from several manufacturers. The one you have just has a small opening and isn't designed for a lot of modern eyepieces.

[Camelopardalis (Dunk)]

Originally Posted by OzStarGazer

Well, I decided to give the TMB a go anyway because it is pretty cheap on AliExpress. I will probably accumuate many eyepieces anyway over the years...

Most of us do