July 26, 2014, 03:18:33 PM

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Messages - AlanF

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31
Pricewatch Deals / Re: Is that Legit? Canon 24-105 Lens for 681$.
« on: July 02, 2014, 05:50:58 PM »
There is so much bashing of the 24-105. Yesterday, because of all the reports about the sharpness of the Tamron 24-70mm f/2.8 I tried one out against my 24-105, with every intention of buying. The 24-105 was sharper than the Tamron. Maybe I have an exceptionally sharp 24-105 or the Tamron was a bad copy.

32
EOS-M / Re: Cheap 400mm advice
« on: July 02, 2014, 06:51:27 AM »
The best cheap way of getting 400mm is the Sigma 400mm f/5.6 apo tele macro. Some work only at f/5.6, others work stopped down. I had a good one which worked at all apertures cost me about £130 on eBay, but I recently sold it for about £375 on eBay, and someone got a really good lens. They are sharper than the 400. You can compare this shot with my previous - it's beaten only by my 600mm combo.

33
EOS-M / Re: Cheap 400mm advice
« on: July 02, 2014, 05:45:47 AM »
Why do you want to take photos of the moon, especially low resolution ones? If all you want is the moon,
here are some images from when I was comparing lenses on the 5DIII and the SX50. You would do much better with the SX50 than a moderate 400mm on the 5DIII. The 600 (300mm/2.8 II + 2xTC) was the best for me. From top to bottom 100-400mm, SX50 at nominal 1200mm, 600mm, and Tamron 150-600 at 600mm. (The Tamron was taken, obviously, at a different time, and under more hazy conditions and at a poorer phase for seeing detail).

34
It is so easy to cycle with the lens at the ready. I use the Canon supplied strap through the lugs of the lens, sling the shoulder section round the right hand side of my neck with the camera and lens dangling at the left hand side of my waist. The camera and lens don't waggle around too much while I am cycling and I can quickly stop and swing the camera up for a shot. The twin lugs hold the lens much better than does a Black Rapid, which is fine for walking but not for cycling. I have a nice cycle ride to the lab and take the 300+TC with me regularly in the hope of seeing something worthwhile.

35
Lenses / Re: Stacked TCs - 1.4x III + 12mm Extension Tube + 2x III
« on: June 30, 2014, 12:27:02 PM »
What does sharpness being reduced 50% mean? Does that mean with 2x+1.4x relative to bare lens? Since adding a 2xTC can increase resolution by a maximum of x2 and a 1.4xTC by a maximum of x1.4, it doesn't look as if you are gaining anything by stacking them.

You've got a point. But remember the 2x extender increases the pixels on target by 4x. 2x in two dimensions, if that makes sense (so, say the bare lens gave you a subject 1000x1000 pixels, that would be 1MP; doubling the focal length gives you 2000x2000, which is 4MP).

It has a couple of advantages I would say. First, it makes the subject bigger in the viewfinder, which can help if you're focusing manually. Second, if you were to crop to the same size the noise patterns would be different. again it's hard to put into words. But shrinking down an image taken with a longer focal length would reduce the appearance of noise, whereas simply cropping to give the same field of view at a shorter focal length makes the noise more apparent.

In my subjective view, 2x + 1.4x does give extra resolution. Beyond that, you're not gaining any extra details, but the above points hold (the big exception being stacked astrophotography, where you regain all that resolution by combining multiple images, so any extra focal length is good).

In terms of number of pixels, sure doubling f means you get 4x more on target. However, if you halve the the resolution in 1 dimension you lose 2x2 = 4x in two dimensions. So, you have got nowhere. Now mackguyver has just found that adding the 1.4 to the 2x lowers the sharpness from 80 to 50%, ie by a factor of 1.6, for an increase in f of 1.4x. So you have actually moved back in resolution for a loss of autofocus and aperture.

36
I get my share of very sharp close ups, seeing the barbs on the feathers, the rings around the eyes etc. But, it is just as much fun catching a scene at low resolution. On Saturday I went for a walk with my son and grandson and saw for the first time fledgeling barn owls, which I have been trying to see for the past 5 years, but always missed them. Here they were and I was able to swing the 5DIII and 300mm/2.8 + 2 xTC into action hand held (iso640, 1/320, f/5.6). You can't get closer than about 50-60 metres, and you could barely make them out by eye. But, here is a nice memory, and my son immediately took it as a screen saver. Went back yesterday with my new monopod for assistance, but the birds were gone again.

Their faces occupy only 90x90 pixels. Without the 2xTC you would hardly resolve their eyes.

37
This shot taken with 300 ii +2xiii not cropped ,love how sharp compared to my 100-400 but did get some nice shot with that lens too

Not cropped! How did you get so close?

38
Lenses / Re: Stacked TCs - 1.4x III + 12mm Extension Tube + 2x III
« on: June 30, 2014, 06:41:51 AM »
I finally had a suitable subject to try the stacked extenders - in this order (1.4x III + 12mm Extension Tube + 2x III) and I had some trouble with focus because the tree the owl was on was moving, but I found with IS on, I was able to do a good job using the viewfinder.  It was too dark in the shade to use LiveView unfortunately, but I did use a cable release & tripod.  CA was minimal, but contrast was reduced around 25% and sharpness probably around 50%.  It's still a very usable image for anything 8x10 and smaller - here's the full photo, uncropped:




What does sharpness being reduced 50% mean? Does that mean with 2x+1.4x relative to bare lens? Since adding a 2xTC can increase resolution by a maximum of x2 and a 1.4xTC by a maximum of x1.4, it doesn't look as if you are gaining anything by stacking them.

39
Lenses / Re: Stacked TCs - 1.4x III + 12mm Extension Tube + 2x III
« on: June 30, 2014, 12:46:01 AM »
Was the order camera 1.4x III + 12mm Extension Tube + 2x III lens or lens 1.4x III + 12mm Extension Tube + 2x III camera?

40
These are beautiful images by all accounts.  I do see slight iq degradation, especially in looking at the fine details in the feathers and hairs of the animals, compared with what the 300 2.8 II can do alone.  I don't know how much of this is due to downgrading of the image to get posted. 

I would be proud to take these pics, don't get me wrong, but I really love when you can see every hair, or very fine feather quill and vein.

sek
You would lose even more fine details without the 2xTC. You have to get twice as near without the TC to resolve the same level of detail. I like also to capture every detail of feathers, but you have to get close enough to do so, and the 2xTC lets you do it at twice the distance. 

41
Lenses / Re: Any word on the 50mm with Image Stabilzation?
« on: June 29, 2014, 03:42:51 PM »
I have asked in the Review thread of the 35A whether people are still happy with the lens but with no reply. If other people are having problems with the 35A I'll give it a miss.

42
Software & Accessories / Re: DxO Optics Pro 9, Elite Edition
« on: June 29, 2014, 12:24:04 PM »
"export DxO as a jpeg and then open with PS"

Blasphemy!  If Thou intend to further edit in PS then Thou shalt export in a lossless format!  Be this the proclamation!

Your grammar is worse than blasphemous: Thou intendest, not Thou intend; to edit further, not to further edit (no split infinitives are to be found in the works of Shakespeare, Spenser, Pope, or Dryden, or in the King James Version of the Bible).

Fair enough  :P

Good sport! And I agree that for serious editing lossless is better, but I usually do minor stuff in PS.

43
Software & Accessories / Re: DxO Optics Pro 9, Elite Edition
« on: June 29, 2014, 11:16:27 AM »
"export DxO as a jpeg and then open with PS"

Blasphemy!  If Thou intend to further edit in PS then Thou shalt export in a lossless format!  Be this the proclamation!

Your grammar is worse than blasphemous: Thou intendest, not Thou intend; to edit further, not to further edit (no split infinitives are to be found in the works of Shakespeare, Spenser, Pope, or Dryden, or in the King James Version of the Bible).

44
Software & Accessories / Re: DxO Optics Pro 9, Elite Edition
« on: June 29, 2014, 10:25:55 AM »
Does DxO do anything special when it exports to LR? (I don't use LR so don't know what this is about). I just export DxO as a jpeg and then open with PS.

45
Software & Accessories / Re: Apple to Cease work on Aperture
« on: June 28, 2014, 03:08:17 PM »
DxO PRIME NR is truly remarkable.

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