Poul Jensen

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

Comments

Total: 27, showing: 1 – 20
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In reply to:

DtEW: Honestly, sometimes Sigma does these "stunt" lenses just to do something unprecedented and tickle the imagination of the photography gearhead-set.

Sometimes they shine, sometimes they have minor caveats, and sometimes major ones.

It seems that with the amount of coma they can't seem to keep out of their ultra-fast UWAs, these lenses are actually more niche than the already-niche wide-field astro application that people keep hoping Sigma can work some magic with.

Do these seem to be reasonable UWA primes? Sure. Are they ultra-fast, faster than anything before? Sure. Can you run them wide-open? Sure, there's probably enough DoF at this short FL for reasonable usage. Can you run them wide-open at night at point light sources like everyone wants to? Well...

Honestly, I think people would have been more pleased had this just been a coma-free 14mm f/2-something at Sigma's Global Vision build quality.

So by "coma-free" you mean well-controlled coma. Yes, then you have options, and it turns out you already know some. How many options do you know for FF < 20mm < f/2.4? Would it be okay with you if a manufacturer finally met the demand for such lenses?

Link | Posted on Mar 2, 2017 at 03:14 UTC
In reply to:

DtEW: Honestly, sometimes Sigma does these "stunt" lenses just to do something unprecedented and tickle the imagination of the photography gearhead-set.

Sometimes they shine, sometimes they have minor caveats, and sometimes major ones.

It seems that with the amount of coma they can't seem to keep out of their ultra-fast UWAs, these lenses are actually more niche than the already-niche wide-field astro application that people keep hoping Sigma can work some magic with.

Do these seem to be reasonable UWA primes? Sure. Are they ultra-fast, faster than anything before? Sure. Can you run them wide-open? Sure, there's probably enough DoF at this short FL for reasonable usage. Can you run them wide-open at night at point light sources like everyone wants to? Well...

Honestly, I think people would have been more pleased had this just been a coma-free 14mm f/2-something at Sigma's Global Vision build quality.

Personally I wish lens reviews would include coma tests, but apparently coma isn't quite so important to others. Coma-free UWA f/2.x lenses do not exist, nor could Sigma produce one, but current UWA f/2.x lenses were already designed according to your priorities (IQ over speed). This lens was made to differ. Frankly, your post is like complaining that spoons were brought to market because you don't eat soup and think people would prefer a better fork.

Link | Posted on Mar 1, 2017 at 22:22 UTC
In reply to:

DtEW: Honestly, sometimes Sigma does these "stunt" lenses just to do something unprecedented and tickle the imagination of the photography gearhead-set.

Sometimes they shine, sometimes they have minor caveats, and sometimes major ones.

It seems that with the amount of coma they can't seem to keep out of their ultra-fast UWAs, these lenses are actually more niche than the already-niche wide-field astro application that people keep hoping Sigma can work some magic with.

Do these seem to be reasonable UWA primes? Sure. Are they ultra-fast, faster than anything before? Sure. Can you run them wide-open? Sure, there's probably enough DoF at this short FL for reasonable usage. Can you run them wide-open at night at point light sources like everyone wants to? Well...

Honestly, I think people would have been more pleased had this just been a coma-free 14mm f/2-something at Sigma's Global Vision build quality.

People with your priorities would have been more pleased, but you already have numerous choices for wide, high quality f/2-something lenses. I think most would disagree with your statement that it is "more niche than niche". There are plenty of good reasons for Sigma to produce this lens, including significant demand.

Link | Posted on Mar 1, 2017 at 16:04 UTC
In reply to:

keepreal: IMO Sigma would have done better to produce a smaller aperture version up to Art standards, but weighing in at no more than about 600 gm and costing half as much.

Unlike goactive, I sold off my D300 and bought a D610, keeping the full frame lenses I had bought while still using film. I also bought the AF-S Nikkor 20mm f/1.8G ED as I mostly like to shoot landscapes very wide. Had a suitable shorter focal length lens been available, I probably would have bough that instead. Perhaps the Irix 15mm would have done.

I will be keeping my Sigma 12-24mm F4.5-5.6 EX DG HSM Mk I. Testing it on the D610 last week I found that it was even across the frame and was already performing close to its optimum even at full aperture. Mine is quite sharp and has negligible distortion. On the D300 it was only so-so.

IIRC the fastest FF lens available < 20mm was f/2.4 until now. This is a pioneering product: A good quality lens with specs in a league of its own that a whole lot of photographers will be excited to buy because it will allow them to do things that simply wasn't possible before. The motivation for producing this lens (and not another lower aperture version to join a crowd) shouldn't be hard to see.

Link | Posted on Mar 1, 2017 at 14:42 UTC
In reply to:

JaredTarzan: What is the benefit to shooting DNG vs Canon's own raw format?

Not everybody has Adobe RAW/Lightroom/etc. or want to purchase it. Some folks appreciate open source and independence of proprietary software. Personally I'm very much in favor of universal formats over proprietary ones. Makes life easier (and cheaper too). I suspect DPR staff agrees. ;-)

Link | Posted on Jan 3, 2017 at 20:07 UTC
In reply to:

mmcfine: Competition is good but honestly I don't understand what makes this lens any better then current available options?
I don't understand why someone will spend money on a lens that keeps "ghosting, color aberration and flare under control". Most of these issue can be corrected in post and the rest are characteristics of a lens and scene which makes photography what it is.

It's the fastest 15mm FF lens available. Together with the focus lock and infinity click features, that makes it a very attractive option for night shooters.

Link | Posted on Sep 7, 2016 at 01:43 UTC
In reply to:

dash2k8: I don't mean to be picky, but the footage could probably have been taken with a regular Phantom 3 or 4. The only difference that the Matrice made was the heavier payload that allowed it to carry a better camera thus the lower noise. The flying part wasn't all that special.

@Moon: What dash2k8 didn't know about was the aurora, and you have good reason to be forgiving. Real-time aurora video is solidly out of range for a GoPro regardless of Kp. High Kp aurora is somewhat different in appearance and extends farther equatorward, but it isn't brighter.

Link | Posted on Aug 28, 2016 at 21:17 UTC
In reply to:

dash2k8: I don't mean to be picky, but the footage could probably have been taken with a regular Phantom 3 or 4. The only difference that the Matrice made was the heavier payload that allowed it to carry a better camera thus the lower noise. The flying part wasn't all that special.

Aurora footage is sensitive and difficult to work with. Between the noise reduction and the color correction you'd need to make the GoPro footage smooth/rich like A7s footage you will end up with some very artificial looking aurora. Add to that, due to the highly varying brightness and different colors appearing in the aurora your post work needs keyframing. Striking a balance throughout the video is time consuming. I'm probably somewhat of a snob when it comes to aurora footage because I'm so familiar with it, but I do believe that if you got GoPro and A7s footage to work with you'd end up agreeing there's a stark quality difference in the end result you can achieve (and time spent post processing to get there).

Link | Posted on Aug 28, 2016 at 06:18 UTC
In reply to:

babart: Nice video, I must admit, and I can only imagine how nice it must be to afford $8000 worth of camera equipment.

OK, call it envy, but just once I'd very much enjoy seeing photos/videos of some spectacular place or event made with equipment most of us could afford to own.

I share your frustration. In my opinion your work is fine, but doing good work isn't enough to be successful. You must reach an audience, and the competition for attention on the Internet is fierce. Successful marketing is a (rapidly evolving) science in itself. Unless your work is extremely good you must pay for exposure so people can find it - or you have to spend a lot of time/effort doing self-promotion around the web, which I also find rather distasteful.

I combined the best of my work from years of aurora photography in one art project, Beneath the Aurora (http://astralisproductions.com). I get fantastic feedback from those who see it, but very few will because I'm not willing to pour money/effort into marketing. And that makes me totally unfit for being an artist, regardless of skill. I'm 39 and only did photography 2004-2013. I can hardly imagine how frustrating the development must be for someone like you with a lifelong history of photography/arts.

Link | Posted on Aug 28, 2016 at 04:58 UTC
In reply to:

Mister J: Thanx for that. Next trip = Iceland.

If "they" refer to OZZO, it looks like they're based on Iceland and didn't have to.

Link | Posted on Aug 28, 2016 at 02:44 UTC
In reply to:

aramgrg: I wonder if anyone can share the settings used, in particular, ISO, f stop and SS. I just want to understand how dark is in there. Can this be done, for example with canon 6d and f2.8 lens?

Unfortunately the Canon 6D and an f/2.8 lens is far from being able to shoot aurora video of this quality - you'll likely have to do with exposure times of > 1 sec. But using a tripod instead of a drone you would still be able to capture excellent aurora footage - it would just be timelapse, not video.

Link | Posted on Aug 28, 2016 at 02:34 UTC
In reply to:

dash2k8: I don't mean to be picky, but the footage could probably have been taken with a regular Phantom 3 or 4. The only difference that the Matrice made was the heavier payload that allowed it to carry a better camera thus the lower noise. The flying part wasn't all that special.

The image quality in the GoPro footage is, in my opinion, much worse - both in terms of noise and washed out colors. What's worse, the GoPro footage is timelapse, not video like the drone footage. Based on my experience (I've shot lots and lots of aurora) I would guess each shot in the timelapse has an exposure time between 5 and 10 seconds, whereas the video footage is probably about 1/10 sec per exposure. That's a big difference. You can shoot aurora timelapse footage that looks as good as (or better than) real-time video - but not from a drone. It's possible a cheaper drone could do, I don't know about that. But you do need an A7s or A7s II and a fast prime to shoot aurora footage from a drone.

Link | Posted on Aug 28, 2016 at 02:21 UTC
In reply to:

babart: Nice video, I must admit, and I can only imagine how nice it must be to afford $8000 worth of camera equipment.

OK, call it envy, but just once I'd very much enjoy seeing photos/videos of some spectacular place or event made with equipment most of us could afford to own.

This footage is cutting-edge: I believe only the Sony A7s and A7s II could shoot aurora video of this quality, the Sigma 20mm f/1.4 used is less than a year old, and I would guess it takes a quite stable/expensive drone setup as well - plus, to shoot this you need to be at a place/time very few photographers are. For these reasons this footage is of a kind we haven't really seen before, and DPR obviously like to impress/inspire their readers with stuff like this.

That said, I feel your pain. It's somewhat distasteful how much the level of attention your work can get correlates with how much money you can afford to burn on gear/travel/setup, and the vast majority of photographers with ordinary equipment can hardly use something like this as inspiration for their own work.

Link | Posted on Aug 28, 2016 at 01:51 UTC
On article SpaceVR wants you to see the earth from space, in VR (12 comments in total)
In reply to:

matthiasbasler: Another strange product idea which does'nt really make sense to me.

Space images are cool, definitely. But most of the really cool ones (imho) highlight certain structures or processes (like algea bloom) in a certain area, or they are giant mosaics. Now, here we have a 4K camera for 180°. Depending on the satellite's orbit height this means only 4K are covered with the earth surface - or less. Don't think this is detailed enough to convince. Plus the image would probably look rather dull (due to atmosphere) just like the one shown above, unless digitally enhanced.

I wonder what the advantage of this is over Google Earth ... where I can view any part of the world whenever I want, and at any zoom level.

And last but not least, isn't Oculus Rift & Co. all about a 3D experience? You cannot deliver this with a conventional panorama camera, nor does it make sense without any foreground objects. So VR glasses seem overkill to me for this.

The purpose is to simulate what it's like (visually) to be in orbit as realistically as possible, so VR is important. The project was inspired by the Overview Effect reported by astronauts, and the idea is to give people access to a similar experience. Success hinges on two things: How realistic the VR setup feels, but also very much on your own ability to put your mind in the right place. For example, many who meditate would be thrilled to be able to put on VR glasses and chill with a real-time view from space.

As far as the VR quality goes, what I see on their website (samples with artifacts, lack of info) isn't promising - at least not for their initial camera setup. But considering the idea for the project was hatched only 18 months ago they've come remarkably far. If they can get some backing and keep developing the project I believe they'll end up with a highly successful product.

Link | Posted on Aug 12, 2016 at 20:31 UTC
On article SpaceVR wants you to see the earth from space, in VR (12 comments in total)

It's a fantastic idea. The samples on their website have fairly heavy artifacts though, which makes me concerned their initial implementation will leave a lot to be desired. The two cameras should use identical exposures to minimize artifacts, and space is an extremely contrasty place - meaning, the cameras will only be able to capture "part of the image" on the dayside, and what kind of footage the 4K sensors can produce on the nightside is a big unknown. Will be interesting to see initial results!

Link | Posted on Aug 12, 2016 at 01:35 UTC as 14th comment
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.

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.

Link | Posted on Aug 8, 2012 at 05:23 UTC as 60th comment | 6 replies
On article Preview: Canon PowerShot G1 X large sensor zoom compact (775 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.

Link | Posted on Apr 2, 2012 at 01:58 UTC
On article Just Posted: Canon PowerShot G1 X review (508 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.

Link | Posted on Apr 2, 2012 at 01:37 UTC
On article Just Posted: Canon PowerShot G1 X review (508 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.

Link | Posted on Mar 31, 2012 at 14:55 UTC as 41st comment | 2 replies
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