KOWA eyepieces plus Contax SL300RT (1 Viewer)

I only joined the forum a couple of weeks ago and I seem to have done nothing but ask questions! I have to say however that the feedback I get is great and very useful.

To get a semi serious start in digiscoping I bought a KOWA TN823 scope and a Contax SL300RT camera. I have started off with a 32xw eyepiece with the scope, plus the KOWA digiscoping adapter, which is giving good results, but it becomes quickly aparent that the best results are acheived when the camera lens is not being zoomed. I am therefore considering additional outlay on a KOWA 20 - 60x zoom eyepiece to get greater magnification without using the camera zoom.

So - my question is does anyone have direct experience with a KOWA zoom eyepiece attached to the Contax camera? (or failing that with a Nikon CP4500). How well does it work? Is there any vignetting at zero camera zoom etc?

The eyepiece is quite narrow compared to the 32xw. Also it is longer and requires an extension to the KOWA digiscoping adapter. Does anyone know how well this works?

Any info or feedback before I shell out another couple of hundred quid or so will be most welcome.

Thanks, Barry Boswell.

Barry,

Sorry for not answering you earlier although I have had both the Kowa 32x and the zoom - and even tried them both in digiscoping. IanF and I have had slightly differing experiences from similar equipment - but as Ian is a lot more experienced digiscoper than I, he knows this better in practice.

At the risk of giving conflicting advice I would say that for the reasons you mentioned, I probably wouldn't buy the zoom. I agree with your notion that usually the less you zoom with the camera, the better the images. I would even continue by saying that the same applies with the scope zoom. In this case the main problem may actually have been the poor eye-relief of the 32x, which forces you to zoom the camera quite a lot in the first place. The Kowa zoom is a very nice eyepiece but it too suffers from poor eye-relief - especially at higher magnifications (=any power above 20x) - and again you have to zoom in with the camera to remove vignetting.
It is tempting to think that you could take advantage of the 60x of the zoom, but the result is actually the same as when you use the extreme camera zoom: soft images. The zoom may work better at 20x than a 32x fixed, but that you didn't ask - and at that power Kowa has now better eyepieces for digiscoping.

There are some general guidelines for good images in digiscoping:
1) Get close to the target.
2) Use small magnifications in the scope (20-30x).
3) Use low camera zoom settings ("yellow flower" in CP4500 macro setting).
4) Use aperture priority exposure. Stop down the camera a bit, if the light permits - usually it doesn't.

OK, I didn't recommend the zoom for digiscoping (now that you already have the 32x), but if you like the versatility of the zoom in birdwatching it may well be a good purchase. The Kowa 20-60x zoom is a quite popular eyepiece and I think you should be able to find one to try yourself - even I have sometimes problems to understand what I want to say in my posts

Good luck,

Ilkka

Hi Barry, much of what Ikka says is valid but I would expect you would find the 20-60x zoom at magnifications of around 20x more useful than the 32x... it will let in more light @ 20x and allow faster shutter-speeds to greeze the action and any movement at the scope/camera end. I used to use the old Kowa zoom for the tsn3/4 series scopes, this was widely regarded as a poor eyepiece but at 20x it produced great results. I'm not overly familiar with the 800 series zoom.

In general you will always get some vignetting with the camera at full wide angle. Most modern zoom eyepieces go into wide angle at higher mags so you get minimal vignetting at 20x, then more vignetting as you go up to 30x and then it opens out again at the top end of the eyepiece magnification... which you shouldn't really be using for digiscoping anyway.
regards,
Andy

Is your 32X the old type? if so consider the new 32x or the 21x I recently bought both and they give zero vignetting at any zoom setting with the cp4500. The 32 is also slightly wider than the old one and a touch sharper, in my opinion the new lenses make the Kowa scope a match for any other) and better than most for digiscoping. This is one of my first photos using it and its better than anything I was achieving with the old lens

Hi Dennis, been offline for about 5 weeks due to dodgy computer and rubbish company that have been trying to replace old steam driven puter.

Now have go faster puter, bins, and scope, you still have a great picture of Squacco and i agree that your Kowa is spot on intend to replace my camera next so will keep an eye on all contenders.
cuddy

Excellent shot,Dennis

KOWA eyepieces

Many thanks to everyone for their responses. I am getting some experience but it is a fairly steep learning curve. I do understand that the closer you can get to your subject, and the less zoom in general you can use - then the better the results. In fact I have a CP8700 camera with a 1.5x telefoto lens which gives 12x optical zoom plus 4x digital zoom which gives good results because the 8 meapixels allows plenty of cropping. I purchased some "proper" digiscoping gear because I wanted to go further.

The new KOWA 32xw eyepiece gives good results with no vignetting at all on the Contax camera, which is great, but I was trying to get an angle on the best way (if any) to get adequate results at greater magnification when it was not possible to get as close to a subject as one would like - which seems very often. For obvious reasons I do not want to spend out a lot of money on a zoom eyepiece if I cannot get any more out of it than the 32xw that I have at the moment.

Anyway, a couple of results below that I have managed to get so far. All tweaked a bit in paintshop pro - mainly because the sun has not shone much recently.

Barry Boswell

Barry Boswell said:

The new KOWA 32xw eyepiece gives good results with no vignetting at all on the Contax camera, which is great, but I was trying to get an angle on the best way (if any) to get adequate results at greater magnification when it was not possible to get as close to a subject as one would like - which seems very often. For obvious reasons I do not want to spend out a lot of money on a zoom eyepiece if I cannot get any more out of it than the 32xw that I have at the moment.

Click to expand...

If you get unvignetted images with your new 32xW, you would probably be disappointed with the vignetting you get with the old-design zoom eyepiece. Of course I may have had a poor unit, but my experience was that the image quality suffered more from using the eyepiece zoom than that of the camera (CP4500). IIRC someone has calculated that approximately 40-45x is the optical resolution limit for a 80 mm scope and the eye (and for a digicam even less); above that you don't actually resolve any more details.

Digiscoping is powerful, but its limits are quite easy to reach. :t:

Ilkka

iporali said:

If you get unvignetted images with your new 32xW, you would probably be disappointed with the vignetting you get with the old-design zoom eyepiece. Of course I may have had a poor unit, but my experience was that the image quality suffered more from using the eyepiece zoom than that of the camera (CP4500). IIRC someone has calculated that approximately 40-45x is the optical resolution limit for a 80 mm scope and the eye (and for a digicam even less); above that you don't actually resolve any more details.

Digiscoping is powerful, but its limits are quite easy to reach. :t:

Ilkka

Click to expand...

Thanks for that Ilkka. From the feedback I got I had already decided not to go ahead with the zoom eyepiece but to persevere with the 32xW for the time being.

Incidentally I bought a second hand CP4500 off Ebay and my initial impression is that it does take better pictures than the Contax, even though there is very slight vignetting at wide angle.

Barry Boswell.