dmozzherin

A friend of mine sent me this link about a prototype digital camera

from Stanford University. This camera allows to take pictures with

wide open lens first and later decide on DOF or even refocus the

image. Does anybody have comments about this development? Sounds like

an extremely cool idea!

 

http://graphics.stanford.edu/papers/lfcamera/

>>> Or your 500mm is less sharp than average. As much as I like 100-400

 

>>>this lens is tad less sharp than 100 and much less than 500 f4. I

 

>>>always compare 100% crop:

 

Mark, I shot a target at different conditions with 500mm, 100-400, and 400DO

full thread is here:

http://www.photo.net/bboard/q-and-a-fetch-msg?msg_id=00Cp3e

 

One of the examples from the thread (all are 100% crops)--

http://www.photo.net/bboard/big-image?bboard_upload_id=24581684

I own 100-400mm and use it with 20D. Contrary to many reviews I find this lens quite sharp! I use it with TC too sometimes.

Example of this lens with 1.4tc is here:

 

http://www.photo.net/photo/3480518

 

Without TC:

 

http://www.photo.net/photo/3925431

 

I also own 500mm f4 and honestly starting from f/7.1 their sharpness

is the same to my eye (and I ran a side by side comparison of this lens with another 500 f/4 which showed the same). It could be my 100-400mm lens happened to be better than average, I don't know. It was produced in 2005.

Peter, from what I read not all 400DO are created equal. Probably you got a better one. What is the date code on your lens? This code is located at the end which connects to the camera. For example US0821 means that the lens is produced in Utsonomiya in august 2004. U - code for the factory, S code for the year (2004) 08 - code for the month.

Yakim, all the 100% crops are already posted at the end of this thread:

 

http://www.photo.net/bboard/q-and-a-fetch-msg?msg_id=00CXcM

 

 

All of them are taken on tripod with MLU.

>>In the pictures you posted in the "old" thread the 500 seems to go soft @ f/8 and then, sharp again @ f/11, in the low light samples. This doesn't happen in the flash lit samples. Also, it is not characteristic of the lens, as far as I know (I don't own one but, have use it quite a few times). Did you manually focus and how fast was the shutter for those low light tests?

 

Low light focus was automatic, shutter speed varied from 1/2.5 to 30s depending on the aperture. All pictures were done with mirror locked up. I did not have time to repeat test (I've got 500mm only for couple of hours) and it is possible that some shots are soft because of problems with focusing or camera shake. However they were good enough for me to decide if I should keep 400 DO or go for 500mm.

// Either you got a great 100-400 or a not so great 500!

 

I borrowed 500mm from someone and it seems his lens is as sharp as anybodys else I know. I wonder if 100-400mm lenses produced in 2005 are somehow improved.

 

For example here is a 100% scale fragment of this shot:

 

http://www.photo.net/photo/3406566

Recently I bought 400mm DO IS USM lens hoping to use it for hendheld

bird photography. Few weeks ago I posted a question asking a

first-hand opinions about this lens. Not many people seem to have it

and I decided to publish results of my tests. You can find them at the

older thread:

 

 

http://www.photo.net/bboard/q-and-a-fetch-msg?msg_id=00CXcM

 

I compared this lens with 100-400mm L at 400mm and 500mm L f/4

 

My conclusions:

 

1. 400mm DO (produced in 2004) is quite soft at f/4

2. 100-400mm L (produced in 2005) is (amazilnly enough) as good as

500mm L if there is enough light

3. 500mm (produced in 2005) was a definite champion

4. For almost all purposes my 100-400 was a bit better than 400mm DO

so I decided to send the later one back and get 500mm instead.

 

 

Please let me know what do you think about this results.

I loved how easy it is to use this lens for fird photography. It is light, compact, easy to handheld, IS works very well. It it would only be sharper! I hope that DO technology will get better with time and we will see excellent 400, 500, 600, 800mm DO lenses in the future. For now though 400 DO is not what I can justify to keep.

 

BTW I am pleasently surprised how well 100-400 stands against 500mm.

You can tell that it is only shots of the resolution charts, but I have examples of real life pictures which to my eye are not any worse than 500mm L shots.<div></div>

Same tests as above but with 1.4x TC attached. Shutter speed was 1/250s,

apertures from f/5.6 to f/32

 

Conclusion:

Again, 500mm (700mm in this case) was significantly better than 400DO and 100-400mm performed great with f/11 and higher.<div></div>

Same conditions but with 2 flash lighting the chart. Exposure was 1/250s

Aperture from f/4 to f/32

 

Conclusion: 500mm was the best (strangely softe at f/4 by some reason, could be an experiment mistake), 400mm DO was again not very sharp wide open, 100-400mm was again comparable with 500mm with f/8 and higher. All lenses start to get soft at f/22 and f/32.<div></div>

100-400mm L is produced in 2005, 400mm DO is produced in 2004, 500mm L is produced in 2004

 

First test was done in low light room with exposures from 1/2.5s to 30s

and apertures from f/4 to f/16

 

All resulting raw files were linearized and normalized according to

Macbeth Colorchecker greyscale known values for Adobe RGB space

 

My conclusion: 500mm is a champion, 100-400mm is comparable with 500mm after f/8, 400mm is soft at f/4 and still a bit soft at f/5.6<div></div>

Short version: I sent the lens back and I am getting 500mm f/4. I found that it is pretty soft wide open. It becomes reasonably sharp at f/5.6. However I alreay have 5.6 400mm lens which is cheaper and lighter.

 

I am posting results of the tests here.<div></div>

>I find most pleasure in bird photography when I am able to interact with birds in some way -- to wade together with them in water, befriend them in a wild forest, crawl to them etc.

 

>>That's certainly a very valid point of view, but it's also the case that the closer you get to a bird, the more you're likely to be disturbing it or interfering with behavior, etc.

 

You are right Mark, especially if you use your art as a scientific tool as well. I take your point seriously and I try my very best to decide if my presence is a threat to an animal. I don't think you can see signs of fear or discomfort from animals I photograph. If you do, please let me know immediately!

 

I have to add though that --

400mm * 1.4x * 1.6 of a digital camera is not that short :-)

Thanks a lot for all the input! I find most pleasure in bird photography when I am able to interact with birds in some way -- to wade together with them in water, befriend them in a wild forest, crawl to them etc. This is my main reason of wanting a short and relatively light lens. I ordered 400mm DO. I'll post here my impressions.

I am considering to buy either 500mm f/4L or 400mm f/4 DO lenses for

(mostly) handheld bird photography. I know that 500mm is of excellent

quality, but the weight and the size of 400mm f/4 are so attractive.

 

I've read many bad reviews about 400mm f/4 released in 2001-2002,

could not find anything definite about 2003 but quite a few people

wrote that after 2003 sharpness and contrast of 400mm f/4 lens

increased significantly and can rival 300 f/2.8 with 1.4x teleconvertor.

 

If anyone has firsthand experience with 400mm f/4 DO manufactured

after 2003 alone and with canon's 1.4x and 2x teleconvertors please

let me know!

 

Thanks in advance

Thanks for your input! Bob, thanks, at least now I know it is normal and I should not try to exchange my lens.

It is the most obvious at a very contrasty highlights, but on this fragment it is even possible to see chromatic abberration (a reddish hue) on the wing of the tern.

I recently bought 100-400mm IS USM lens from Canon. To my surprise I

discovered quite strong chromatic abberration when I used this lens.

Can you tell me if it is normal, or I just got a bad specimen?<div></div>

Hendrik and David, thanks for your insights!

Shun, thanks for sharing your ideas. I still feel I want VR more than additional 20% of magnification. that 500mm would give me. I guess I'll settle with 200-400mm not until something longer with VR will appear.

 

D2X is a great body for sure, I wish I'd have it too. With a sharp lens it practically gives you another x1.5 advantage over D70 or D100 because of same size of the chip and 2x more pixels (besides focus speed, frames rate and other great goodies).

Mark, thanks for the compliment! Photo.net is a very good school for me. I am learning a lot here. I like your work too! BTW you might be interested in my last triplet of a Puerto Rican endemic, the cutest bird I've seen with my own eyes:)

 

I think you are right that for actual lens lengths anything longer than 800mm tripod is required, but it is not so for VR equipped <600mm

lengths.

 

I do not use tripod for my 80-400mm birds pictures. And I think it gives me some advantage. It is faster for me to make a shot as soon as I see a bird, and it allows greater flexibility of positioning camera in any imaginable position in a short time. I want to continue refining this technique and for that 200-400mm/4 VR is probably better than 500mm/4 (if I will be able to cope with its weight of course:-).

Mark, thanks for the suggestion. I do consider 500/4 too. I am only afraid that I will not be able to make good pictures handheld with this lens (unless of course if I shoot something in the sky on sunny day).

Greg and Lucein, thanks for the information! I wonder how well D70's autofocus works with 1.7x teleconvertor on 200-400.

Thanks Umit and Chan. Umit, you are right, and I was wrong -- VR stays with teleconvertor. You are right again about optical quality. It seems that it makes 200-400mm a better choice with two major drawbacks in price of the lens and weight. Chan, thanks for weight input. 200-400 is about 2x heavier than 80-400mm. With 80-400mm VR I can focus on a bird and slowly approach it making shots from time to time for up to an hour and my arms don't feel tired. I imagine it is much harder with 200-400mm. May be use of a monopod in such cases will help. Or I should go to the gym more often, but to increase your strength 2x is a very challenging task ;-)