Henrik Herranen

Lives in Finland Tampere, Finland
Works as a Digital Signal Processing Software Engineer, MSc
Joined on Oct 6, 2005
About me:

Plan: To baldly shoot what everyone has shot before.

Comments

Total: 230, showing: 1 – 20
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On article Accusations fly over Fukushima photos (88 comments in total)
In reply to:

Noosaboy: I worked in the nuclear energy industry and took many photos with film. If the radiation was too high it over exposed the film (whether you pressed the shutter button or not). In fact I always carried a piece of 35mm film in a red plastic badge which was sent off every month to indicate the amount of radiation I had received. Does anyone know what the effect would be on a digital sensor? None of Keow's photos seemed affected!

Hans van de Riet: well, I'm afraid you are wrong, both in fact and reasoning.
1) Alpha particles are stopped by pretty much anything, including a sheet of paper. That's why even the thinnest protective suit over the skin / protecting eyes is useful.
2) Beta particles can be stopped by a few millimeters of aluminium. A metal camera body would be sufficient for that.
3) Only neutron radiation that needs lead for protection. Nasty stuff.

I never claimed that no radioactive radiation would the sensor. I just said it doesn't have much time to affect your images. The relevant radiation exposure time is around 1/100s for exactly the reasons I told in my previous message: the sensor is electronically cleared, then the shutter clicks, and finally the result is read. With short exposure times this takes at most a hundredth of a second. Stray radiation between exposures won't cause anything unless at extreme levels that would kill both your camera and you.

Link | Posted on Jul 25, 2016 at 19:36 UTC
On article Getting up close: Canon EF-M 28mm macro hands-on review (103 comments in total)

Page 2 says: "Canon is able to achieve a 1:1.2 reproduction ratio"

That should read 1.2, not 1:1.2.

Link | Posted on Jul 22, 2016 at 05:43 UTC as 17th comment | 1 reply
On article Accusations fly over Fukushima photos (88 comments in total)
In reply to:

Noosaboy: I worked in the nuclear energy industry and took many photos with film. If the radiation was too high it over exposed the film (whether you pressed the shutter button or not). In fact I always carried a piece of 35mm film in a red plastic badge which was sent off every month to indicate the amount of radiation I had received. Does anyone know what the effect would be on a digital sensor? None of Keow's photos seemed affected!

The film is constantly being "exposed" by the radioactive radiation until developed, so if you hold your film roll in a radioactive area for a month, it gets the radioactive exposure of the whole 30 days (minus the protection given by your camera / film roll / wherever the film is encapsulated to protect it against light).

With digital sensors it is different. The sensor is cleared electronically just before the exposure, then the shutter operates, and finally the result is read from the sensor. So, if you use a sufficiently short exposure time, the time radioactive radiation has time to act on your image is in the order of perhaps 1/100 of a second.

All this means that for it to have any effect on your digital images, radioactivity has to be on a fatal level. At those levels, radioactivity may start to damage ROM/RAM memory cells and other vital camera electronics, so it may render the whole camera inoperable - permanently. Of course, as you're dying, it's the least of your issues.

Link | Posted on Jul 21, 2016 at 07:52 UTC
On article Accusations fly over Fukushima photos (88 comments in total)
In reply to:

Sean65: The photos were a joke. They were not about Fukushima but all about the idiot who decided he would be the subject matter of each image. Strolling around dressed like a chav wearing a respirator, which would have done absolutely nothing to protect against exposure of radio active waste.

Is this the future of photojournalism, the me generation unable to resist the banal temptation to appear in all their own photos.

The Davinator is correct: a proper mask does protect against radiation. Here's why.

Radiation in itself is pretty harmless even at quite large doses (e.g. you get 50-100 times the normal background radiation when at in-flight heights because you've left most of the atmosphere below you, yet it's ok). Contamination, however, is a different thing because that way you may ingest low-radiation particles that may stay and continue radiating inside you for the rest of your days, so the risk to your health accumulates.

Having said that, it may still be that the mask was just for show. I've been to the Chernobyl area (legally), and nobody used masks. There really was no reason with the kinds of radiation levels they had there. The only precautions I did was I didn't lie on the ground even when a photo would have gotten better perspective by doing it, and I didn't eat anything in the exclusion zone. I did buy a beer in Chernobyl's only open shop, though.

Link | Posted on Jul 20, 2016 at 05:48 UTC
On article Comparison Review: Sony FE 50mm F1.4 ZA vs 55mm F1.8 ZA (228 comments in total)
In reply to:

new boyz: I think the focus planes were not exactly the same(f1.7 vs f1.8). 50mm is sharper for nearer objects, while 55mm sharper halfway to infinity. And for the 50mm, the left half is sharper than the right side.. so maybe decentering or something.

Also while comparing at f2, I can clearly see an airplane(Air Force One?) on 50mm sample... the 55mm missed it. :)

Oh, I just wrote a similar message... You beat me by less than a minute. :-)

Link | Posted on Jul 20, 2016 at 05:39 UTC
On article Comparison Review: Sony FE 50mm F1.4 ZA vs 55mm F1.8 ZA (228 comments in total)

Hey, have you looked at the BOTTOM left and right at the picture? There the 50/1.4 clearly outresolves the 50/1.8, while on the TOP left and right the 50/1.8 wins as you stated.

Could it just be that the two lenses are focussed ever-so-slightly differently so that the bottom which consists of closer subjects (compare the chimneys) could be just a tiny bit more in focus on the 50/1.4 while the objects further away at the top would favour the 50/1.8's focusing? If this is correct, then there is no inconsistency with Roger's results.

Link | Posted on Jul 20, 2016 at 05:38 UTC as 38th comment | 1 reply
In reply to:

Kuvasauna: The radiation level on most of the exclusion zone isn’t really very high. There are many populated areas where natural background radiation is higher that the level Japanese officials used as threshold for evacuation. Just visiting the area would not be risky at all if one does not go near the actual power plant.

And to add:
"Natural background radiation is harmful, including radiation from the sun" doesn't make any sense as a sentence as solar radiation is _not_ a part of background radiation.

Fortunately, it is easy to Google what the term means:
https://en.wikipedia.org/wiki/Background_radiation

Link | Posted on Jul 14, 2016 at 16:01 UTC
In reply to:

Kuvasauna: The radiation level on most of the exclusion zone isn’t really very high. There are many populated areas where natural background radiation is higher that the level Japanese officials used as threshold for evacuation. Just visiting the area would not be risky at all if one does not go near the actual power plant.

bobbarber:
You seem to have a seriously flawed understanding of how radiation works. Solar radiation is a completely different thing from radiation from radioactivity, natural or human-made. Background radioactive radiation is way less dangerous than that of excessive sunbathing, they are not even in the same ballpark. Even if you multiply a typical background radiation level by 100 (e.g. from 0.08 µsV/h (microsieverts per hour) to 10µsV/h), you'd still be safer than if you smoked a few cigarettes a month (yes, a month, not a day).

When I visited Chernobyl and Pripyat in 2008, I got less cumulative radiactive radiation during my 9-hour stay there than I got from the 2-hour flight from Helsinki to Kyiv. Surely there's nothing to worry about such levels. Then again, I must point out that there _are_ hot spots there that are best left alone, and I didn't go specifically looking for them.

Anyway, I recommend you learn a bit of radioactive radiation before spouting nonsense.

Link | Posted on Jul 14, 2016 at 15:58 UTC
On article Medium-format mirrorless: Hasselblad unveils X1D (1190 comments in total)
In reply to:

Marksphoto: that's a thin body, I had to wonder... This isn't a true medium format camera, make no mistake, my 5dmk2 will make the same image quality and I don't know whose images will look better at a pixel peeping level...

True medium format is 60mm x 45mm, I think Hassy should be 60mm x 60mm so they keep true to their marketing values. So what do we have instead.... a 44x33mm sensor; how does that compare in size to 36x24mm that most of us already have?

So I made a sensor comparison chart here: https://photos.google.com/search/_tra_/photo/AF1QipNF1V4qJeB95tYIwYlkryp6nNMFXT2BU9isJgCq

Judging that this sensor is not that much bigger than the 35mm full frame sensor we could really get away with the same or better results by just adding any sigma art lens with a fast apperture of 1.4 and call it a day!

Only one slight problem, mate...

"Sign in with your Google Account"

Link | Posted on Jun 22, 2016 at 20:37 UTC
In reply to:

nimrod1212: "while they only draw 100 watts they deliver dimmable output of more than 400 watts" You can't get more energy out than you put in. I can only assume this is meant to be interpreted as "...more than 400 watts of tungsten-equivalent luminance.", which is somewhat vague in any case, depending on the particular incandescent bulb. I agree with TwoMetreBill. Not all manufacturers quote output in lumens, but they really should abide by such a universal standard as these newer technologies develop.

Amen to that.

Using language like that is misleading in the least. After all, efficiency of tungsten lamps vary greatly: a 5 watt lamp efficiency is typically 5 lumens/watt (25 lumens total) while a 100 watt lamp can be upto 18 lumens/watt (1800 lumens total). So, even a tungsten lamp can have close to four times the efficiency of another tungsten lamp!

I suspect they're using using weasel speak instead of facts because the light power of their lamps (as measured in lumens) isn't very good. If it was, they'd be giving us the number.

Link | Posted on Jun 10, 2016 at 05:08 UTC
On article Pentax K-1 Pixel Shift Resolution: Updated Field Test (210 comments in total)
In reply to:

VisualFX: Pixel shift is just a mid-technology kludge, until higher resolutions image sensors become more affordable and mainstream. I would never rely on it, even for supposedly "static" scenes, since there is always some amount of movement in landscape scenes. What is needed is more dense sensors.

Left eye: I'm afraid I have to disagree about the inevitability of Bayer sensor moire artifacts.

When we, in time, have sensors that have such an amount of pixels that images always are diffraction limited, moire will be a thing from the past. For Full Frame, the limit seems to be around 100 megapixels, and today we are already at half of that. Give it a few more years, and moire will be a thing of the past with Bayer sensors.

Don't get me wrong. Now is now, and I fully agree that Pixel Shift is a wonderful technology that I wish was at my disposal today (I shoot an almost 10 years old Canon FF camera). Still, we all know that Pixel Shift is feasible only with static scenes. When, in a few years, 100 MP or so FF sensor are available, that will solve the problem once and for all. Meanwhile, and potentially for a good number of years to come, Pentax will give its users the best APS-C quality possible, beating most if not all FF cameras when the scenery remains static enough!

Link | Posted on Jun 4, 2016 at 16:26 UTC
In reply to:

dansclic: Who cares about this ? People paying more than 6000 dollars are not buying sigma lenses I guess ? I wouldn't anyway. Professional photographers do not want to create problems for themselves, So better stick to genuine lenses that will never cause any problem.

... or a Canon 50mm lens that has even nearly the image quality of Sigma's 50/1.4 Art.

Link | Posted on Jun 3, 2016 at 06:03 UTC
In reply to:

qwertyasdf: 2x TC on 100-400mm f4.5-5.6 gives 800mm @ f11.2, if this qualifies as bringing 1219 to a system, I might as well stack five 2x TCs on a Canon 1200mm and and bring 8,246,337,208,320mm to the EF system, on a crop body.

qwerty: for that you'd need thirty-two stacked 2x TCs (1200*2^32*1.6 ~= 8.24*10^12).

With five stacked 2x TCs you'd end up with 1200mm*2^5 = 38400mm f/180, which would be equivalent to 61440mm when used on a 1.6x crop body.

Warning: if really pixel-peeping, you might notice some slight diffraction softening.

Link | Posted on May 19, 2016 at 07:13 UTC
In reply to:

The Squire: Only 1080p? At least it's "spectacular 1080p"!

BartET:
I'll take your bet. As we live in different countries (I assume), let's choose a common subject: The Moon. The one who gets the better picture without any extra optics, wins.

So, how much was your monthly salary and how are you going to pay? Or are you just trolling?

Link | Posted on May 11, 2016 at 14:23 UTC
In reply to:

tkbslc: f6.6? I guess it's good for outdoors in the afternoon.

phototransformations: you are of course absolutely right. But take into account that what you are answering to must be a feeble attempt at trolling. Nobody could be so clueless.

Link | Posted on May 11, 2016 at 14:14 UTC
In reply to:

tkbslc: f6.6? I guess it's good for outdoors in the afternoon.

f/6.6 on a crop factor 5.6 system will have similar diffraction as a Full Frame lens stopped down to f/37, so regardless of whether the optics are good or not, image quality will by necessity be limited. Then again, what choice is there if you need a superzoom in such a small form factor?

Link | Posted on May 11, 2016 at 05:50 UTC

DPR writes:
"It also brings a modest increase in resolution because you're sampling luminance (green) information at every pixel position and not effectively blurring it by borrowing it from surrounding pixels."

Luminance is _not_ green. Green is green. Luminance is a weighted sum of red, green, and blue. Remove the incorrect and confusing "(green)" qualifier and you're golden.

Btw, if you want to compare high-resolution images, why is the Nikon D810 in the default resolution comparison instead of the higher resolution Canon 5DS R?

Link | Posted on May 5, 2016 at 22:04 UTC as 126th comment | 1 reply
In reply to:

Henrik Herranen: Assessing skintones by taking a photo of a photo is a bit like a broken pencil - pointless.

The spectral features of a 4-colour print (under artificial light) are vastly different from the spectral densities of real skin. Hence, the results may be quite different.

Real-world example:
- If I take a photo of hot coals with my Canon S90 with white balance set to Incandescent, IR leakage will make the coals appear purple, even close to blue.
- If I take the same photo with my Canon 5D Mark II, the coals are red as they should because this camera has a proper IR filter.
- If I print the 5D2 photo on paper, take a photo of this photo with my S90, then upload it to the web for all to see, it will give a completely incorrect impression of the S90's colour capabilities.

Fair enough, Rishi.

By the way, speaking of colour of light...

Wouldn't it be _really_ interesting if there was a way to take a photo of a continuous spectrum, starting from deep UV through visible light right into deep IR territory? That would show some significant colour production differences, particularly with small sensor cameras, including camera phones. My experience is that some of them have proper IR filters, but most of them don't, which affects e.g. skin tones under incandescent light.

So, how about getting a continuous-spectrum light source plus an appropriately big prism, then adding the output of such a system to the standard test image suite? That way you'd get the separate frequency responses of the R, B and B filter elements: how much do they bleed to each other, and what colours are difficult to represent accurately. Might be pretty interesting...

Link | Posted on May 4, 2016 at 21:37 UTC

Assessing skintones by taking a photo of a photo is a bit like a broken pencil - pointless.

The spectral features of a 4-colour print (under artificial light) are vastly different from the spectral densities of real skin. Hence, the results may be quite different.

Real-world example:
- If I take a photo of hot coals with my Canon S90 with white balance set to Incandescent, IR leakage will make the coals appear purple, even close to blue.
- If I take the same photo with my Canon 5D Mark II, the coals are red as they should because this camera has a proper IR filter.
- If I print the 5D2 photo on paper, take a photo of this photo with my S90, then upload it to the web for all to see, it will give a completely incorrect impression of the S90's colour capabilities.

Link | Posted on May 4, 2016 at 16:45 UTC as 106th comment | 4 replies
On article The Canon that can: Canon EOS 80D Review (691 comments in total)
In reply to:

Zerixos: Its nice to see that they stept-up there game. I think it once-again adds something to there line up since the 50D (the 60D and 70D where more like a 50Ds and 50DII in my opinion) and make it a great allround camera. I'm just a little sad not to support 4K video. Anyone saying you don't need 4K is right, for now. But knowing you want it in the (near) future is gonna make this a quick aging camera.

1080p that keeps consistently in focus without hunting or breathing looks better than 4k that is out of focus or constantly jumping and pumping.

So yeah, it's not 4k, but it's consistently good 1080p.

Link | Posted on Apr 28, 2016 at 07:35 UTC
Total: 230, showing: 1 – 20
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