I don't see any problem with the photos. You will get a much shallower depth of field with the 2X TC but the thin depth of field where it is sharp it looks fine.
What is it that you find wrong with the TC images?
Paul.
Only thing I can suggest is that the 80ED prime crop is more exposed than the DOI crop, maybe you need to use exposure compensation (try -1.3 to -2), I find that the case when I use my TCs at the same subject, as there is more light tones in the prime shot.
My Miranda 75-300mm arrived today. It's in mint condition and still in the box, seemed a shame to take it apart but I got stuck in straight away. Used my usual method of sticking a big lump of Blu-Tac to the front element and gave it a good twist. That unscrewed easily and then I used the same method to unscrew the telenegative group. Working like this means it can all be reassembled in the future and nothings been damaged in the removal process.
The telenegative part is in it's own metal housing and the glass has a lovely blue/yellow coating as you move it in the light. On the scope it performs just as well as the Vivitar one I tried last week.
Even though this lens is 300mm the magnification is about the same as the Vivitar 210mm so there was no extra gain from getting a more powerful lens. I'd say the Miranda gives around 2.3X and the Vivitar fractionally less at about 2.2X.
Nice bit of glass and again it's a very cheap way to get a quality teleconverter for using on the scope.
Strong wind here today so no birds around but I photographed this Ladybird from around 12m away. Came out nice and sharp, you can even see all the veins on the leaf.
Paul.
LOL...of course nothing wrong with the one with TC. But it's nothing better than the one without TC. Without the TC, I can get to have Focus confirm (though seldom use), more lighting or higher SS, less shake (vibration), less sagging on the camera due to another extension, better DOF for more allowance of missed focus during speedy focusing, and when taken, crop to higher magnification (for web use only) but still came out with an as good pic if not better than one taken with TC. The only advantage I see with TC is the closer view during focusing thus allowing better composition. Correct me if I were wrong.
Paul, as usual, your shots always amaze me. Can you run a test. Shoot something not that far away, say 20-30m, but smaller object. Try it using different TCs (DIY, Barlow, telenegative etc) and SW80ED only, crop all of them to show that object only. All taken from the same distant with similar condition. Which one would be better? Luckily UK is a bit far, otherwise you will one day find me knocking on your door wanting more ideas about DIY.
Paul, you're getting great results out of those lenses, no doubt.
One question, are these parfocal like a TC? Or do you have to adjust focus when adding it?
This is where experience comes in. There will be a distance where the TC (or any device for high magnification) will start to perform better than cropping, but it's all dependent on the size of the subject. There's so much overlap that I can't say "at this range such and such will be best". Even at 10m a small bird will be better with a 1.4X TC than just the scope.
Paul.
Stunning shots Paul. So much details. What are their shutter speed and ISO? C an't wait for my 2 zooms to arrive.
Fernando, the telenegatives aren't parfocal. Two of mine are only about 1/4 turn away from being in focus and the other is about 1 whole turn.
Didnt think about using the front element as an eyepiece, but it makes a cracking loupe.