Southern Khao Yai/Nakhon Nayok advice

Are you looking for locations inside the national park, or outside the park?
I only know locations inside the park, but don't know the Southern border areas.
Any specific bird species you are looking for?
There are too many species to just list it here.
I don't know everything, but I visit the park a lot (not in the last month, I'm visiting family in Europe).

Just a tip. If you are a beginning birder it works best to first learn the bird calls. Choose some species you would really love to see and listen to their calls.
Check www.xeno-canto.org/ for bird calls.
As soon as you get familiar with the calls, learn to reconize specific types of birds it will make spotting so much easier.
This season is usually quite interesting with nesting birds.

So if you have any specific target species, maybe I can help to point you in the right direction.

BTW a lens like the Tamron 150-600mm (and for the darker light conditions in the dark) is a must.
The 300mm will come short for most birds.

I was watching the following review on the Tamron 150-600 and this photographer compared it to the Canon fixed 400mm f5.6 (not to mistake with the 100-400mm zoom) which according to these people sells second hand for about the same price as the Tamron, only they say it is quite a bit sharper, even with teleconverter.

Since you say you are into birds, it will hardly ever happen that you would like to zoom out.
The 400mm + 1.4 converter would give you a 560mm lens, and on your 650D body it would compare to a 896mm on a full-frame body.

Though, they say the Tamron is not bad either, but maybe worth to look into this option.
Not sure if you can find a second hand version of that 400mm lens in Thailand, though...

Here's a link to the review on youtube.

While writing this I remembered there is one downside for the 400mm + 1.4 converter combination. The widest aperture will be f/8 which might cause focussing problems with your camera especially in low light. So maybe this was not a good idea after all for the Thai Jungle conditions, haha. Anyway, maybe interesting to look into it... without converter it still compares to a 640mm on a full frame body.

Thats right flip-flops, a minimum aperture of f8 will cause problems with most camera's ability to autofocus. It would become, effectively, a manual focus combination on most camera setups for the lens/convertor combination if min AP is f8.

NN wrote:

Thanks for the info.

Although I'm not looking for any species in particular, I would love to shoot some birds of prey. Are hornbills found in the lower elevations around KY? I've been in forested areas, but the bird life seems more plentiful in open areas and the light is better for photography.

I'm partly writing as an introduction. If anyone is visiting NN pls feel free to contact me. I know the southern border area well. In one area a ranger told me there are bears and in another I saw lot of gaur tracks. I'd be interested in photographing there, but am concerned about safety.

... Hornbills is southern elevations - yes, as long as the forest is intact and there are large fruiting canopy trees and nesting locations, Hornbills will be present throughout. Obviously as you reach border lands were forest is secondary (rather than primary) and recovering from previous logging/denudation, then highly questionable for resident birds.

.... knowledge of NN and associated areas, pls do share any information you may feel relevant or are asked about - its the noble purpose of the site, to share... and inspire others to experience... its great we have you on the forum to share your experiences with others.

I see I had missed your reply...
As I mentioned I'm afraid I can't help you with the Southern side. I usually don't get further South than Haew Narok...
Near Haew Narok it is possible to see Oriental Pied and Wreathed Hornbills. So I expect they should be found closer to the borders.
Like Trekker mentioned the forest needs to be in good state, especially for the larger of these two, the Wreathed Hornbill. Pied Hornbills are also seen in secondary growth, and on the Northern part I've seen them at several kms outside the national park boundary. But that's not so common.
For some reason (probably the not so good state of the forest) I haven't seen many Great Hornbills in the Southern part of the park. But I expect there must be areas with good forest and more chance to see these magnificent birds.

Mountain Hawk-eagle often seems to be in the area around the first viewpoint in the park but on Pak Chong side :( . Crested Serpent Eagles are seen basically everywhere.
I've seen Black Eagles a few times on the grassland at the foot of the Khao Khieo mountain.
One almost guaranteed place for raptors is the bat cave but that's for you also on the wrong side of the park... But nice for pictures when they dive into the endless river of bats. If you haven't seen it yet, then you definitely should!
Though also there it is seasonal. Some species of birds of prey seem to stop by for a couple weeks to gain weight before they continue their migration.

You are right that open areas are easier for photography and for spotting the birdlife, but I would not say that it is more plentiful. The forest is more exciting in my opinion. As soon as you fine a 'bird-wave' it gets hard to decide which species to 'shoot' first.
On birding tours the people hardly ever seem to get deep in the jungle. Just the roadsides are amazing especially early morning or late afternoon. But for me it looses the excitement...

About the lenses. Finding a subject with a long lens is not always easy, though zooming while following a bird in flight is also next to impossible. But if using a tripod it might work.
Practise indeed helps. For a long time I've just always aimed my camera at any living creature I came across and got a lot better at aiming my lens. Though I'm using a 300mm which is a lot easier than longer focal lengths... I'm still outweighing the cons and the pros for my next buy. Versatile zoomlens or sharper fixed focal length... Very difficult decision.