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Messages - Don Haines

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946
EOS Bodies / Re: Canon's Medium Format
« on: March 23, 2014, 08:23:28 PM »
I was saying that the same focal length lenses are really not that much larger or heavier.  My mom's 300mm f/4 lens for the 67 format, is 3.4 pounds, and its made of heavy brass.  Yet its image circle allows an almost square sensor dimension that is 70mm wide!  That's hardly cubing the weight of Canon's lighter and more modern designed 300mm f/4 EF lens.  I really don't see this math adding up, to be honest, because you're forgetting that you wouldn't need to match the FOV... 

I'm not sure why you say you wouldn't need to match FoV. A 300mm f/4 lens for medium format is not the same as a 300mm f/4 lens for 35mm. Those are two radically different lenses, by FoV. The entire point is to match FoV, that's why were constantly referring to APS-C crop factors and multiplying lens focal lengths by them...FoV is everything. Assuming a 55x44mm sensor, your crop factor is once again 1.63x compared to FF/35mm. So a 300mm lens for medium format is a 184mm lens in 35mm format.

Going in the inverse, if you are interested in an EQUIVALENT medium format lens to a 35mm 300mm f/4, then you actually need a 490mm f/4 lens for medium format. Now, assuming we use all the same technology that Canon has for their 35mm format lenses, were basically talking about the EF 500mm f/4, albeit with a larger back barrel to support the larger image circle. In this case, a 500mm f/4 lens for medium format is probably going to weigh 7.3-7.5 pounds, vs. the 2.6 pounds for a 300mm f/4. That, as it turns out, is a 2.85x weight difference.

But it doesn't stop there. You have to consider minimum focus distances. A 500mm f/4 lens on MFD is a SHORT telephoto lens, not a long telephoto lens. Minimum focus distance of a 300mm lens on 35mm format is around 55 inches. The minimum focus distance of Canon's 500mm f/4 II lens is 150 inches. You would need a greater optical power to allow a closer focusing distance to actually achieve total parity, which means a greater curvature in the lens elements, which is going to increase the material in each lens element. That will further increase weight.

It's doubtful that the weight of such a lens would literally reach 17.5 pounds (which would be the actual cube of 2.6lb), but it will certainly be much larger and heavier in order to achieve parity with the 300mm f/4 lens for 35mm format. You can't compare 300mm f/4 lenses in both formats...you have to account for the crop factor.


If a medium format sensor say 40 to 45mm wide, has 100 megapixels, then you really wouldn't need to be cubing the weight of a 600mm lens, to get similar magnification at the pixel level, to what you get with the 5D3 with a 600mm lens.  If you don't need the full 100 MP, they could simply adopt Nikon's approach and allow you to shoot in crop mode.  (That would be the common sense approach).  Who cares if the actual focal length is shorter if the pixel size is similar to begin with?

Take a look at the average size and shape of modern medium format digital bodies. They are not only larger in width and height, but they are also considerably thicker, two to three times thicker depending on which sensor back you have installed. The weight of the body itself would be considerably greater than a 35mm format DSLR body. Ergonomically they are not as easy to hold.

And, again, you cannot compare a 600mm lens for 35mm format to a 600mm lens for MFD. Your completely ignoring the crop factor of the 35mm relative to the medium format. You would need ~1000mm lens for MFD to compare to a 600mm.

Additionally, by "just doing what Nikon did", by digitally cropping, you then just have a 35mm frame, so what's the point of having medium format in the first place? The entire point of using MFD is to get the larger FULL frame, not a higher density cropped frame. You want both larger pixels AND more pixels AND a larger sensor diagonal.

These are the reasons that pros, who already use medium format (it isn't something they "will" be using 10 years from now...they HAVE been using it, for decades), use it for studio, portraiture, landscapes, and architecture. These cameras ARE big and relatively heavy compared to 35mm or APS-C format cameras. Comparable lenses ARE larger and heavier, especially those that achieve similar IQ...it's a lot harder, requiring even more precise optics and manufacturing tolerances, to produce bigger lenses that achieve the same level of IQ as smaller lenses. The larger the optical elements, the more difficult it is to eliminate optical aberrations. That's WHY Canon's big white lenses are so expensive...they require much higher grade optical glass, and much tighter manufacturing tolerances, to produce the level of IQ they do. Imagine ALL of your MFD lenses costing that much...
Also, there are scanning backs for 4x5 cameras... They range in price from $10,000 to over $40,000... depending on the resolution... an interesting way to do super high res studio work....

947
Landscape / Re: Please share your snow/ Ice Photos with us in CR.
« on: March 23, 2014, 06:51:43 PM »
Yeh, the snow was hiding.  Honest we still have snow on the ground but that was a south hill exposure.

Now Don, do you actually fry bison burgers or are you pulling my leg?  I've eaten moose burgers that were pretty decent.

Jack

President's choice Bison Burgers..... quite tasty...
http://reviews.presidentschoice.ca/6584/F16848/reviews.htm

And I've got snow! Not a patch of bare ground to be seen and the ice in the river behind the house (Ottawa river) is 42 inches thick!

948
Landscape / Re: Please share your snow/ Ice Photos with us in CR.
« on: March 23, 2014, 06:00:56 PM »
wildlifeandmore, that's a very compelling image with the mountains.  Seeing it I just had to post all I could get today after 2 hours.  Now it did snow yesterday and went below 0 C but try as I might I can't produce proof that there is snow in this scene! ;)

6D 300 X2 640th F6.3 ISO 400  about half frame crop

Jack
Nice picture! I assume the snow was hiding behind the Bison...

I saw some Bison at my place yesterday..... but it was a slightly different scenario :)

949
Animal Kingdom / Re: Show your Bird Portraits
« on: March 23, 2014, 04:11:51 PM »
Bluejay digging through the fresh fallen snow to get at the food. Shot with a SX50 at 1200mm equivalent in the (GASP!) "green box" mode... :)

950
EOS Bodies / Re: Two Cinema EOS Cameras Coming for NAB? [CR1]
« on: March 22, 2014, 04:45:48 PM »
I was looking at the floor chart for NAB. The two biggest booths are Sony and Canon. Sony is in the largest booth, but the next two biggest are both Canon and looks like more total area. The Panasonic booth is about a quarter the size and the Nikon booth is half that again..... the GoPro booth is the same size as Nikon...

With all that space they must be up to something.....

951
Technical Support / Re: More reach
« on: March 22, 2014, 01:15:10 PM »
Hi dhr90.
Personally I had been fairly happy with my 150-500 on my 40D, since I have been pairing it with my 7D I have been rather dissapointed, I have yet to work out if this is operator error, a greater mismatch of AF recruiting AFMA which I have yet to complete, see other posts by me about this!

Cheers Graham.
The Sigma 150-500 (and the 120-400) are very soft lenses. You really notice this when you go from a FF camera (big pixels) to a crop camera (tiny pixels). The 40D has a pixel size close to a FF camera and when you go to a 7D you are now using pixels that are half as large. This has the effect of making the lens even softer.


952
Landscape / Re: jrista et al, Why Astrophotography?
« on: March 22, 2014, 01:07:18 PM »
I have always been fascinated with the night sky. When I go on canoe trips I try to find campsite where I can lie out and stare upwards...  I built a floating platform where I can lie down in the evenings at home and stare upwards.... For me, astrophotography is a natural extension of that fascination.

953
Landscape / Re: Please share your snow/ Ice Photos with us in CR.
« on: March 22, 2014, 12:43:08 PM »
Snow/Ice and Wildlife

Grand Teton National Park along Gros Venture Rd.
5DII
70-200 2.8L IS II
110mm
f/4
1/800
100 iso
Nice Picture....

954
Animal Kingdom / Re: Portrait of your "Best friend"
« on: March 22, 2014, 09:14:53 AM »
Alley Cat.... found as a kitten in an alley... and now enjoying a life of luxury.

955
Animal Kingdom / Re: Show your Bird Portraits
« on: March 22, 2014, 01:48:03 AM »
Peregrine Falcon

Very nice. I don't see them often.
still a little cold in your neck of the woods?
I saw this one in the middle of Ottawa... Thousands of commuters passed by without a clue they were there. ( it was a pair of Peregrines). The duck WAS a Mallard....

It was a warm day, got all the way to plus 2.... And it is now snowing, they say another 15 cm....

956
EOS Bodies / Re: Canon's Medium Format
« on: March 22, 2014, 01:42:54 AM »
An alternative from Canon, where they made a body with a 36x36 size sensor, would be interesting.

That would give a number of advantages:
- 50% area increase
- 27MP with the same pixle size as the 1DX sensor (or 54MP with the same pixle size as the a7r/800)
- All EF lenses would work

If I could get a 40MP-ish sensor, with proper high ISO performance, a fair fps and Canon user interface in a reasonably sized body ... It would put a abrupt stop to my Phase One ambitions ...

I know some will oppose a square image format, but that would be OK with me. Thoughts?

I don't see why that would be any better than just going up a centimeter in each dimension, and making a whole new line of lenses.  It's not as if many couldn't afford to buy new lenses.  And like I said, 10 years from now, it's quite possible they would be making super telephoto lenses to go along with the new mount and larger image circle.  Weight need not be an issue, the physical size of everything would not be much bigger.
Double the sensor and you cube the weight of the lens to get the same field of view.... That's twice as long, twice as high, twice as wide.... Eight times the weight...

These two lenses have the same field of view and F-stop. The small one is from an Olympus 4/3 system and the big one fits Canon FF....a lot of the width of the small one are the focus motors, just look at the lens caps to get an idea of the difference in the weight of the glass....

I, for one, will not be paying for a lens that dwarfs the Canon "big whites"

I agree, I wouldn't want to be using lenses that much larger than the Canon great whites. That said, if Canon ever did enter the medium format market, I suspect they would be serving the same customers as the current offerings in that market: Studio photographers, and possibly landscape and the rare wedding photographer. That's really what medium format services.

Those cameras usually don't even have frame rates much above 3fps, and nothing anywhere close to 10-12fps. Achieving that kind of readout rate would be rather difficult as well. Canon achieved it once with the 120mp APS-H, but as far as I know that was with a special test bench, not an actual camera with existing data storage devices.

If we figured on 4┬Ám pixels, a 44x33mm sensor (the "crop" sensor of the medium format world) would be 90mp. If we figured on a 54x40mm sensor (the size of an IQ180), that would be 135mp. If we also assume 16 bit data, rather than 14 bit, were talking a LOT of data to move around for each frame, 180 to 270 megabytes per raw image. You could get 0.9fps with a single DIGIC5+ (which has 250mbps throughput), and less than 2fps with dual DIGIC5+. You would need something like a DIGIC7+ with some 7x the performance of a single DIGIC5+ to get 5fps at those image sizes, and there is no question you would need MUCH faster memory cards to handle that kind of throughput for a useful continuous buffer depth. Even then, I still don't see such a camera being used for action photography...it would just be too big and unwieldy. Even if it was mirrorless, it's the body and lens size that really kills you at longer focal lengths.
As someone who has hauled around a 4x5 and sherpa'd a 8x10 and even used the kodak disc camera (the iPhone of the film world), I have always thought that 35mm was the sweet spot for ergonomics... Big enough for quality but small enough for portability. In the studio, portability isn't much of a concern so medium format was the hot technology.... And when doing landscapes or architectural nothing touched large format, particularly when you could tilt and angle both the film plane and lens plane to straighten out buildings or warp the focus plane... Sort of like a tilt/shift lens on steroids.....

There is definitely a place for everything, but going to a larger format really makes the size and cost of everything skyrocket... It isn't as simple (or inexpensive) as slapping in a bigger sensor. Your point about file sizes and read speeds hammers in the point.... EVERYTHING is affected.

957
Animal Kingdom / Re: Show your Bird Portraits
« on: March 21, 2014, 11:41:39 PM »
Peregrine Falcon

958
Animal Kingdom / Re: What is this bird?
« on: March 21, 2014, 11:18:11 PM »
Appears to be a red-tailed hawk (although I'm viewing this on my iPhone).

Thanks!
Looks like a red-tailed hawk to me too. They are fairly common in Eastern North America and they do eat squirrels.... I have one that hangs out at work and picks mice out of the fields.

959
Animal Kingdom / Re: Breakfast is Served
« on: March 21, 2014, 10:54:43 PM »
And on today's menu we are having a special on duck......

960
Animal Kingdom / Re: BIRD IN FLIGHT ONLY -- share your BIF photos here
« on: March 21, 2014, 10:52:27 PM »
Ducks taking flight

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