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How should I resolve my birding GAS?

Started 5 months ago | Polls thread
OP User1303423862 Senior Member • Posts: 1,070
Re: How should I resolve my birding GAS?
1

nnowak wrote:

User1303423862 wrote:

My lovely new EF 70-300 IS II USM lens has arrived.

I've been over to the local duck pond to grab a couple of test shots with Larry's handmade 2X TC at shorter and longer FLs and higher and lower ISOs.

Looking pretty good, though not quite as good as the TC along with the 55-250 lens Larry originally calibrated it to. I'm going to have to roll up my sleeves and try to make one specifically for this lens I think. I already have a Kiron optics 2X in Minolta mount I won off ebay for £4. Now I need a 36mm EF extension tube...

Why do you need to handmake a teleconverter when there are plenty of third party EF options on the market that will directly mount to your EF 70-300mm with no modifications? A very quick search on eBay turned up several options under $50.

They won't work with more recent Canon cameras (unless you remove the printed circuit board from inside them).

Anyway, here are a couple of OOC JPGs.

These look pretty soft and low in contrast with color fringing on the edges of highlights. It would be interesting to see similar shots without the teleconverter in place since these sample were only at 94mm and 200mm respectively.

In my experience, it's pretty hard to photograph swan plumage in full sunlight without blowing out the highlights, so I underexposed the shot with respect to the background.
I could mask and recover shadow detail, but these are just quick test shots.

The samples are actually at 188 and 400mm respectively (the TC doesn't report its existence to the camera).

I would be willing to bet that 200mm plus the 2X converter will look worse than a photo at 300mm and cropped to 4500 X 3000 for the same equivalent field of view.

The acid test will be at 300mm + 2X TC downsampled to compare with 300mm cropped to half resolution to get the equivalent FOV. That's what this is really about.

Whilst you're here, and hopefully looking at a bigger screen this time, please have a look at Larry's TC on the 55-250 IS lens and tell me where in the image I need to be looking for the "serious degradation in image quality" you talked about last time.

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Canon EOS R Canon EOS M6 II Canon EF-M 22mm f/2 STM Canon EF-M 28mm F3.5 Macro IS STM Canon 70-300 F4-5.6 IS II +4 more
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