[GarethC7]

I'm leaving for a trip to Ecuador in 10 days and the longest lens that I will be bringing with me (but not carrying all the time) is the 300/4 A. I'll be shooting landscapes and people mostly but there may also be an opportunity to shoot some birds and wildlife. These aren't my main interest so I'm not hung up on having the absolute right gear for this but was wondering if you would use the 2x TC with the 300mm or just shoot with 300mm while there.

I do have the 2x TC and it's not the greatest piece of gear Pentax have ever manufactured so am a bit torn. I won't be editting until I get home so it's a decision for prior to departure probably.

[UncleVanya]

I would shoot some test shots myself.

[PJ1]

Which 2x TC do you have? Some are better than others. While it is often said that most TCs are no better than shoot-and-crop (and some may be worse), I think you have to take the in-body SR into account. Unless you are shooting from a tripod, you can dial in 600 mm for SR and that should be an advantage. I find a TC better than shoot-and-crop when I am shooting hand-held.

[marcusBMG]

Take the tc and a bean bag. I bet there'll be a couple of occasions where it'll mean you get an ok shot of something which is otherwise too far away.

[GarethC7]

I'll have a tripod so I'll probably use it as a monopod and fix the ballhead for some steadiness if that helps in the decision.

[672]

I would shoot and crop . I say this not due to image quality but due to looking through a very dim view finder with the TC attached makes that critical telephoto focus near impossible in all but the most direct sunlight….

[marcusBMG]

I'll have a tripod so I'll probably use it as a monopod and fix the ballhead for some steadiness if that helps in the decision.

Not really how I was thinking at all... I envisage a long range something (animal, nest... ) where you have time and opportunity to set up and get the focus using aids like live view/focus peaking (you haven't mentioned your camera), 2 secs timer and MLU...

I would shoot and crop . I say this not due to image quality but due to looking through a very dim view finder with the TC attached makes that critical telephoto focus near impossible in all but the most direct sunlight….

which goes most of the way to answering your point (which as a generality I agree with...)

[yurihuta]

I'm leaving for a trip to Ecuador in 10 days and the longest lens that I will be bringing with me (but not carrying all the time) is the 300/4 A. I'll be shooting landscapes and people mostly but there may also be an opportunity to shoot some birds and wildlife. These aren't my main interest so I'm not hung up on having the absolute right gear for this but was wondering if you would use the 2x TC with the 300mm or just shoot with 300mm while there.

I do have the 2x TC and it's not the greatest piece of gear Pentax have ever manufactured so am a bit torn. I won't be editting until I get home so it's a decision for prior to departure probably.

There is a matched (also works with some other 645 lenses) 1.4x converter that might offer better image quality and is slightly smaller, although does not give the reach of the 300mm + 2.0x combination.

Where in Ecuador are you headed?

If the Amazon, then a 645 300mm might be a tad short unless you hit hotspots like mineral licks (Amazonia birding tour: Parrot clay licks at the Napo Wildlife Center | Napo Wildlife Center) where group shots might work well with the 645 300mm.

If the Galapagos, then the 645 300mm might be just fine as the wildlife is more habituated to humans.

[GarethC7]

We'll be spending a few days in Otavalo and then on a big anti clockwise loop to Latacunga, Tena, Banos Pappalacta so ahlf of it in the Amazon and half through the Avenue of Volcanoes basically.

[PhilRich]

My experience with this lens and the 1.4x is that cropping does not equal the quality when using the tele converter.

[Ed Hurst]

Although not the same lens (I use the 6x7 300mm f4 EDIF), my experience has also been that using the 1.4x converter beats cropping for quality, though the same cannot be said for the 2x.

[GarethC7]

Trouble is I don't have the 1.4 TC I tested the 2x a bit yesterday on the 400 as the light was fading to give myself a better idea and it really seems like putting the lens cap back on. I needed an iso of 6400 to equal 800 for shutter speed and fstop, very surprising to me. I'll probably bring it as the incremental weight is negligible when I throw the other 16 tonnes of glass in the bag!

[UncleVanya]

Trouble is I don't have the 1.4 TC I tested the 2x a bit yesterday on the 400 as the light was fading to give myself a better idea and it really seems like putting the lens cap back on. I needed an iso of 6400 to equal 800 for shutter speed and fstop, very surprising to me. I'll probably bring it as the incremental weight is negligible when I throw the other 16 tonnes of glass in the bag!

This is another consideration when comparing cropped vs TC. If ISO has to go up, that impacts picture quality.

[yurihuta]

We'll be spending a few days in Otavalo and then on a big anti clockwise loop to Latacunga, Tena, Banos Pappalacta so ahlf of it in the Amazon and half through the Avenue of Volcanoes basically.

If in Tena for a while some spots that might be worth investigating are Amazoonico (wildelife rehabilitation center - amazoonico rescue center) and Yanayacu (cloud forest, bring macro! - one spot that has trails and researchers that could help locate specific species http://www.yanayacu.org).

Amazoonico is a nice place with the chance to see and study some behaviours of species that are difficult to see in the wild when on a compressed schedule.

[bull drinkwater]

the Pentax 645 tc's are so good that I don't hesitate to use both the 1.4 and the 2.0. I use them with the 465 200mm and 400mm, also the 6x7 300mm. as I onlt shoot in daylight, I have no problem with the viewfinder. at times I even stack them.