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Image quality help (1 Viewer)

Hi Frank!
At last we can all see what's holding you back - a diabolical eyepiece!! Throw it away immediately and get a Pentax one, even if you have to rob a bank!
Both these shots illustrate perfectly that you are only achieving focus and clarity in the central part of the frame, then the surrounding area goes out of focus in a circular fashion outwards.

TD,

Hmm, interesting comments. So what you are saying is that only a Pentax XW eyepiece will give me good digiscoping results? None of the other manufacturer's Astro eyepieces will work? Out of curiousity, why exactly? Because of the field flattening effect? After buying and utilizing the Siebert 19 mm I thought I made an improvement in the quality of the pictures. Are you saying that even it isn't worthwhile for this endeavor? Do I have to have a Pentax XW to get the best results? Any comments would be appreciated.

Here is a shot from this morning. It is an oriole at the top of a pine from about 20 yards.
 

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FrankD said:
TD,

Hmm, interesting comments. So what you are saying is that only a Pentax XW eyepiece will give me good digiscoping results? None of the other manufacturer's Astro eyepieces will work? Out of curiousity, why exactly? Because of the field flattening effect? After buying and utilizing the Siebert 19 mm I thought I made an improvement in the quality of the pictures. Are you saying that even it isn't worthwhile for this endeavor? Do I have to have a Pentax XW to get the best results? Any comments would be appreciated.

Here is a shot from this morning. It is an oriole at the top of a pine from about 20 yards.
Hi again Frank!
Of necessity all comments I make are obviously only personal opinions. I am very much hoping that someone else will jump in on this one to either back me up or shoot me down.
To simplify, it is MY opinion that any astro eyepiece will not be suitable for terrestrial digiscoping. It is also MY opinion that a Pentax eyepiece designed specifically for this particular scope for TERRESTRIAL use will give you the best results. If however there are other manufacturers who make TERRESTRIAL eyepieces for this scope, the chances are that they will beat the one you are using hands down.
Next, I am not an optics expert but yes, the flattened field is a major benefit and I would imagine that other optical correction elements would be encompassed in a terrestrial lens (will an optics expert please clarify this?!)
I read in a previous thread of yours someone advising that the less elements (glass) an eyepiece has the better. I could not DISAGREE with this more. This MAY be true for astronomical use, but for terrestrial use it certainly isn't. Each element of a lens is performing a certain task, be it to change the direction of the light rays, magnify them or alter their characteristics. Also different types of glass within a complex help with the latter.

Finally I think you are so damn lucky to have such fabulous birds on your doorstep! This particular picture illustrates something we've all had with autofocus, and that is the 'focus on branch in front first' syndrome. This is the type of situation where IF you get the time, manual focussing would have helped. There's a helluva lot more to digiscoping than the average person thinks and even though I've been a photographer for years, I'm still learning the digiscoping business!
Timedrifter
 
TD,

Your comments are appreciated and I will take them to heart. One question though, what benefit does a more flattened field give if a majority of folks are typically zooming in with their digital camera 2-3x to get a larger image of the bird. Most of the eyepieces I have used give a flat, focused field for at least the center 1/2 of the image. The birds typically are well within that center portion so I am trying to understand why the extra area in focus would be of any benefit.

Thank you again.
 
Just to join in with Timedrifter, I was also horrified when viewing your 2 photos of the birds on the lawn. It looked as though you had got everything right as far as focus and setup. But the picture quality was not at all what it could so easily have been.

To see blurring worsening radially like that was a shock. Something in your optical chain is NOT good!

If we assume the Camera is okay, and if the objective lens in your scope is ok, then it must be the eyepiece.

A daft question, but are all the lenses really clean?
From video work of old I remember smearing vaseline on an old lens to create that effect.

I did read up on the differences between astronomical and terrestial scope lenses a few months back, but must admit have forgotten it all. Suffice it to say, the important bit I remembered was a note to myself, to use the right one.

I am quite an experimenter and will try anything, so there must have been some major issue that was relevant.

When I splashed out for a HDF opticron eyepiece & objective lens, I was truly amazed at the difference it made over my cheaper scope.

But having said that, I get very results with my cheap binos. It seems as if that at low magnification - 8x or 10x, the optical issues are not 'quite' as critical. But anything over 15x shows up poor optics very quickly. And at 30x + very serious kit seems to be needed for pro type results.

Now where are all the birds hiding around here!!!
 
FrankD said:
TD,

Your comments are appreciated and I will take them to heart. One question though, what benefit does a more flattened field give if a majority of folks are typically zooming in with their digital camera 2-3x to get a larger image of the bird. Most of the eyepieces I have used give a flat, focused field for at least the center 1/2 of the image. The birds typically are well within that center portion so I am trying to understand why the extra area in focus would be of any benefit.

Thank you again.
Hi again Frank!
I've been trying hard to decide how to answer this question. I think it will be best to divide the answer into questions for yourself to answer. Firstly, do you think that all your pics will have the bird nicely captured in the centre of the frame? If the bird fills the whole frame in a situation where you're at zero zoom, do you walk away to a position where only the centre portion is occupied by the bird? Finally are you really happy to see all the area surrounding the bird badly out of focus? I believe that if you give this some more thought you will come up with several more situations where to have the WHOLE of the frame in focus on a single 'plane' is beneficial.
You may at this stage in your interest be looking only at the bird, but eventually you will, as others do, look at the surrounding image as well. Digiscoping frequently has an extremely limited depth of field and it certainly helps if the area to the left and right are in focus even if everything in front of and behind that 'plane' are not.
ATB
Timedrifter
 
TD

I agree perhaps this isn't the best place for discussing this so I think I will start a thread for A620 settings to help me with my quest. It has been a while since anyone posted somthing for this camera, so I will see what comes back. I'll put in the set up there for you, watch this space.

Thanks again
 
DB, TD,

Again, I am glad for the candidness and will consider the suggestions and questions pondered. At the moment the Pentax eyepiece isn't an option but it may be shortly. I guess that will be the only way to surely know if the eyepiece truly is the problem or if it is the camera.

All lenses were clean by the way and I would eventually like to consider more than just the bird in the picture.
 
FrankD said:
DB, TD,

Again, I am glad for the candidness and will consider the suggestions and questions pondered. At the moment the Pentax eyepiece isn't an option but it may be shortly. I guess that will be the only way to surely know if the eyepiece truly is the problem or if it is the camera.

All lenses were clean by the way and I would eventually like to consider more than just the bird in the picture.
Hi Frank!
I think firstly its extremely unlikely to be the camera, and secondly you won't have any regrets about buying the Pentax eyepiece! I for one will keep watching this thread, waiting for your first results which I know will make you more keen than ever.
For now good birding and keep taking the pics, because camera familiarity can sometimes be the deciding factor regarding getting a pic or not!
Timedrifter
 
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