Eyepiece projection issues

[Mark2022]

I bought an Altair 1.25" LER 5mm planetary eyepiece for the purposes of using it for eyepiece projection photography coupled with a 2x barlow  attached to my Meade 8 inch SCT.  The problem: My 1.25" eyepiece  projection extension isn't 'fat' enough (internal diameter) to fit the eyepiece into it. Not only that but it is not long enough either to then allow the t adaptor to fit onto the eyepiece projection 'unit' and connect to my DSLR. Feel like I've just wasted money on the eyepiece unless someone has a solution? Even if that solution involves buying another eyepiece projection barrel (I thought maybe, a 2 inch version but then the nosepiece of the 1.25" eyepiece wouldn't sit in such). Is there a simple 'fix' for this and I'm just being slow? It wouldn't be the first time! 

Just to add - Even my Meade 40mm series 4000 is too long for the eyepiece projection adaptor.

Edited July 14, 2023 by Mark2022
Just an added piece of info.

[Louis D]

Thos eyepiece projection adapters haven't changed in 40 years.  They were intended to be used with the Kellners and Orthos of the day.

That being said, why would you want to push your SCT with the equivalent of using a 2.5mm eyepiece?  It already has a ~2000mm focal length natively.  Going to projection with a 2.5mm eyepiece is going to massively increase the image scale.  The f-ratio is going to drop from f/10 to f/400.  That's insanely slow with a 0.25mm exit pupil.

Why not just try using the DSLR natively on the scope with a 1.25" or 2" (depending on your visual back size) to T-thread adapter?  Guiding a 2000mm focal length scope is difficult enough.  From there, you could progress to high powers with the Barlow alone if you think you still need more magnification.

Maybe I'm misunderstanding your use case.  What do you plan to image/photograph?

[Mark2022]

22 minutes ago, Louis D said:

Thos eyepiece projection adapters haven't changed in 40 years.  They were intended to be used with the Kellners and Orthos of the day.

That being said, why would you want to push your SCT with the equivalent of using a 2.5mm eyepiece?  It already has a ~2000mm focal length natively.  Going to projection with a 2.5mm eyepiece is going to massively increase the image scale.  The f-ratio is going to drop from f/10 to f/400.  That's insanely slow with a 0.25mm exit pupil.

Why not just try using the DSLR natively on the scope with a 1.25" or 2" (depending on your visual back size) to T-thread adapter?  Guiding a 2000mm focal length scope is difficult enough.  From there, you could progress to high powers with the Barlow alone if you think you still need more magnification.

Maybe I'm misunderstanding your use case.  What do you plan to image/photograph?

Jupiter. At prime focus, Jupiter is tiny. I won't be guiding, I'll just  let the LX10 motor run to keep Jupiter in the FOV and take a video for subsequent stacking. I did it last  year using a 10 or 15mm eyepiece but it still was very small. I got the 5mm (perhaps the barlow might not be needed) because I wanted brighter than what my meade 4mm plossl offers. I could use the 4mm plossl  in the EPP adaptor but  it's then quite dim.

[Elp]

Jupiter is tiny because your dslr sensor is so big. You can crop the image but I feel you won't get the detail due to the tiny size being projected onto the camera sensor so detail will be lost (hence your attempt to magnify). As per above, by lowering the focal ratio it will also be very dim, maybe to the point you can't even see it in images. I'd try it native first with a 2x barlow only, this is how I did it last with my C6 so 3000mm focal length. I was however using a planetary camera which has a tiny sensor in comparison but Jupiter was a decent size as a result without having to crop or make a region of interest (ROI) crop. Planetary cameras also have high frame rates, much higher than video 24/25/30/60 frames per second which is beneficial when trying to freeze the atmospheric seeing.

You could try an eyepiece which has a t ring male thread to which you can screw your dslr directly to it, I've never done it myself due to what I've mentioned but the Celestron 8-24 zoom eyepiece is built for it.

[Mark2022]

Anyone have an idea how I can use a 5mm LER  planetary eyepiece with eyepiece projection? That's the answer I'm looking for, if such exists.

Just FYI.... 9.7mm eyepiece, eyepiece projection, DSLR APS-C camera. Perfectly capable of taking decent enough video of Jupiter at a reasonable size. I'd just like to use the 5mm I've just bought.

 

 

Edited July 14, 2023 by Mark2022
Forgot to add video.

[Louis D]

13 minutes ago, Mark2022 said:

Anyone have an idea how I can use a 5mm LER  planetary eyepiece with eyepiece projection? That's the answer I'm looking for, if such exists.

Look for a Scopetronix Maxview DSLR.  It can easily accommodate your 5mm eyepiece.  That ebay offer might be the only new old stock one in the world.

[Mark2022]

Thanks Louis. That's just the product I would need but, I'm afraid, way out of my budget. I have no idea why manufacturers can't just make one with a wider/longer barrel of the type we are accustomed to.

[michael.h.f.wilkinson]

The thing is, you are spreading out the photons over far too many pixels. For optimal results, you need to match the focal ratio to the pixel size. I remember using 3 s exposures at 1600 ISO and 19 m (that's right: 19,000 mm) focal length with my C8 using EP projection with the SLR I had, as planetary cameras and even webcams were a thing of the future at the time. You get far better results using either crop-mode video (uncompressed, 1:1 relation between physical pixels and actual pixels in the image, unlike the regular video modes) or a proper planetary camera. I typically use tele-centric Barlows, which give better results than EP projection. For my ASI183MC camera I either use native F/10, or perhaps F/13 with a 1.3x Siebert optics tele-centric Barlow. With the older cameras with larger pixels I went for either a Meade 2x TeleXtender or a 2.5x Tele-Vue PowerMate.

You can get great results even with cheap planetary cameras. The result below was with an ASI224MC, which pop up second-hand for modest prices. The ASI120MC-S is also quite a performer for a low price

[Louis D]

13 hours ago, Mark2022 said:

Thanks Louis. That's just the product I would need but, I'm afraid, way out of my budget. I have no idea why manufacturers can't just make one with a wider/longer barrel of the type we are accustomed to.

Because they would cost as much as the MaxView adapter, and no one would buy them.  That is what happened to the MaxView, and now they are no longer made.  Instead, they sell small, cheap adapters that don't work with modern eyepieces to hit a certain price point.

[johnturley]

On 14/07/2023 at 17:47, Louis D said:

Thos eyepiece projection adapters haven't changed in 40 years.  They were intended to be used with the Kellners and Orthos of the day.

That being said, why would you want to push your SCT with the equivalent of using a 2.5mm eyepiece?  It already has a ~2000mm focal length natively.  Going to projection with a 2.5mm eyepiece is going to massively increase the image scale.  The f-ratio is going to drop from f/10 to f/400.  That's insanely slow with a 0.25mm exit pupil.

Why not just try using the DSLR natively on the scope with a 1.25" or 2" (depending on your visual back size) to T-thread adapter?  Guiding a 2000mm focal length scope is difficult enough.  From there, you could progress to high powers with the Barlow alone if you think you still need more magnification.

Maybe I'm misunderstanding your use case.  What do you plan to image/photograph?

As Mark has stated, using the DSLR natively will result in an image scale far too small on planets, and a 2x Barlow alone won't give sufficient amplification. Having said that a 2.5 mm eyepiece with ~2000mm focal length almost certainly gives too much amplification, and make it difficult to focus.   I found that with my 14in Newtonian (~1800mm focal length), and Canon 6D full frame digital SLR, I got a reasonable image size on Jupiter with a 9.7mm plossl. With a cropped APS-C sized senor sensor, a 12-15mm eyepiece will probably be about right. I kept the 15, 12.5, and 9.7 mm eyepieces from my original set of smoothside Meade Series 4000 plossls specifically for eyepiece projection, a lot of modern eyepieces will be too fat to fit in most eyepiece projection tubes.

Having said all that, you will get much better results with a dedicated planetary camera such as the ZWO 224MC which is not too expensive at around £200, as these have a much faster frame rate, allow more cropping than most digital SLR's, and the associated software (I use Sharpcap, followed by AutoStakkert and Registax) makes processing easier.

For comparison I attach 2 images of Mars taken through my 14in Newtonian showing roughly the same surface features, the first was taken October 2020 using eyepiece projection with a 9.7mm plossl with my Canon 6D, the second using a ZWO ASI 462 Planetary Camera with a 2.5x Powermate taken in December 2022 clearly shows much more detail, despite if I recall correctly, more detail was visible visually in October 2020 when Mars was much closer.   

 

Edited July 29, 2023 by johnturley

[Mark2022]

4 hours ago, Louis D said:

Because they would cost as much as the MaxView adapter, and no one would buy them.  That is what happened to the MaxView, and now they are no longer made.  Instead, they sell small, cheap adapters that don't work with modern eyepieces to hit a certain price point.

Louis, I don't "buy it" that, to add half an inch to the inside diameter of the existing designs need to add a factor of 10 to their cost.  You can pick up these eyepiece projection adaptors for a tenner or a bit more.  There is absolutely no need for a significant increase in cost because of making the barrel diameter 10 mm or so greater. I keep finding, with this hobby, that I wish I had some turning machines and a little workshop.  The rip offs are ridiculous.

[Mark2022]

Just having a laugh guys but do any of you think in terms of not having a bottomless pit of money? I guess none of you are retired and live on a fixed, minimal income? Once  you've spent a few K and find you keep needing to buy more and more, while people say "You can get a good ZWO for £200" or a Projection  adaptor for £100+, as if there's no end to the spend, I have to laugh. I hope you all retire millionaires. LOL

[windjammer]

How about if you packed out the protruding barrel of the eyepiece with layered tubes of plastic pipe (slit the pipe so it can be compressed or expanded to fit over inner /outer layers) until it fits into a 2 inch eyepiece compression adapter.  If the 2" adapter has an M42 or m48 thread at the eyeball end you should be able to finagle your projection hardware onto it.  If the eyepiece barrel is long enough you might get a hose clamp around the pipe to eyepiece barrel as well as the 2" adapter for extra grunt.  Take your point completely about having a lathe for this hobby!

Simon

[Elp]

Have you tried something like this (yes there are much cheaper ones out there if you look):

https://www.amazon.co.uk/Neewer-Telescope-Compatible-Projection-Astrophotography/dp/B0BPM94KB9/ref=mp_s_a_1_11?crid=2Y7E5DZZWLITD&keywords=1.25+extension+tube&qid=1689446617&sprefix=1.25+extension%2Caps%2C879&sr=8-11

It's not exactly what you're looking for but can try with a Barlow, it's likely you've already tried similar though by connecting a 1.25 adaptor to the t ring connected to your camera (ie without this sort of extender).

Edited July 15, 2023 by Elp

[Elp]

Isn't this what you're after (read the description):

https://www.firstlightoptics.com/adapters/tele-camera-adaptor-for-eyepiece-projection-astrophotography.html

I know baader also do some things like this as a lot of their eyepieces are t ring threaded, they do a lot of adaptors to suit.

Edited July 15, 2023 by Elp

[Mark2022]

That's actually a reasonable idea Windjammer. I was thinking along the lines of a 2 inch but didn't really give it further detailed thought. I like it! 

[Mark2022]

41 minutes ago, Elp said:

Isn't this what you're after (read the description):

https://www.firstlightoptics.com/adapters/tele-camera-adaptor-for-eyepiece-projection-astrophotography.html

I know baader also do some things like this as a lot of their eyepieces are t ring threaded, they do a lot of adaptors to suit.

I wasn't following you Elp until I realised that I think you've missed my fundamental point (I think), which is, yes there are adaptors out there for projection but they are neither long nor wide enough to fit the larger sized 1.25 inch eyepiece barrels we get  today such as the Altair LER 5mm which I just bought.

Am I reading this thread right?  Do we have Rush and  ELP fans among the astro community? Not that it would surprise me since I think we would tend to have a far more discerning taste for music.  Watching the youtube channels drives me nuts with some of the non copyright 'music' they use. 🙂

[Mark2022]

5 hours ago, johnturley said:

As Mark has stated, using the DSLR natively will result in an image scale far too small on planets, and a 2x Barlow alone won't give sufficient amplification. Having said that a 2.5 mm eyepiece with ~2000mm focal length almost certainly gives too much amplification, and make it difficult to focus.   I found that with my 14in Newtonian (~1800mm focal length), and Canon 6D full frame digital SLR, I got a reasonable image size on Jupiter with a 9.7mm plossl. With a cropped APS-C sized senor sensor, a 15-12mm eyepiece will probably be about right. I kept the 15, 12.5, and 9.7 mm eyepieces from my original set of smoothside Meade Series 4000 plossls specifically for eyepiece projection, a lot of modern eyepieces will be too fat to fit in most eyepiece projection tubes.

Having said all that, you will get much better results with a dedication planetary camera such as the ZWO 224MC which is not too expensive at around £200, as these have a much faster frame rate, allow more cropping than most digital SLR's, and the associated software (I use Sharpcap, followed by AutoStakkert and Registax) makes processing easier.

For comparison I attach 2 images of Mars taken through my 14in Newtonian showing roughly the same surface features, the first was taken October 2020 using eyepiece projection with a 9.7mm plossl with my Canon 6D, the second using a ZWO ASI 462 Planetary Camera with a 2.5x Powermate taken in December 2022 clearly shows much more detail, despite if I recall correctly, more detail was visible visually in October 2020 when Mars was much closer.   

 

Nice shots John.

[Mark2022]

11 hours ago, michael.h.f.wilkinson said:

The thing is, you are spreading out the photons over far too many pixels. For optimal results, you need to match the focal ratio to the pixel size. I remember using 3 s exposures at 1600 ISO and 19 m (that's right: 19,000 mm) focal length with my C8 using EP projection with the SLR I had, as planetary cameras and even webcams were a thing of the future at the time. You get far better results using either crop-mode video (uncompressed, 1:1 relation between physical pixels and actual pixels in the image, unlike the regular video modes) or a proper planetary camera. I typically use tele-centric Barlows, which give better results than EP projection. For my ASI183MC camera I either use native F/10, or perhaps F/13 with a 1.3x Siebert optics tele-centric Barlow. With the older cameras with larger pixels I went for either a Meade 2x TeleXtender or a 2.5x Tele-Vue PowerMate.

You can get great results even with cheap planetary cameras. The result below was with an ASI224MC, which pop up second-hand for modest prices. The ASI120MC-S is also quite a performer for a low price

That's a beauty, Michael!

[Elp]

What's the OD?

[Mark2022]

8 minutes ago, Elp said:

What's the OD?

My Meade  26mm series 4000 plossl (at 42mm OD) will just fit the eyepiece proj adaptor I have. However, the Altair LER 5mm is a 44mm OD. My point to Louis is it should not take a jump  from say £20 to over  £100 just to increase the capability of an adaptor to take a wider barrel lens (or longer barrel). We're just talking drilling a wider hole in a similar piece of metal. However, what we have is manufacturers simply setting up their production lines to churn out the same adaptor sizes for years and then saying "Well, if you want us to change our jigs to churn out anything different, we're going to charge you 4 or 5 or 10x more".

[Mark2022]

Think of this with, instead of an eyepiece clamp, a M48 thread at one end and either an M48 or M42 thread (or 1.25" nosepiece) at the telescope end. Perhaps also with a longer barrel and  2  or 3 thumb screws in the barrel  to hold the eyepiece. This is £16. Ok, I'd pay £20, perhaps even £25 for the adaptation.  There's zero justification for £100+. Oh sorry, there is justification: Ripping off astro buffs.

 

https://www.ebay.co.uk/itm/314709072541?hash=item49461f5a9d:g:SXkAAOSw6vpkhtbq&amdata=enc%3AAQAIAAAA8Cyg9Ul1ZLKTKmgyv1IrlUSTJx0p1OSyxKjXgkqm8bsjwdcVH6zyfJeWf6rh7gI3Qsp%2BRDZ9oQf6fLSQGXMolJ6msRUmnAFnPxjRcyUOuqwbySu1SGOZOhrtBrbpkrr6Z%2Fd1nYqGHN2A4DtbpzxCfh%2F998wyHntllJfsPUBSOoOj4WCaW5Mi4sBYNuIDUt9TB%2BrSg%2BiLS1aQbowQRFMV7HOqXKmUvDa7diOkI7eTA3fS4BZzrVG4JyzVEfIOrcSszKW3yAg7ecOLpxlyqegNZUi8BLMxJTnKZ2HHu1YT2KbH8DpPZhBsL65co%2Fx4aA5GtA%3D%3D|tkp%3ABk9SR4SIh7KrYg

[Mark2022]

2 hours ago, windjammer said:

How about if you packed out the protruding barrel of the eyepiece with layered tubes of plastic pipe (slit the pipe so it can be compressed or expanded to fit over inner /outer layers) until it fits into a 2 inch eyepiece compression adapter.  If the 2" adapter has an M42 or m48 thread at the eyeball end you should be able to finagle your projection hardware onto it.  If the eyepiece barrel is long enough you might get a hose clamp around the pipe to eyepiece barrel as well as the 2" adapter for extra grunt.  Take your point completely about having a lathe for this hobby!

Simon

Invest in a lathe, start a business.  Make a fortune without ripping people off! 🙂 I'd love that! I'm sure Bob with his first knob started that way! And let's face it, they're a bit of a rip off too.

[Elp]

Tbh this applies with anything, not just manufacturing. With the main supplier they'll have their business rate of what they need to charge per hour to cover everything (wages Inc employer contributions, overheads, property commercial rates, energy, depreciation) and this before any profit margin is added. It's not as simple as saying you can just change this and make a few. There's setup times, trials, getting a reliable run going, QA checking, making the parts, all whilst the majority of their main lines are not being manufactured. Turning also requires a number of cuts, you can't just stuff a tool next to some material and expect it to cut, the tool will likely break and mangle the material in the process, you'll be lucky not to damage the tool holder in the process. It all costs. Add in a supply chain to sell the items to the consumer and every link in the chain will have the same and their profit margins. Why do you think most companies try to source from low labour countries, then sell at retail at a higher price? It's all compounding costs as well as a desire for profitability. Larger listed companies have contractual responsibility to their investors (shareholders) so have to perform. It's just how the world works like it or not. If you're lucky you can find an independent whom will do as you desire to be as common sense, not many around anymore though.

Don't get me wrong, I'll try and DIY or do on the cheap where possible as some things are extortionate as you say.

Edited July 15, 2023 by Elp

[Mark2022]

11 minutes ago, Elp said:

Tbh this applies with anything, not just manufacturing. With the main supplier they'll have their business rate of what they need to charge per hour to cover everything (wages Inc employer contributions, overheads, property commercial rates, energy, depreciation) and this before any profit margin is added. It's not as simple as saying you can just change this and make a few. There's setup times, trials, getting a reliable run going, QA checking, making the parts, all whilst the majority of their main lines are not being manufactured. Turning also requires a number of cuts, you can't just stuff a tool next to some material and expect it to cut, the tool will likely break and mangle the material in the process. It all costs. Add in a supply chain to sell the items to the consumer and every link in the chain will have the same and their profit margins. Why do you think most companies try to source from low labour countries, then sell at retail at a higher price? It's all compounding costs as well as a desire for profitability. Larger listed companies have contractual responsibility to their investors (shareholders) so have to perform. It's just how the world works like it or not. If you're lucky you can find an independent whom will do as you desire to be as common sense, not many around anymore though.

I agree with you. I was in manufacturing for most of my career and know full well what's involved. I business managed from end to end. All of what you said  is wrapped up in that £16.99 for that  SVbony item. I'm saying I'd pay up to £25 for what I'm looking for. I'd consider that pretty generous of me.