Stacking TC's with different cameras tech question

OK I am not a lens resolution tech wiz. But I was thinking about my buddy reewik always having great results with stacked TC's and he uses a 4MP 1D. I was thinking maybe this doesn't put as much of a burden on the lens resolving power as say a 1DSMkII might? Follow me? So in other words could he get better results with stacked TC's than someone with a hi megapixel camera where the sensor is already pusing the resolving power of the lens more?

Anyway maybe a tech wiz can clear this theory up for me right or wrong. Heck this might not even make any sense

I am just that good..

Very measurable effect on a 20D.

EF 200mm f2.8L with TCs, EF 300mm f4L IS with TCs

The 20D has a nyqusit limit of 78lp/mm so all being equal a 4Mp camera will have a nyqusit limit of 54 lp/mm. After anti-alias filtering and capture sharpening they can probably resolve say 65 and 45lp/mm respectivly.

Tests show double stacking TC with the 200 f2.8 and 300 f4 IS lowered the MTF50% resoloution to 30-36lp/mm (which is like a very bas wide angle lens wide open) in the centre so I would think this loss of fine detail was observable if he looked close enough.

Contrast drops badly also which should be easy to spot. However if he is using one of the big telephotos like the 300 f2.8 I understand these cope with double stacking quite well.

Interestingly it is still worth doing resolution wise compared to upresing (specialy if you can stop down a couple of stops), although the actual quality is not great depending on how big you want your prints.

Lester Wareham wrote in post #2016605
The 20D has a nyqusit limit of 78lp/mm so all being equal a 4Mp camera will have a nyqusit limit of 54 lp/mm.

Of course, the sensor of the 20D and the 1D is not the same size (1.6x vs. 1.3x). Did you take that into account in your calculation?

Best regards,
Andy

Lester Wareham wrote in post #2016605
Very measurable effect on a 20D.

EF 200mm f2.8L with TCs, EF 300mm f4L IS with TCs

The 20D has a nyqusit limit of 78lp/mm so all being equal a 4Mp camera will have a nyqusit limit of 54 lp/mm. After anti-alias filtering and capture sharpening they can probably resolve say 65 and 45lp/mm respectivly.

Tests show double stacking TC with the 200 f2.8 and 300 f4 IS lowered the MTF50% resoloution to 30-36lp/mm (which is like a very bas wide angle lens wide open) in the centre so I would think this loss of fine detail was observable if he looked close enough.

Contrast drops badly also which should be easy to spot. However if he is using one of the big telephotos like the 300 f2.8 I understand these cope with double stacking quite well.

Interestingly it is still worth doing resolution wise compared to upresing (specialy if you can stop down a couple of stops), although the actual quality is not great depending on how big you want your prints.

I am very aware of the image quality loss, contrast loss, etc of using TC's. My simplified question is "Can you get better results with stacked TC's on smaller sensor/megapixel cameras because those cameras do not push the leses as much" It looks like from above you are saying that is somewhat true especially if you stack lets say a 1.4X TC and a 2X TC together like reewik does. He does it using the 400 5.6 and the 1D camera with good results.

I'd say no.
The degree of impact on the lower res camera may somehow be less, but at the same point your starting with a lower res image in the hopes of lessening this impact. Combine the impact with the allready reduced res, and overall you have a lower quality image.. no matter how good Reewik is

In essence your saying "the 1D 4.5MP is so bad allready you won't notice that terrible effect of the TC"

Now I know that is not what you mean literally, but this is it in essence.. and it may have some truth, but really the first part "it's so bad allready" means that it in the end the images won't be as good as using a camera that is more effected by the t-con.

CyberDyneSystems wrote in post #2016899
I'd say no.
The degree of impact on the lower res camera may somehow be less, but at the same point your starting with a lower res image in the hopes of lessening this impact. Combine the impact with the allready reduced res, and overall you have a lower quality image.. no matter how good Reewik is

In essence your saying "the 1D 4.5MP is so bad allready you won't notice that terrible effect of the TC"

Now I know that is not what you mean literally, but this is it in essence.. and it may have some truth, but really the first part "it's so bad allready" means that it in the end the images won't be as good as using a camera that is more effected by the t-con.

No I think the 1D is making some great images. I have seen some of reewik's full size pics and they are excellent. I just thought that the sensor is not pusing the lenses as far as a high megapixel camera. Thus I thought the 1D is much more able to take TC's without degrading the image as much as a camera that is already pushing the lens further (ie a 1DSmkII or 5d).

Anyway my theory was that a lower resolution camera can take TC's and do it without as much image degradation as a higher resolution camera because the higher res cameras are already approaching resolving power of the lens.

So the low resolution camera can 'tap into' that extra resolving power with TC's while the higher megapixel camera's cannot.

I'm not technical enough on this issue to prove or disprove this theory so that is why I posted it here!

I know Arthur Morris uses the 1DSMKII with stacked converters all the time and has some incredible images.... I liked his response..... I know nothing about what you are asking.... I just shoot the pictures and if I like them I keep them.

Andythaler wrote in post #2016710
Of course, the sensor of the 20D and the 1D is not the same size (1.6x vs. 1.3x). Did you take that into account in your calculation?

Best regards,
Andy

opps , still that makes it even easier to detect the IQ.

morehtml wrote in post #2016774
I am very aware of the image quality loss, contrast loss, etc of using TC's. My simplified question is "Can you get better results with stacked TC's on smaller sensor/megapixel cameras because those cameras do not push the leses as much" It looks like from above you are saying that is somewhat true especially if you stack lets say a 1.4X TC and a 2X TC together like reewik does. He does it using the 400 5.6 and the 1D camera with good results.

No I think it should be detectable.

morehtml wrote in post #2014028
... So in other words could he get better results with stacked TC's than someone with a hi megapixel camera where the sensor is already pusing the resolving power of the lens more?....

The 1D's pixel pitch is 10.8 microns, compared to the 400D's 5.7 microns. So shooting a 400D is like using a 1.89x TC without light loss. That's equivalent to 257% more pixels throwable at the target with the 400 D than the 1D when using the same lens, at the same distance, without TCs and the range is already focal length limited.

Granted that the 1D's pixels have better unit performance (DR, etc.), but from the crops I've seen, the quality of the 400D's pixels is good enough for me. Given a choice, I'd prefer a 400D + 500 mm shot than a 1D + 500 mm + 2x TC one (both have near equivalent "reach" reckoned from pixel pitch, with the 1D setup just a bit longer).

Romy

OK so looks like the consensus is no