Karim Ghantous Posted July 12, 2021 Share Posted July 12, 2021 6 Set 11 Century 650 ++ Century 650mm f:6,8 (il cannone) diaframmato f:11 più moltiplicatore Leica Apo 1,4x più moltiplicatore Zuiko 1,4x sempre dalla finestra di casa. Attenzione: non è un crop, ci sono tutti i 12 megapixel della EP-L1. IMHO the image quality is better than some photos I've seen, which were taken with native lenses without TCs. Makes you think. 2 Link to comment Share on other sites More sharing options...
rodeo_joe1 Posted July 17, 2021 Share Posted July 17, 2021 IMHO the image quality is better than some photos I've seen, which were taken with native lenses without TCs. Makes you think. It certainly makes me think. If my rudimentary Italian is correct, it's also claimed to be taken through the window of the guy's house! At an effective aperture of f/22 to boot. The shutter speed isn't given, but IME anything much longer than 1/30th s is going to give noticeable motion blur, unless a tracking equatorial mount is used. So the ISO must have been quite high as well. However, it's difficult to tell how sharp it really is from that tiny Flickr thumbnail. It looks nowhere near as sharp as this example taken with the same model of lens, for example. Link to comment Share on other sites More sharing options...
Rick Helmke Posted July 18, 2021 Share Posted July 18, 2021 Joe I think it’s interesting that the photo in your link is quite good but the guy who shot said he needed a better camera and greater crop factor. I wonder how much better he thinks it can get. Rick H Link to comment Share on other sites More sharing options...
Karim Ghantous Posted July 18, 2021 Author Share Posted July 18, 2021 It looks nowhere near as sharp as this example taken with the same model of lens, for example. Seems to me like it's sharpened a bit too much. But overall it's not a bad image, despite the CA. The link I shared has the ISO listed as 100. Joe I think it’s interesting that the photo in your link is quite good but the guy who shot said he needed a better camera and greater crop factor. I wonder how much better he thinks it can get. Rick H Maybe a Fuji GFX with a modern super telephoto + TC. Even with a 1.4x TC, you can make a Sony or Nikon lens, for example, to project a sufficient image circle. I haven't yet seen anyone use an SLR supertelephoto on a medium format sensor. Link to comment Share on other sites More sharing options...
rodeo_joe1 Posted July 19, 2021 Share Posted July 19, 2021 Maybe a Fuji GFX with a modern super telephoto + TC. I doubt that would get you any better image than using a smaller sized sensor. To fill the 33mm image height of a GFX, you'd need a ridiculous focal length of 3,660mm. So even if you have a more realistic 1000 mm lens + 2x TC, you're still only projecting an image of the moon just over 18mm in diameter. That takes up an area of just under 17.6% of a GFX 100 frame, or 17.6 megapixels. The same 1000mm lens + 2x TC actually over-fills a 16x24mm 'DX' frame, but takes up nearly 29.6% of a 24x36mm frame. So if we attach it to a 60 megapixel Sony A7Riv, we get a moon image covering 17.74 megapixels, and the Sony wins. That's always assuming the 1000mm + TC image quality is worthy of those 17.74 megapixels to start with..... And that's a pretty big assumption. Link to comment Share on other sites More sharing options...
rodeo_joe1 Posted July 19, 2021 Share Posted July 19, 2021 Seems to me like it's sharpened a bit too much. But overall it's not a bad image, despite the CA. The link I shared has the ISO listed as 100. The same model of lens was used. I doubt that adding two teleconverters and shooting through a window actually improved the image quality or reduced the CA! Link to comment Share on other sites More sharing options...
JDMvW Posted July 19, 2021 Share Posted July 19, 2021 I doubt that adding two teleconverters and shooting through a window actually improved the image quality or reduced the CA! Could it be?? mirabile dictu! :D Link to comment Share on other sites More sharing options...
Karim Ghantous Posted July 20, 2021 Author Share Posted July 20, 2021 To fill the 33mm image height of a GFX, you'd need a ridiculous focal length of 3,660mm. So even if you have a more realistic 1000 mm lens + 2x TC, you're still only projecting an image of the moon just over 18mm in diameter. That takes up an area of just under 17.6% of a GFX 100 frame, or 17.6 megapixels. That is a good point. The narrower the AOV, the smaller the sensor you want. (That's my rule-of-thumb for general photography). The same model of lens was used. I doubt that adding two teleconverters and shooting through a window actually improved the image quality or reduced the CA! Yes, that is logical. But, it appears that the CA remained the same. Link to comment Share on other sites More sharing options...
q.g._de_bakker Posted July 20, 2021 Share Posted July 20, 2021 That is a good point. The narrower the AOV, the smaller the sensor you want. (That's my rule-of-thumb for general photography).Doesn't make sense to me. For any given angle of view, narrow or wide, you scale the focal length with sensor size. An supposing same pixel density and sufficient resolving power, larger sensors give more detail. So unless you want to crop in camera to help get a narrower angle of view, and do not care much about detail, i would not want to use that rule of thumb. Link to comment Share on other sites More sharing options...
Karim Ghantous Posted July 21, 2021 Author Share Posted July 21, 2021 Doesn't make sense to me. For any given angle of view, narrow or wide, you scale the focal length with sensor size. In theory, sure, there's nothing wrong with that. But personally, I prefer an E-M1 with a 300mm lens over an A9 with a 600mm lens or a GFX with a 750mm lens. Link to comment Share on other sites More sharing options...
httpwww.photo.netbarry Posted July 31, 2021 Share Posted July 31, 2021 I think they look pretty good with 2 ice's. I don't think they look over sharpened, you think? Link to comment Share on other sites More sharing options...
rodeo_joe1 Posted August 1, 2021 Share Posted August 1, 2021 Doesn't make sense to me. For any given angle of view, narrow or wide, you scale the focal length with sensor size. An supposing same pixel density and sufficient resolving power, larger sensors give more detail. So unless you want to crop in camera to help get a narrower angle of view, and do not care much about detail, i would not want to use that rule of thumb. Yeah, everybody has an optically perfect 3660mm f/5.6 lens lying about for use on their 33x44mm sensor camera. Get real q.g. Or better still... post a picture or two. Link to comment Share on other sites More sharing options...
William Michael Posted August 1, 2021 Share Posted August 1, 2021 . . . However, it's difficult to tell how sharp it really is from that tiny Flickr thumbnail. It looks nowhere near as sharp as this example taken with the same model of lens, for example. Flickr allowed me to download the 'original' from the link Karim posted (4032x3024) and yes that image does not appear as sharp as the image in the link that you posted. WW Link to comment Share on other sites More sharing options...
glen_h Posted August 13, 2021 Share Posted August 13, 2021 Vivitar 500mm catadioptric on a D200. No TC on this one, but I have used them. -- glen Link to comment Share on other sites More sharing options...
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