A Question (1 Viewer)

I've been following this forum with interest for a few weeks now. For birding, I currently use a Nikon D90 with a Nikon 300mm f/4 AF (not A-S) lens and a Tamron 1.4x TC and (occasionally) a Nikon TC-201 2x converter. The TC-201 gives me a manual focus 600mm f/8 lens with focus confirm in good light. As I expect everyone knows, longer Nikon lenses get *very* expensive even for manual focus. The question is, should I consider one of the 80mm f/7.5 astro scopes? Would I see any appreciable improvement over the 300mm/TC-201 combination? If not, what type of scope should I be thinking of as a possible step up? (OK, that's three questions, sorry).

Thanks in advance,

John

Aegea said:

Would I see any appreciable improvement over the 300mm/TC-201 combination? If not, what type of scope should I be thinking of as a possible step up? (OK, that's three questions, sorry).

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The 80mm F/7.5 is by far the best price to quality ratio out there, of course if you're willing to spend considerably more money, you'll find better scopes, specially mechanicaly.

The ED80 againt the 300 F4 with a 2xTC? The ED80 will amaze you, I had two of those lenses, actually sold my last one last week. With the ED80, you'll get much better image quality, less CA, better contrast, much better resolution, overall a superior image clarity that will blow the 300 F4 away. Also much better light gathering, more than F/8 vs F/7.5 would imply.

I haven't decided myself on a real stepup yet, I'm considering trading mine for sometime now, but I find it hard to find something that justifies the exchange. A real step up for bird photography would be something with a better F ratio, but the available choices with better Fratio are either shorter, or without FPL53, not that much faster or extremely expensive...so for now I don't think you can get that much better, at least optically.

Here's some of alternatives, if they're worth the price or not for this use, I have no ideia:
http://www.teleskop-express.de/shop...--Carbon---2-5--Moonlite-fuer-Vollformat.html

http://www.teleskop-express.de/shop/product_info.php/language/de/info/p1834_.html

http://www.teleskop-express.de/shop...2_TS-ED-APO-100-600mm-f-6---2-5--focuser.html

http://www.teleskop-express.de/shop...500mm-f-5-5---fast-optics---2-5--focuser.html

There's also the WO Megrez 110, I you don't mind something a little bigger.

Welcome aboard Aegea. The guys here have convinced me into taking the scope (80ED in particular) route. Still waiting for my scope to ship from Germany. Your 300mm and even with the 2X TC, are only good for garden birds. Lets journey together with the scope.

Fernando, that is quite a list of scopes but they'll burnt right through my pockets. Didn't know that you are selling off your scope otherwise I wouldn't need to hunt down sellers willing to ship here...LOL. So you are going for the speed ... I almost wanted to go after the SW 100ED or 120 ED, but the gain in speed at that range aren't substantial, but I do gain a lot of size and weight. Thus I settle for this one http://www.astroshop.eu/celestron-telescope-ap-80-600-ultima-80-ed-ota/p,7900#tab_bar_2_select . That include VAT. So for them to ship to me without VAT, it's only 398.42 Euro.

alphan said:

Fernando, that is quite a list of scopes but they'll burnt right through my pockets. Didn't know that you are selling off your scope otherwise I wouldn't need to hunt down sellers willing to ship here...LOL. So you are going for the speed ... I almost wanted to go after the SW 100ED or 120 ED, but the gain in speed at that range aren't substantial, but I do gain a lot of size and weight. Thus I settle for this one http://www.astroshop.eu/celestron-telescope-ap-80-600-ultima-80-ed-ota/p,7900#tab_bar_2_select . That include VAT. So for them to ship to me without VAT, it's only 398.42 Euro.

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Well, I've been selling my scope for two years now || but I never got the guts to do it in the end.
I would have to try one of these scopes first to make that trade, specially the 600mm F/6 witch is the one interesting me the most, spending that much money and not being fully pleased is something I don't want.

The speed is important off course, F/7.5 vs F/6 is an half stop increase, that's usually a costly improvement, just like on any photo lens (300 F4 vs 300 F2.8 for example), alltough on reality the differences in shutter speed aren't that great, basically in low light I'll be shooting at 1/160 vs 1/100... Is it worth it? Every bit helps, but is a lot of money for that difference.

The real improvement will be on focus, with a dandelion chip and using trap focus, using a scope like this will be nearly no different than using an AF lens, but for that you really need at least a F/6.3 scope. I tried that on the ED80 but the F/7.5 only allows me to use the central AF point, even then if the light goes too low the camera can't focus. With the F/6 scope I can focus in everypoint at nearly every light, and it focus almost as well with a 1.4tc than the ED80 without.

I'm trying a ED70 F/6 scope now with a dandelion on, and I can tell you is really nice and easy to focus this thing with the dandelion. Not that I had a lot of trouble focusing without the chip, but it's a great improvement, having the hability to only shoot when the subject is focused is a very nice thing to have.

Off course optically, this scope is nowhere near the ED80 league, there's a good bit of CA comparing with the ED80 that have zero or close to it. Sharpness and contrast is still great though, much better than the 300 F4.
If that 600mm F/6 is about the same as the ED70 in CA, there's no way I'm trading my ED80. Off course it's a diferent F ratio, is not only the lack of FPL53, if I stop down the ED70 to F/7.5 the CA is nearly gone, but that would defeat the purpose.

Fernando and Alphan, thanks for the feedback. I think you have convinced me to go ahead and try an astro scope.

Unfortunately, I'm afraid that list of scopes is a bit rich for my pocket also, the Williams 90mm goes for about $1200 new, and the TS Optics don't seem to be easily available on this side of the Atlantic. The common budget brands here seem to be Orion, Sky-Watcher, and Vixen.

At this point, I think I will start looking for something like a used 80mm f/7 or f/7.5 to experiment with. There seem to be a couple of astronomy sites that have active classified ad sections and reasonable prices.

I've successfully chipped a couple of old manual focus lenses with Dandelion, and I would definitely go that route with a scope, although Nikon does give focus confirmation without a chip.

BTW, you can see my wildlife shots on Flickr as jl22182. Most of the recent ones were taken with the Nikon 300 and the Tamron 1.4x TC.

Thanks again!

Fernando, when I was using the SP500f8, it had an AF Confirm chip which can either just lit a green LED or give a beep (with AF on) when in focus. With the LED, I seldom see it lit as my eye would be concentrating on the subject. With the beep, whenever the shoot button is pressed, the motor would be scanning. It's both annoying and draining my battery. Unless, the bird is sitting still and I can leisurely do my focusing.

My aim for scope is to better fill my pic frame at closer range than my AF 200-500 Tammy. I were told that scope will better handle TC than zoom lens thus the 600 7.5 are not long enough. I would most probably extended to X2 or more thus focus confirm ore out of question. I would have gone for something longer yet able to Focus Confirm but alas, they are just too expensive and big for any practical use.

Good luck with your search. We'll be keeping track of your adventure LOL.

Aegea, the cheapest ones using the FPL53 glass would be either Skywatcher or Celestron . I did found a supplier in US with a reasonable price tag but they do not ship out of the States. Googles around and I am sure you can get something reasonable. Bear in mind that for birding use, you only need the OTA and focuser (without the diagonals, eyepieces, reducer, guide scope etc) which will make it cheaper than the whole thing.

I never use the light for that exact matter, I want to keep the eyes on the shutter not the light. About the AF motor, with the dandelion the motor doesn't move, so that's not a problem.

Of course with TCs you're out of luck. But I don't usually have problems getting close to most birds, most of the times I use camouflage, the only birds I shoot without camo is waders and I can drag my self pretty close to them. I never went for the scopes for long range shooting, I use them as I use any other lens, I went for scopes for the image quality, I would never afford a lens that could give me this quality shooting from the same distance.
But there's no doubt I wouldn't mind focus confirmation with a TC on

Fernando, my mistake....you're not on Sony cam.. Only Sony camera are body motor driven.... Where I am, I find AF Confirm works at f8 most of the time. My f6.3 + 1.4TC on works when very bright and not in the shadow.

Actually, Nikon is motor driven too, or was as all new lenses have built in motors now.
The camera body motor moving is an issue on my D90 with the chip from the Cosina lens I have on the ED80, being an old AF lens the D90 tries to move it, I have to get around that by enabling the AF-on button function.

So does the ED80, even in the shade AF sensors works most of the time, but with the central point and if the subject has at least minimal contrast, if I switch to the other points it doesn't, unless in strong light and a very contrasty subject.

Same scenario here, only spot metering. I still have my AF confirm M42 adaptor and will try it when my scope arrive before deciding whether I should make it Focus confirm. I think it will be more down to how my scope perform. If I can crop the pics at 600mm and still get good result, then no need for additional TC and I can have a dandelion stuck there.