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Author Topic: Beyond 400mm  (Read 16887 times)
cmox
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« on: March 30, 2009, 10:35:57 AM »
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This is an invitation to discuss about lenses with a focal length beyond 400mm.

Today, not everybody wants to spend much money on the super telephoto lenses made by the camera manufacturers. They are excellent, but very expensive. When it comes to focal lengths of 500mm these primes cost a fortune, beyond 600mm they cost even more.

I use an old Novoflex lens with a Leitz Telyt 6,8/560mm head, often with a 1.5x or 2x converter. This lens is long and heavy, but that does not bother me. The main problem is that f6.8 is not much, and it is a manual focus lens. Focussing at 6.8 is well possible, an adapter with "focus confirmation" for my EOS helps.

Discovering the world beyond 560mm is different...enter the converters. Imagine a focal length of 1120mm at f/16. The image quality is acceptable but not great, and it really takes times and energy to use this combo. Just imagine me carrying two big wooden tripods (6 Kilos each), a 5 Kilo lens plus the camera. MLU, a wind deflector, cable release. It takes 10 minutes to setup and 10 more minutes for focussing one single shot, it's like using a 4x5" camera.

Here is an old, analog, unsharpened example:



1/30 at f16, 3,600 feet distance.

I could imagine that I am not the only one looking for sharp, affordable alternatives.

What do you use for long distance shots?
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dalethorn
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« Reply #1 on: March 30, 2009, 11:10:54 AM »
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Quote from: cmox
This is an invitation to discuss about lenses with a focal length beyond 400mm.
Today, not everybody wants to spend much money on the super telephoto lenses made by the camera manufacturers. They are excellent, but very expensive. When it comes to focal lengths of 500mm these primes cost a fortune, beyond 600mm they cost even more.
I use an old Novoflex lens with a Leitz Telyt 6,8/560mm head, often with a 1.5x or 2x converter. This lens is long and heavy, but that does not bother me. The main problem is that f6.8 is not much, and it is a manual focus lens. Focussing at 6.8 is well possible, an adapter with "focus confirmation" for my EOS helps.
Discovering the world beyond 560mm is different...enter the converters. Imagine a focal length of 1120mm at f/16. The image quality is acceptable but not great, and it really takes times and energy to use this combo. Just imagine me carrying two big wooden tripods (6 Kilos each), a 5 Kilo lens plus the camera. MLU, a wind deflector, cable release. It takes 10 minutes to setup and 10 more minutes for focussing one single shot, it's like using a 4x5" camera.
Here is an old, analog, unsharpened example:

1/30 at f16, 3,600 feet distance.
I could imagine that I am not the only one looking for sharp, affordable alternatives.
What do you use for long distance shots?

I would think that at this distance, atmospheric distortion could be as great or moreso than lens distortion.
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cmox
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« Reply #2 on: March 30, 2009, 11:44:19 AM »
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Quote from: dalethorn
I would think that at this distance, atmospheric distortion could be as great or moreso than lens distortion.

One simple rule with these lenses ist: if you want sharp images, don't photograph on a hot day at noon. It's much better in the early morning.
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Roger Calixto
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« Reply #3 on: March 30, 2009, 04:47:04 PM »
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I'm actually more curious as to what subject warrants such a zoom? Obviously you're not going for wildlife @ f16 early in the morning. I'm not being sarcastic, just curious. 1120mm is alot!

{}
KT
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If my day job wasn't so cool, I'd quit and be a photographer =)
Geoff Wittig
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« Reply #4 on: March 30, 2009, 04:56:13 PM »
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Quote from: cmox
This is an invitation to discuss about lenses with a focal length beyond 400mm.

What do you use for long distance shots?

Roger Hicks has published several interesting articles on the same subject, with the same conclusion; that a reasonably sharp but slow old Leitz Telyt was good enough for his infrequent use. Given how good modern D-SLR's are at higher ISO, it's possible to get surprisingly good results with such a lens, provided you have plenty of time to focus and aren't shooting anything moving.

There's always a distinction between "the best you can get" and "good enough". I do own a Canon 500 f:4 IS L lens, and it is indeed incredibly sharp. Autofocus and IS are great, and with enough light to keep the shutter speed up the results are terrific. Image quality is almost as good with the 1.4x L teleconverter. However...despite all that magnesium construction and its relatively light weight, it still feels like you're handling a bazooka made of glass. Bringing it with you is a commitment, not an afterthought.

For everyday use I still find myself turning to Canon's relatively elderly 100-400 f:5.6 IS zoom. It's reasonably compact, reasonably light, reasonably handy...with perfect technique and a heavy hand pressing it down on the tripod, sharpness at the long end is...well, not too awful. I do find the ability to fine-tune the focal length very useful for landscapes. I don't even try to use it with a teleconverter. It does best with images that don't depend on intense acuity, like the one attached. It's often worth simply trying to get closer and using a shorter, sharper lens shooting through less air.
« Last Edit: March 30, 2009, 04:57:34 PM by Geoff Wittig » Logged
wildlightphoto
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« Reply #5 on: March 30, 2009, 09:58:57 PM »
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The 560mm f/6.8 Telyt suits me fine.  I'm using the Leica-mount version which is light enough to carry on day-long hikes and not regret having brought it.  Sample photos:

http://www.wildlightphoto.com/560r68.html

Its primary disadvantages are a curved field (not a problem with most wildlife) and a manual aperture (I use it wide-open most of the time).
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JamesA
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« Reply #6 on: March 31, 2009, 01:10:09 AM »
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Quote from: dalethorn
I would think that at this distance, atmospheric distortion could be as great or moreso than lens distortion.


Distortion is caused by heat waves or variations in air density so the air acts like a distorting lens.  Three things determine how much it effects your image:
1.  The diameter of the front element of the lens.  The wider, the worse it is.
2.  The magnification that lens produces, more = worse.
3.  The shutter speed you use to record the image.  This can help or hurt the image, depending on the air mass you are shooting through.

The longer the air mass (distance) you shoot over, the worse the effect.  Shooting over heat sinks (things that reflect heat or release it) is the worst.  Concrete, heated buildings, roadways, they are all bad.
Early morning is probably the best time, with mid-day and late evening being the worst because of heat (solar) reflection and re-radiating.  Shooting over grassland, forest or (best) water is the best way to avoid heat distortion.
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cmox
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« Reply #7 on: March 31, 2009, 02:34:03 AM »
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Quote from: kingtutt
I'm actually more curious as to what subject warrants such a zoom? Obviously you're not going for wildlife @ f16 early in the morning. I'm not being sarcastic, just curious. 1120mm is alot!

{}
KT

Many of my stories are environmental subjects. What you see in the photo is a chemical factory near an airport that will be relocated due to airport expansion plans. As you can imagine, chemical factories, airports etc. are not enthusiastic supporters of photographers revealing their sins.  

Well, and I shoot landscapes.
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250swb
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« Reply #8 on: March 31, 2009, 10:30:32 AM »
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To my mind I think you have to give it to Olympus if you want a balance between 'top' 400mm plus tele lenses and 'good enough' in one camera system.

There are two, the 300mm (600mm equiv) f 2.8, a large lens for Olympus at 3290 grams (and 5000) and the 70-300mm (140 - 600mm equiv) f4 - 5.6 at just 620gm (and 299), and it fits in your pocket. Naturally the consumer grade 70 - 300mm isn't a patch on the 300mm, but even so its plenty 'good enough' for a double page spread. The big downside is that its a slow f5.6 at the 300mm end. The irony is that the whole setup of a 70-300 is smaller, lighter, and cheaper even adding a body to use it with, than most if not all 600mm lenses on their own.

Steve
« Last Edit: March 31, 2009, 10:32:02 AM by 250swb » Logged

cmox
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« Reply #9 on: March 31, 2009, 02:47:14 PM »
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Quote from: 250swb
To my mind I think you have to give it to Olympus if you want a balance between 'top' 400mm plus tele lenses and 'good enough' in one camera system.

If I had not purchased an EOS 5D2 recently...full format, 21 MP... I know Olympus has built many good lenses, and I heard of a 11/1000mm lens for the old OM series.
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Ray
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« Reply #10 on: March 31, 2009, 08:00:07 PM »
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For me, the main advantage of the APS-C format has always been the facility to extend one's longest telephoto lens by a factor of 1.6x. A 400mm lens effectively becomes a 640mm lens in terms of FoV on the Canon cropped format. In fact, the existence of the Canon 100-400 IS lens was a major attraction for me when I switched from Minolta to Canon several years ago, although I didn't buy a 100-400 until I'd bought a D60.

It's relatively light, certainly hand-holdable and portable, flexible because of its zoom range, and has the advantage of IS. It's a puzzle why Canon does not upgrade this lens. Increasing sensor pixel density is fine. However, if you don't also increase lens resolution, the benefits of the increased pixel desity tend to be small.

I can't help wonder what the problem is. Is it really so difficult to design a 100-400 F5.6 zoom that is sharp at full aperture and at F8? If you compare the 50% MTF results for the Canon 100-400 IS with the 70-200 IS at Photozone, you can see that the 70-200 has much better resolution at any focal length. The 100-400 IS is sharpest in the middle of the range, around 200mm, as one might expect. However, at this focal length it's still not nearly as sharp at the 70-200 fully extended. In fact the 70-200 is sharper even at F11 where all lenses tend to be equally bad.
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wildlightphoto
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« Reply #11 on: April 01, 2009, 07:33:15 AM »
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Quote from: Ray
For me, the main advantage of the APS-C format has always been the facility to extend one's longest telephoto lens by a factor of 1.6x.

I don't understand the logic of this.  How is throwing away almost half of the lens' image circle an advantage?  Given sensors of equal pixel density and quality I'd rather have more of the image circle to work with (and a bigger viewfinder) and crop as needed.  IMHO this "advantage" is a case of camera makers convincing buyers that its lemons are really lemonade.
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pegelli
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« Reply #12 on: April 01, 2009, 08:16:49 AM »
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Quote from: telyt
I don't understand the logic of this.  How is throwing away almost half of the lens' image circle an advantage?  Given sensors of equal pixel density and quality I'd rather have more of the image circle to work with (and a bigger viewfinder) and crop as needed.  IMHO this "advantage" is a case of camera makers convincing buyers that its lemons are really lemonade.

I would agree with your logic if the body cost was equal, but usually the same pixel density FF cameras are at least 3x more expensive vs. their APS-C counterpart. You obviously lose some lens resolution vs. an equal MP count FF sensor, but with good glass the difference isn't that huge since you're only using the best part of the image circle, and even these bodies are quite a bit more expensive vs. APS-C with the same pixel count.

I know you can't have everything and FF (and MF) do have their place, but for an amateur on a budget APS-C and 4/3rd formats are not bad choices
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pieter, aka pegelli
cmox
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« Reply #13 on: April 01, 2009, 09:21:56 AM »
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Quote from: pegelli
I would agree with your logic if the body cost was equal, but usually the same pixel density FF cameras are at least 3x more expensive vs. their APS-C counterpart. You obviously lose some lens resolution vs. an equal MP count FF sensor, but with good glass the difference isn't that huge since you're only using the best part of the image circle, and even these bodies are quite a bit more expensive vs. APS-C with the same pixel count.

I know you can't have everything and FF (and MF) do have their place, but for an amateur on a budget APS-C and 4/3rd formats are not bad choices

It is actually quite simple: for someone who has no digital camera yet there is a choice, and the high crop factor might be a feature that changes his mind when it comes to buying.

If someone already has a new 21MP FF camera like me, that is not really an attractive option.
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Ray
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« Reply #14 on: April 01, 2009, 09:30:37 AM »
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Quote from: telyt
Given sensors of equal pixel density and quality I'd rather have more of the image circle to work with (and a bigger viewfinder) and crop as needed.  IMHO this "advantage" is a case of camera makers convincing buyers that its lemons are really lemonade.

Of course you would, and so would I. When full frame 35mm cameras reach the pixel density of the cropped format cameras, there's absolutely no image quality advantage in respect of one's longest telephoto lens, with the cropped format. The only advantage, as Pegelli mentions, is the lower cost and weight of the cropped format.

However, Canon FF sensors are always behind the cropped format in terms of pixel density. The 1Ds2 has the same pixel density as the 6 year old 6mp D60, and the 1Ds3 and 5D2 have the pixel density of the 4 year old 20D. The 50D has almost double the pixel count of the 20D. For a full frame sensor to match the pixel density of the 50D, it would need 39mp, the pixel count of the P45+.

The other issue is edge performance. All 35mm lenses have noticeably worse performance at the edges of the 35mm full frame. The Canon 100-400 IS has much better edge performance on a cropped format camera. However, even on a cropped format, there can be noticeable resolution fall-off in the corners.

Recorded image resolution is always a combination of sensor resolution and lens resolution. If you increase either one, you inevitably increase image resolution, by at least some degree. Whether or not that increased resolution is noticeable on a print of a particular size, is another issue.

Sensor resolution is limited by its pixel count. There's a fairly sharp cut-off point at the Nyquist limit, in absolute terms. In practical terms, the cut-off point is reached before the Nyquist limit. In other words, we're talking about 2 1/2 to 3 pixels per line pair in a Bayer type array.

Lenses do not have such a sharp cut-off point with regard to resolution. They keep on resolving more and more detail, but at an increasingly lower contrast. Even at F16 a lens can resolve 100 lp/mm, but at just 10% of their original contrast.

Since image resolution is always a product of lens resolution and sensor resolution, if you keep increasing one without increasing the other, the advantages in respect of recorded image resolution become less and less relevant. There's a law of diminishing returns at work.

The Canon 100-400 IS is 'out-resolved' by the 50D. It needs upgrading. A good quality EF-S 100-400/f5.6 would be fine    .
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pegelli
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« Reply #15 on: April 01, 2009, 09:35:35 AM »
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Quote from: cmox
It is actually quite simple: for someone who has no digital camera yet there is a choice, and the high crop factor might be a feature that changes his mind when it comes to buying.

If someone already has a new 21MP FF camera like me, that is not really an attractive option.

Fully agree, and I would add one more. If someone already has a decent MP count APS-C body he also has a choice, keep it or upgrade to FF. There the financial difference is even bigger.

Quote from: Ray
However, Canon FF sensors are always behind the cropped format in terms of pixel density. The 1Ds2 has the same pixel density as the 6 year old 6mp D60, and the 1Ds3 and 5D2 have the pixel density of the 4 year old 20D. The 50D has almost double the pixel count of the 20D. For a full frame sensor to match the pixel density of the 50D, it would need 39mp, the pixel count of the P45+.

True, but for Nikon and Sony the difference is almost negligible. An APS-C size crop from the D3x and A900 is 11 MP while the D90/D300/A700 are 12 MP.
« Last Edit: April 01, 2009, 09:42:48 AM by pegelli » Logged

pieter, aka pegelli
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« Reply #16 on: April 01, 2009, 10:17:50 AM »
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Quote from: pegelli
True, but for Nikon and Sony the difference is almost negligible. An APS-C size crop from the D3x and A900 is 11 MP while the D90/D300/A700 are 12 MP.

Yes. The Nikon APS-C is a slightly larger sensor than the Canon cropped format, and the D3X and A900 have a slightly greater pixel density than the 5D2. But the fact remains that the Canon 100-400 IS needs upgrading. The Nikon equivalent is no better.

A higher quality EF-S 100-400/F5.6 would still produce a 640mm FF equivalent, but could be lighter than the current FF 100-400/F5.6 and therefore more useful. I'm thinking here of the Canon EF-S 17-55/2.8. It's a sharper and lighter lens than the Canon EF 16-35/2.8. There must be a huge potential market for a high quality EF-S 100-400/F5.6 IS.
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BJL
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« Reply #17 on: April 01, 2009, 11:05:44 AM »
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As to the advantages of the smaller pixel size and thus higher sensor resolution in l/mm typically offered by smaller formats:
Quote from: pegelli
... for Nikon and Sony the difference is almost negligible. An APS-C size crop from the D3x and A900 is 11 MP while the D90/D300/A700 are 12 MP.
APS-C offers up to 15MP, which with the 1.6x crop of the 50D and 500D compares to 24.5MP/1.6^2= 9.6MP crop from the D3X or A900.
And the original example was Olympus, meaning Four Thirds. Cropping from 24x36mm (35mm) format to the 13x17.3mm frame of FourThirds retains about 26% of the pixels, so the highest resolution current 35mm format options would give about 6.3MP, vs the 10MP and 12MP currently available.

As to the ISO speed difference: we seem to be talking about using long, slowish lenses here, and when a smaller format gives the same pixel count on the subject while using a focal length that is shorter by a factor of 1.25x (50D and 500D vs A900 and D3X) or 1.4x (Olympus E-620 or E-30 or Panasonic G1 vs D3X or A900), that shorter lens can probably be brighter by half to one stop for about the same cost and weight, allowing a corresponding reduction in ISO speed, unless one has already bottomed out at minimum ISO speed.

The easiest comparison is the roughly 1.4x difference in l/mm resolution from Four Thirds to 35mm: the difference could be using basically the same lens, but with a 1.4x TC in 35mm, without in Four Thirds, with a one-stop lens brightness (minimum f-stop) advantage to not using the TC.


For occasional usage, an inexpensive Four Thirds body and lens mount adaptor to use telephoto lenses from another 35mm format SLR system on it could be a decent, low budget way to stretch telephoto reach. Manual focus and stop-down metering required though.
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Ray
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« Reply #18 on: April 01, 2009, 11:49:25 AM »
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In other words, BJL, to simplify your rather convoluted explanation (although my explanations might be equally convoluted to others, but not to me   ), an EF-S 100-400 could be F4 across the range and still no heavier than the current full frame EF-100-400/F4.5-F5.6. Right?
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BJL
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« Reply #19 on: April 01, 2009, 01:00:30 PM »
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Quote from: Ray
In other words, BJL, to simplify your rather convoluted explanation (although my explanations might be equally convoluted to others, but not to me   ), an EF-S 100-400 could be F4 across the range and still no heavier than the current full frame EF-100-400/F4.5-F5.6. Right?
No, not if one is talking true focal lengths.

What I mean is that for example a 400/5.6 and a 600/8 can be comparable in size and cost, and if used on cameras with pixel spacing differing in the same proportions of 2:3, both will give equal pixel count on the same subject, same framing. And for "equal shutter speed and equal pixel count after possible cropping to same FOV" one could be looking at, for example, the following imaginary lenses with equally large front elements, and so comparable cost and weight:
400mm, f/5.6, ISO 400 with the 4.3 micron pixels of an Olympus E-620 or E-30 or a Panasonic G1 or GH1
vs
500mm, f/7, ISO 500 with the 4.7 micron pixels of the Canon 50D and 500D
vs
550mm f/8, ISO 800 with the 5.95 micron pixels of a Nikon D3X or Sony A900,
vs
600mm f/8.4, ISO 900 with the 6.4 micron pixel spacing of a Canon 5DMkII or 1DsMkIII.
These are for exactly equal aperture diameter, as achieved with TC's for example. In practice the longer focal length options tend to be a bit heavier for equal aperture size. This is clear if the longer focal length is achieved by adding a TC!
« Last Edit: April 01, 2009, 02:04:11 PM by BJL » Logged
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