Poul Jensen

Poul Jensen

Lives in United States Fairbanks, AK, United States
Works as a Student
Joined on Mar 4, 2004

Comments

Total: 16, showing: 1 – 16
On Nikon D600 Hands-on Preview preview (718 comments in total)
In reply to:

peevee1: Strange, at high ISO (12800-25600) JPEG from D600 is significantly, by about a stop, worse than D800, and even worse than 5D3 by about half a stop. Something is wrong. At least in DXO testing high ISO of D600 and D800 was very close, with D600 even slightly leading.

Standard JPG processing is quite different between the two models. If you look at the RAW shots (which is what DXO analyzes) the D600 and 5D3 are similar in both noise and color while the JPGs presented here are noticeably different (Nikon = better color, Canon = lower noise). Nikon's default is NR off, couldn't find Canon's in exif (but it's definitely not off). It's unfortunate, what I'd really like to know is how JPGs compare with both cameras set to comparable noise suppression rather than their different defaults... :-/

Direct link | Posted on Sep 27, 2012 at 22:01 UTC
In reply to:

Poul Jensen: "A $2.5 billion project and their cameras have 2MP Kodak sensors?!?"

Yes, and you can thank your favorite camera manufacturer for the fact that their high-end camera technology cannot be used for science. Scientists need to know exactly what their equipment is doing, and the major commercial manufacturers won't tell - not even to NASA. And so scientists have to go to smaller manufacturers that are willing to cooperate and release full info.

It's a compelling idea that scientists should have the best equipment available. Unfortunately, commercial interests cannot be compromised.

Yes, Nikon cameras work in space and can take spectacular photos there. But those aren't used for scientific analysis.

Direct link | Posted on Aug 8, 2012 at 09:42 UTC

"A $2.5 billion project and their cameras have 2MP Kodak sensors?!?"

Yes, and you can thank your favorite camera manufacturer for the fact that their high-end camera technology cannot be used for science. Scientists need to know exactly what their equipment is doing, and the major commercial manufacturers won't tell - not even to NASA. And so scientists have to go to smaller manufacturers that are willing to cooperate and release full info.

It's a compelling idea that scientists should have the best equipment available. Unfortunately, commercial interests cannot be compromised.

Direct link | Posted on Aug 8, 2012 at 05:23 UTC as 59th comment | 6 replies
On Preview: Canon PowerShot G1X large sensor zoom compact news story (791 comments in total)
In reply to:

Danlo: The "silent" shutter is worth all the bulk.. Finally a quiet camera with large sensor for acceptable image quality.

Andy, could you please either correct the review to clarify that the G1 X has an electronic shutter and that the mechanical shutter is not used to control exposure - or, if you insist otherwise, explain why you are confident that the shutter in the lens controls exposure time. How would it operate to obtain a reasonably accurate 1/4000 sec exposure?

Edit: Sorry, just realized that this comment was on the old preview... unfortunately, the review still says the same.

Direct link | Posted on Apr 2, 2012 at 01:58 UTC
On Just Posted: Canon PowerShot G1 X review news story (525 comments in total)
In reply to:

Poul Jensen: Since I can't have confirmed otherwise I'll assume what appears most likely: That this camera has an electronic shutter like other Canon compacts. Inevitably that raises the question:

Why can't we have electronic shutters in DSLRs? Silent shooting, smaller/cheaper bodies that do not break as easily (I've only had cameras serviced/bricked due to failing shutters). The flagship argument has been that it requires extra circuitry that reduces the effective sensor area, hence reducing image quality which is an unacceptable compromise for a DSLR. For as far as it really had to be that way all this time, it doesn't anymore.

Silent shooting is an "exciting" new feature on the Nikon D4. But if you choose this (= electronic shutter) you only get 2MP resolution. This says a lot about manufacturers' willingness to let us use electronic shutters. It is going to be a painfully slow process with painful arguments (if any) from manufacturers.

Sigh. This is a waste of time, but here goes:

The reason compact cameras can do with a small leaf shutter in the lens rather than the big, clunky mechanism in DSLRs is that compacts have an electronic shutter. The leaf shutter is not involved in controlling the exposure time, but serves the simple purpose of being able to shut out light from the sensor. For CCDs this was necessary during readout to avoid smear (which I assume is what your blooming comment is referring to), and it is also necessary for long exposure noise reduction.

Direct link | Posted on Apr 2, 2012 at 01:37 UTC
On Just Posted: Canon PowerShot G1 X review news story (525 comments in total)

Since I can't have confirmed otherwise I'll assume what appears most likely: That this camera has an electronic shutter like other Canon compacts. Inevitably that raises the question:

Why can't we have electronic shutters in DSLRs? Silent shooting, smaller/cheaper bodies that do not break as easily (I've only had cameras serviced/bricked due to failing shutters). The flagship argument has been that it requires extra circuitry that reduces the effective sensor area, hence reducing image quality which is an unacceptable compromise for a DSLR. For as far as it really had to be that way all this time, it doesn't anymore.

Silent shooting is an "exciting" new feature on the Nikon D4. But if you choose this (= electronic shutter) you only get 2MP resolution. This says a lot about manufacturers' willingness to let us use electronic shutters. It is going to be a painfully slow process with painful arguments (if any) from manufacturers.

Direct link | Posted on Mar 31, 2012 at 14:55 UTC as 39th comment | 2 replies
On Just Posted: Canon PowerShot G1 X review news story (525 comments in total)

From "Features", bottom paragraph:
"It's clear that Canon has implemented much the same electronic 'first curtain shutter' in the G1 X as is used by its EOS SLRs in Live View mode (although the G1 X uses an in-lens, rather than focal plane shutter) ... The physical shutter is only used to end the exposure."

How do you know the implementation in the G1 X is any different from that in other Canon compacts - that is, the exposure is completely controlled by electronic shutter?

Find some super-slow motion footage of a DSLR shutter doing a very short exposure (e.g. google "shutter 2000fps"). Then consider how the G1 X could possibly produce a reasonably accurate 1/4000 sec exposure initiated by the sensor and ended by a mechanism in the lens.

Direct link | Posted on Mar 30, 2012 at 14:15 UTC as 79th comment | 1 reply

"The benefits for the consumer were top of mind when implementing this policy."
Really Nikon? Incidentally, establishing a complete monopoly not only on parts but now also on repair/service sounds like a decision made with Nikon being top of mind. There's a reason why there is a market for independent servicing.

"Dentry points out that independent service shops can apply to join the 20 centers authorized to repair its DSLRs in the US"
How nice of you to think of them. They can buy for $160K equipment from you and sign a contract that allows you to kick them out at any time, problem solved.

Nikon, you deserve all the heat you get.

Direct link | Posted on Mar 13, 2012 at 00:53 UTC as 160th comment
In reply to:

Dominic G Smith: How many people (Poul Jensen below), earning $2k per year can buy a D700, plus the lens and flashguns needed. I started with 2 bodies,2 lenses and 1 flash. Cost $1,000. The female photographerwho replied to the initial Craiglist post, earns about $50 per hour before tax etc. Low for a professional. Some photographers advertise prices that will lose them money. Most work 12-14 hour days including weekends. Spread over the cost of the business, you can earn the same per hour working at a supermarket checkout ($10/hour) approx. I wonder how much Bridezilla was willing to pay and what she expected to get for it? Occasionally when couples do query the price, I tell them, after the cost of the album(s), they are paying form my time, experience and abilities as a wedding photogarpher. That is basically what we are selling - and although this is what this bride seemed to be looking for, she did not seem to want her photographer to make a profit or a living

http://www.bridalimage.co.uk

You'll have to do some pretty manipulative math to make a $10/hr job as profitable as $2.5K wedding shoots, but that aside...

The problem is the level of profit and standard of living that you demand. You're extremely privileged to be able to make a living doing photography, and you owe thanks to the guy at the checkout not to mention the people risking their lives in Chinese coal mines for the hard work they're doing that allows you to spend your time doing photography. I'm pretty sure you don't envy them their jobs, yet if they were to have an income comparable to yours you'd feel the world was unjust.

Direct link | Posted on Jan 27, 2012 at 17:49 UTC

$50K/yr for 20 jobs of ~30 hours, and she complains that she has to take on other jobs to make ends meet? Even worse, somebody at DPReview posted this as "an excellent response"?

Some people need to come down to Earth. The world median income is about $2K/yr, and the "median job" is not somehting as luxurious as taking/processing photos. Please take a moment to think about just how privileged you are.

Yes, $3K for wedding photography is definitely too much.

Direct link | Posted on Jan 27, 2012 at 13:20 UTC as 193rd comment | 1 reply
On Preview:canong1x (1044 comments in total)
In reply to:

Poul Jensen: Question: Does the mechanical shutter really end the exposure as the preview says? AFAIK other Canon compacts just have a flap to protect the sensor from constant exposure. If it is actually used to end the exposure, then it needs to be of a complex design to end the exposure in sync with how the electronic shutter started it (and it ought to sit at the sensor, not in the lens?). This would be bad news because DSLR-style shutters break. Canon compacts are particularly good for timelapse, and the lack of a short-lived mechanical shutter is one of the reasons.

@ Andy: Thanks for your reply, much appreciated. Are you sure the exposure is not terminated by en electronic shutter before the mechanical shutter in the lens is closed? Looking at how a mechanical SLR-style shutter operates for high shutter speeds (e.g. google "shutter 2000fps"), how would the G1 X manage to make an accurate 1/4000 exposure if it is started electronically at the sensor, but ended by a mechanical shutter in the lens? The opening/closing has to be highly in sync in order for all of the sensor to be exposed equally, and I'm not sure this is even possible if the mechanical shutter is not right in front of the sensor. The farther away from the sensor it is, the more gradual the transition from exposure to darkness is for an individual pixel. Does the mechanical shutter look like a simple flap as in other Canon compacts?

Posted on Jan 17, 2012 at 08:11 UTC
On Preview:canong1x (1044 comments in total)
In reply to:

Poul Jensen: Question: Does the mechanical shutter really end the exposure as the preview says? AFAIK other Canon compacts just have a flap to protect the sensor from constant exposure. If it is actually used to end the exposure, then it needs to be of a complex design to end the exposure in sync with how the electronic shutter started it (and it ought to sit at the sensor, not in the lens?). This would be bad news because DSLR-style shutters break. Canon compacts are particularly good for timelapse, and the lack of a short-lived mechanical shutter is one of the reasons.

That the shutter sits in the lens is what makes me think that its implementation doesn't "inherit" anything from DSLRs - it's how it's always been implemented in Canon compacts which means the mechanical shutter is not used to end the exposure. I would like to see this corrected, or be corrected myself if I am wrong about this.

Shutter lifetime is not an issue for normal photography. I shoot timelapse almost exclusively and have gone through 5 shutters so far. It adds a price tag to each timelapse I shoot just in terms of the cost of shutter replacements.

Posted on Jan 15, 2012 at 03:00 UTC
On Preview:canong1x (1044 comments in total)

Question: Does the mechanical shutter really end the exposure as the preview says? AFAIK other Canon compacts just have a flap to protect the sensor from constant exposure. If it is actually used to end the exposure, then it needs to be of a complex design to end the exposure in sync with how the electronic shutter started it (and it ought to sit at the sensor, not in the lens?). This would be bad news because DSLR-style shutters break. Canon compacts are particularly good for timelapse, and the lack of a short-lived mechanical shutter is one of the reasons.

Posted on Jan 14, 2012 at 02:02 UTC as 222nd comment | 5 replies
In reply to:

Cy Cheze: The "skinny": To see auroras, one must go to the Arctic regions in midwinter darkness, have a clear sky on a frigid night, go 30-40 miles away from any city lights, and preferrably pick a year that fits one of the solar cycles (every 22, 87, or 210 years). To photograph them, you better keep the batteries warm and not freeze your own fingers or nose, either.

I'd truly wonder how you could photograph the auroras with a full moon in the frame. Do montage and layering help? I presume that most of the shots involve some enhancement relative to what the naked eye actually sees. This also happens with astronomical or microsopic imaging, but the boundary between nature photography and painting may be a dim swath of of green.

Where are the red, purple, or violet aurorae? The samples are all emerald. No multi-color "shows" on a given night? Is it necessary to pick another season or year?

Indeed, most of the time the naked eye does not see the colors that the camera does - it needs a certain intensity of light to be able to identify colors. So most of the aurora in these shots would actually look pale white with a hint of green, but when the aurora gets really bright (and especially if it's overhead) you do get to see the colors.

Also, the colors actually do depend on season and time of night.

Magenta lower borders occur mostly in evening and around midnight. They are hard to capture because they come in brief and bright bursts, and you'll have to dial down the exposure quickly and just right not to overexpose and wash out the magenta.

Often you also get a different color at the top of curtains - red or blue. If the sun is shining at the altitude of the curtain tops (close to sunset/sunrise) it will be blue. If it's solidly in Earth's shadow it will be red, and during transition you can get a beautiful mix of blue and red.

Direct link | Posted on Oct 13, 2011 at 20:21 UTC
In reply to:

Ben Hattenbach: Hi Folks. Thanks very much for all the positive feedback. It will help keep me warm on my next photoshoot. Poul, with respect to your comment on the science, the scientific portion of the article (Section 1) was provided by a Ph.D. astrophysicist who, as a professor and researcher, has studied aurorae not only on earth but on other planets. It was intended to be understandable by lay people, not a comprehensive dissertation; nonetheless, I believe (and sure hope) it is entierly accurate from a scientific perspective.

You did well then, but I would have some arguments with the astrophysicist (Henry Throop I take it) who authored your Section 1 and 2. That discussion doesn't belong here, but I would like to point out that when you are watching the aurora, you are not seeing "focused solar wind" or turbulence created by the solar wind blowing by the magnetosphere as you might think from this article. You are watching processes internal to Earth's magnetosphere (though, ultimately the energy fueling these processes does come from the solar wind).

Direct link | Posted on Oct 13, 2011 at 09:04 UTC

While there is plenty of good info/advice for aspiring aurora photographers, the author is not on top of the science behind the aurora and would have done well to have the article revised by someone who is. But then, while the article wouldn't pass a scientific review, the details that are off are practically irrelevant since this is a photography and not a science forum...

Direct link | Posted on Oct 12, 2011 at 23:02 UTC as 53rd comment
Total: 16, showing: 1 – 16