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Experiments with a Baader Morpheus 14mm


JOC
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When I blew a small fortune on the Baader Morpheus 14mm it was with the knowledge that it came with a top end thread which would take a T ring - thus planting an interesting possibility for photos. 

The moon was up a couple of nights ago and here is the best one of my first attempts.  I am still not happy with the sharpness and think I can improve on this, but to anyone wondering about the possibilities offered by this combo I think you will be impressed with this straight out of the camera shot (no processesing and I've only cropped about 50% of the image so not too much post process 'zooming in') which clearly demonstrates what might be possible with a little bit more practice.  I wonder about the possibilities for Jupiter.  Happy to take comments - this is taken with my unmodded cannon T3 rebel (1100D) Tv setting ISO 100 and I think 1/10th second.  I can't remember if the x2 Barlow was in there - looking at the closeness in the shots it might have been.

 

moon.jpg

Edited by JOC
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Something doesn't seem right.  There so much blurring and chromatic aberrations going on at the edge.  I have the 14mm Morpheus, and I don't see that at the edge with my eye.

Was the camera square on with the eyepiece?  Was eyepiece projection or afocal projection used?  If eyepiece projection, perhaps the projected focal plane is not flat.  Try holding a P&S or cell phone up to the Morpheus to see if you get a flatter field with afocal projection if eyepiece projection was used.

You'll probably never find a DSLR lens with a small enough objective lens for afocal projection.  I use an old Olympus C-4000 from 2002 for afocal projection because it has a 43mm thread on the end of its lens tube and because it still does a decent job.

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1 minute ago, Louis D said:

Was eyepiece projection or afocal projection used?

Woosh!!..........Did you see that fly right over my head?

I haven't a clue what this^^^ means.  I put the Barlow in the focuser, the Morpheus in the Barlow, The T ring on the Morpheus and the unmodded Canon on the T ring - then I used a cable release to press the button.  Is that enough to answer the question?

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Afocal is possible with a DSLR but it defeats the point of being able to remove the lens somewhat I think, it would also be a lot of weight hanging off the focuser so some sag in that is likely.  The weight on the focuser may well be the case of the distortion you can see.

 

I have a few Baader eyepieces all with the threaded connection but for the most part I have found that increasing the separation between the camera and the barlow at prime focus is just as good or better for adjusting the image scale.

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11 hours ago, JOC said:

Woosh!!..........Did you see that fly right over my head?

I haven't a clue what this^^^ means.  I put the Barlow in the focuser, the Morpheus in the Barlow, The T ring on the Morpheus and the unmodded Canon on the T ring - then I used a cable release to press the button.  Is that enough to answer the question?

That's eyepiece projection.  You're using the eyepiece as a camera lens to directly project an image onto the image plane in the camera.  It's likely the Morpheus projects its image in a slightly curved field leaving the edges slightly out of focus.

Afocal projection uses a camera lens with its entrance pupil at the eyepiece's exit pupil to capture an image.  I find it works quite well as long as the camera lens is either a normal to slightly wide angle lens or a zoom lens set to the minimum focal length.  Also, the camera lens's objective lens (the first element incoming light passes through) must be a little smaller than the eye lens of the eyepiece or you will get vignetting (dimming/shadowing and blurring at the edges).  Finally, the eyepiece should have fairly long eye relief so its exit pupil and thhe camera lens's entrance pupil can reach each other.

The camera lens can easily handle a slightly curved image coming from the eyepiece because of its depth of focus.  After all, the world isn't flat, so camera lenses have to be able image multiple image planes in relatively good focus.  Once a suitable camera/lens/eyepiece combination is found, afocal projection yields very good results across the entire field dependent mostly on the quality of the projection eyepiece without regard to how flat a field it projects.  Being that the Morpheus is quite good, the results should be quite good.

11 hours ago, D4N said:

Afocal is possible with a DSLR but it defeats the point of being able to remove the lens somewhat I think, it would also be a lot of weight hanging off the focuser so some sag in that is likely.  The weight on the focuser may well be the case of the distortion you can see.

If the OP had used direct projection (no eyepiece at all) rather than eyepiece projection, I'd agree.  However, eyepiece projection rarely works well except with dedicated projection eyepieces like the Pentax XP line that were designed with flat image fields for projection.  Alternatively, you can also use small copy lenses, microfiche lenses, short focal length photographic enlarger lenses, or photomicrographic lenses rather than eyepieces for the best projection results.  Barring those options, a long focal length orthographic eyepiece might actually work better than the Morpheus.

Focuser sag would cause a linear focus shift across the field, like a tilted closeup lens.  That isn't what we're seeing here.

12 hours ago, JOC said:

the Morpheus in the Barlow

Try taking the barlow out to reduce magnification and the moment arm on the focuser's drawtube (to reduce possible sag) and try again.

13 hours ago, JOC said:

When I blew a small fortune on the Baader Morpheus 14mm it was with the knowledge that it came with a top end thread which would take a T ring

Actually, it's an M43x0.75 thread rather than a T-ring (M42x0.75) thread, so you have to use an adapter between the two.  I assume you have such an adapter or you couldn't have made the connection.

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4 hours ago, Louis D said:

Actually, it's an M43x0.75 thread rather than a T-ring (M42x0.75) thread, so you have to use an adapter between the two.  I assume you have such an adapter or you couldn't have made the connection.

Ah, I didn't realise that a T ring meant something size specific.  Yes, I did buy a special ring that goes between the EP and camera because the T ring that I was using when I just attached the camera directly to the focussers with no EP or lens in place was not the same size as you note here.  FWIW I've taken some cracking shots of the moon with the camera directly attached to the OTA - with a "T" ring, but I am limited in how close I can get unless I zoom in with the PC later. 

4 hours ago, Louis D said:

Try taking the barlow out to reduce magnification and the moment arm on the focuser's drawtube (to reduce possible sag) and try again

I'll certainly try without the Barlow - maybe I was just pushing it a bit to much and everything I add increases the weight and the possible 'saggability'.  I must admit when I looked at all the exposures they all suffered from a lack of quality towards the edges of the shots, so whatever was causing it was constant.  I think I've just got to fiddle with things until I work out how to do it, but I'll have to stick with what I have as I can't afford any more kit at the moment - my spare cash supply has just petered out so I'm quite stuck with what I have.  That said the Morpheus seems a lovely lens and it must be possible to use it to take a nice photo.

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3 hours ago, JOC said:

Ah, I didn't realise that a T ring meant something size specific.  Yes, I did buy a special ring that goes between the EP and camera because the T ring that I was using when I just attached the camera directly to the focussers with no EP or lens in place was not the same size as you note here.  FWIW I've taken some cracking shots of the moon with the camera directly attached to the OTA - with a "T" ring, but I am limited in how close I can get unless I zoom in with the PC later. 

You can also increase magnification by using the barlow by itself if you have a 1.25" to T-thread adapter or if the barlow has T-threads on top as Dan mentions above.  This assumes you're using a 1.25" barlow and not a 2" barlow; otherwise, use this adapter.  How were you able to directly attach your camera to your OTA?  Are there T-threads on the top of the focuser?

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39 minutes ago, Louis D said:

How were you able to directly attach your camera to your OTA?  Are there T-threads on the top of the focuser?

There were a couple of rings that came with the telescope, I unscrewed one that had one of the mounting flanges/collar on that goes into the 2" part of the focusser and attaches with the grub screws (in the same way as the 1.25" EP adapter goes into the 2" bit - in fact it may have been part of the 1.25" adapter - the telescope was sold as possibly taking a camera with a T ring, so maybe this was how they intended it) - I bought a proper T ring that fitted the camera body and this screwed into the bit I had found with the 2" mounting flange on it - thus I get a camera with a short 2" mounting flange collar.  In actual fact I got fed up with constantly unscrewing this useful gizmo and asked FLO if they could possibly get me another.  The great guys there said they had a box of spare parts and had found me one and in exchange for paying postage actually sent it to me FOC - thanks FLO :icon_biggrin:  Thus I have a collar that I can keep constantly screwed into the T ring.  This bit from FLO and my T ring shown in the photos.

Bits.jpg

bits2.jpg

Bits3.jpg

Edited by JOC
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NB.  The Barlow suitably unscrews in a number of places and yes I can attach the camera to the Barlow using the bits I already have.

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I experimented with eyepiece projection a while ago using my Baader MkIII zoom and it's matched Barlow.

Usng the zoom eyepiece at its highest zoom setting then using just the barlow at prime focus with T2 spacers to achieve the same image scale with the barlow gave a better picture.

The Morpheus eyepieces will be superior to the zoom but I think that the extra glass and field curvature are likely to degrade the image compared to using just a barlow.

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4 minutes ago, D4N said:

The Morpheus eyepieces will be superior to the zoom but I think that the extra glass and field curvature are likely to degrade the image compared to using just a barlow.

It sounds like I need an experimentation session :-D

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