Messing About With a Teleconverter

[Rob Wood (Admin)]

Testing out what my new el cheapo 70-300 does when I put a 2x teleconverter on it. This one is hand held at max range, f5.6, 1/500th sec and a very noisy 2500ISO. Was fun to push what it’s capable, but far from ideal results. lol

[d_rec]

Do you loose light when using one of these(similar to extension tubes)? What about auto-focus – that stops at about F/5.6? I need the reach one day when I decide on my next Lens addition….. A converter could let me get something a little shorter like 70-200mm compared to maybe a 120-400 range. Think it’s still early in the dream stage though.

[Rob Wood (Admin)]

Yeah, you do.

The autofocus works, but it’s so slow and clunky that I just used manual focus.

I dunno – it’s fun to mess around with things like this, and I think I could probably get some ok results with a bit of practice and planning, but I think the downside (at this focal range) really outweighs the benefit of magnification.

[Mark Pashia]

I recently bought the Canon 1.4X teleconverter just to get an idea of what it could do on my Canon EF 100-400mm lens. Canon’s teleconverters only work on their prime lenses over 100mm and on this one zoom lens. However, on the zoom it won’t auto-focus because the lens needs to be capable of f/4.0 or better since you lose one stop of light and the EF100-400mm is f/4.5 at 100mm and f/5.6 at 400mm. The 2X loses two stops of light so auto-focus goes out even faster. Manual focus on my Canon XSi is not good with my bad eyes, so I have to go into “live view” and zoom in to 5x to get any idea of a sharp focus and this is a really slow process that does not lend itself to wildlife. The one exception is that I recently watched two hawks mating and found their nest. Once babies are hatched, I will try working from a blind near the nest and hope that the teleconverter will help “reach” out that far. Only time will tell, but I won’t work the nest until the 28-32 days of incubation are over for fear that the parents will abandon the eggs. By the way, the teleconverter is not a waste since I have the EF 500mm f/4.0 super telephoto on my wish list to save for! That might take a while though.

[Astaroth]

I’d spent a lot of time writing an ask about teleconverters (with my English level :p), and now I’ve seen you already had written about them :p!

Then, don’t you recommended it for me? I have a TAMRON 70-300mm (f/5.6 at 300mm) and I want use it for wildlife (birds, for example). I need large focal lengths… but I need speed too and I prefer don’t spend all my money in a too much expensive new lens :p!

Maybe a less multiplier factor works better… I don’t mind autofocus (I never use it), I mind the speed and the sharpness.

[Rob Wood (Admin)]

Hmm, well you lose speed and clarity, so probably not. You’re not going to get awesome shots (the one above was one of my better attempts!)

But if you can get a cheap one off ebay, then get it and play. Sometimes you can get them very cheap out of Hong Kong.

[Astaroth]

Thanks @admin :)! I’ve seen very cheap telescopes for reflex too (about 800mm, f/8), but I don’t know if the image quality is very bad with them…

Maybe I must practice for take better pictures with my 300mm and save money for a good lens in the future… in a far far future xD!

[Rob Wood (Admin)]

I have seen those Opteka 800mm f8 lenses for about $150. But when I look at reviews they are REALLY poor. It is very tempting to risk $150 though. 🙁

[Astaroth]

I’ve been looking for optekas all the day xD! I’ve seen the Opteka 800mm f/8, the Opteka 500mm f/8, The Opteca 500mm f/6.3…

Firstly I thought that Opteka was not so bad option… but some people tell me that crop a image from my 70-300 is better than a complete pic from opteka 800…

Rarely I’ll can spend more than $250 in lens… Is Opteka send my (little) money to trash?, it is?

I hope win the lottery soon xD!

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