JensR

Lives in United Kingdom Bath, United Kingdom
Works as a Mechanical Engineer
Joined on Nov 23, 2003
About me:

Hi,

thanks for stopping by!
If you want to see what I'm up to, send me a message :)

My 'plan':
Talk Pentax into a digital Electro-Spotmatic! (This needs some work...)

-------------

Older Signatures:

'LBA knows no bounds, and seeks no justification...' (Jim King, 2005)
http://www.jr-worldwi.de/photo/index.html - Photography, Tech and Geek stuff :}

'Why is everyone answering rhetorical questions?' (Me, 2005)

'Well, 'Zooming with your feet' is usually a stupid thing as zoom rings are designed for hands.' (Me, 2006)

'I only trust those photos I have faked myself.' (Me, 2007)
http://www.jensroesner.de/

--=! Condemning proprietary batteries since 1976 !=--

'I don't want them to believe me, I just want them to think.'
Marshall McLuhan

Comments

Total: 135, showing: 1 – 20
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In reply to:

Gollan: I feel bad for Sony owners who got burned by the firmware update. A simple "we will fix it" from Sony would go a long way here, but perhaps astrophotographers are not an important target market for Sony.

I like how you insult the people who do the in-field testing from which you benefit...

Link | Posted on May 6, 2017 at 00:29 UTC
In reply to:

mpgxsvcd: So if you can’t use Sony then what should you use for Astrophotography? Canon has been said to have poor dynamic range and poor noise performance. Nikon doesn’t have the software support that Canon does. So what is left Olympus and Panasonic? Fuji? CCD with all of its cost?

FWIW, the star tracker works by using GPS to know the camera location, then (as far as I know) it uses the same sensors (accelerometers) used for image stabilisation to know where the camera is pointed and shifts the sensor accordingly.
With the previous firmware, they added a feature so the rear display also offers a red tint mode, which does not throw off your eyes' darkness adaptation.

Link | Posted on May 6, 2017 at 00:22 UTC
In reply to:

mpgxsvcd: So if you can’t use Sony then what should you use for Astrophotography? Canon has been said to have poor dynamic range and poor noise performance. Nikon doesn’t have the software support that Canon does. So what is left Olympus and Panasonic? Fuji? CCD with all of its cost?

Do I know you @sh10453 ?
I think you can hardly say that I am preaching the K-1 much, considering how rarely I post here nowadays. You'll also notice I did not actually say that I own the K-1 here.
So how is your quip at me helpful to anyone? Does me owning the K-1 have anything to do that @mpgxsvcd included 4/3 cameras in their list but left out a 36MP full frame camera that has astrotracer and tether support? Hm.

Link | Posted on May 5, 2017 at 18:57 UTC
In reply to:

mpgxsvcd: So if you can’t use Sony then what should you use for Astrophotography? Canon has been said to have poor dynamic range and poor noise performance. Nikon doesn’t have the software support that Canon does. So what is left Olympus and Panasonic? Fuji? CCD with all of its cost?

Depending on your software requirements, check out the Pentax K-1.

Link | Posted on May 5, 2017 at 12:54 UTC
In reply to:

oldfashioned: great camera, no questions. but first nonsense: the flash mount. Second nonsense: memory stick (a waste of space). There must be a special office over there dedicated to that: combine marketing and nonsense for the pleasure of the boss (only). the customers? who cares

Misleading. Every manufacturer has an interest in a lock-in.
Sony bought the Minolta camera business. Minolta used this style of hotshoe. The A900 is a continuation of the Minolta lineage.
You will have noticed that the sony-born Sony cameras have a standard hotshoe. So don't blame the Minolta hotshoe on Sony's desire for customer lock-in.
Sony also allows third-party apps to run on their cameras, who else does that?
If you want to be mad at Sony, complain about the memorystick.

Link | Posted on Apr 25, 2017 at 12:02 UTC
In reply to:

maxmarra: I had a chance to play with this camera back in 2008. focus system was pretty rubbish (in comparison to my 40D) but FF sensor was Epic though U must be crazy to choose this over 5D

Lucky you, several of mine are on the list of problematic or incompatible lenses: https://www.panoramaplanet.de/comp/
And with a cheap chipped adapter they will even have shake reduction on the Sony.

Link | Posted on Apr 21, 2017 at 23:54 UTC
In reply to:

cshyde: Just to show the stupidity of that famous on-line auction site that starts with an E. There are A900 cameras selling for more than used A7 II bodies.

Was actually hoping for the A950 Andre mentioned maybe with liveview on the main LCD, but it became clear it was SLT only.

Link | Posted on Apr 21, 2017 at 12:45 UTC
In reply to:

naththo: That top of Sony A900 may be a breach of Pentax design copyright?

Because Sony has any reason to evoke the Nikon design aesthetics... ...much more plausible that they aimed for a retro style of a "generified" Japanese prism hump.

Link | Posted on Apr 21, 2017 at 12:41 UTC
In reply to:

OlyPent: Even with a price tag $5000 less at the time than Nikon's D3x, this camera wasn't exactly a sales winner, was it? The D850 was the downmarket version as I remember.

But the D800 was outsold by a factor of 1000:1 by spearmint chewing gum.

Seriously, are you surprised that Sony who were then a pretty small player in the ILC industry would have a pretty small market share?

Link | Posted on Apr 21, 2017 at 12:31 UTC
In reply to:

oldfashioned: great camera, no questions. but first nonsense: the flash mount. Second nonsense: memory stick (a waste of space). There must be a special office over there dedicated to that: combine marketing and nonsense for the pleasure of the boss (only). the customers? who cares

The flash mount was a carry over from Minolta, so it made some sense for Sony to keep it. Back then Sony Photo was a smaller company than now, without the resources to complete overhaul everything.

Memory Stick was actually a rather affordable storage medium, but I agree, it was a nuisance and IMO it should have been clear to Sony that this was a bad idea.

Link | Posted on Apr 21, 2017 at 12:29 UTC
In reply to:

Sdaniella: 2008 Canon ExpSim LV already available across the board APSC/APSH/FF EOS dSLRs
like prosumer Canon FF EOS 5DMkII w/1080p FHD Manual Capable M-Movie mode
True ExpSim LV = getting perfect exposures First-Time-Right (=never need to review for retakes; zero-chimpcentric)

2008 Sony prosumer FF dSLR ... A900 ... no Exposure Simulation Live Preview*
*unsaveable "no-storable-pic" exposure simulation live preview "mode"; to capture pic, one must turn mode off, then take a 2nd shot ... "chimping"-centric

ditto: 2009 Sony budget FF dSLR A850 no LV whatsoever ...

O_o

Do you have an equally uplifting message for people who value "ExpSim LV" less than some of the features the Sony *did* have?

Link | Posted on Apr 21, 2017 at 12:26 UTC
In reply to:

AndroC: This regular column always worries me in that it seems to focus on how much greater our current cameras are than ones released in the very close past. Here's an example this week of a camera that is still truly excellent. I get the impression that all DPR readers are professional sports photographers wanting highly performant AF and insane frame rates to nail the photo for the newspaper. But for landscape and still life photographers such as myself, the A900 and A850 are still beautiful and wonderful cameras, in no way obsolete. Luminance noise is observed at medium high ISO, but can be carefully removed in Photoshop et al, so it is not really a big problem. I use two A850's daily currently still and I am compelled to say I simply adore them. I am not saying they are the BEST CAMERA EVER that people are seeking, but for landscape, with good Minolta glass, they make luminous results of great beauty, with a warmth Minolta users know that's missing in many of the newer whizzo cameras.

Agreed, if you can carry an A850/A900 and a tripod, you can still swing it with the big ones.

Link | Posted on Apr 21, 2017 at 12:20 UTC
In reply to:

rfsIII: Everyone is complaining about the noise from this camera at higher ISOs, but maybe there's life left in the old girl yet. Has anyone tried processing the raws with a current version of Lightroom? It has a pretty powerful noise reduction algo.

I routinely used my A850 at up to ISO 1600 using Lightroom to process (and sometimes push) the RAWs. I think the problems were overplayed back then, but comparing it to my Pentax K-1, there is just no comparison beyond base ISO.

Link | Posted on Apr 21, 2017 at 12:19 UTC
In reply to:

maxmarra: I had a chance to play with this camera back in 2008. focus system was pretty rubbish (in comparison to my 40D) but FF sensor was Epic though U must be crazy to choose this over 5D

Not crazy at all.
A850 has in body stabilisation and a mirror that does not clash with old M42 lenses the same way the 5D's does. I had rented a 5D for a while and made the A850 decision without any regret.

Some people need superior AF performance and others are needlessly obsessed with it. Coming from a Pentax ist DS, the AF was good enough for me :D

Link | Posted on Apr 21, 2017 at 12:16 UTC
In reply to:

ZOIP: Still own one and use it for professional work sometimes, the appeal lies in three areas, the viewfinder and ergonomics are excellent but most importantly the colour/tonal rendition is just beautiful, as close to medium format neg film as we ever got with digital in my opinion.

Yep anything over 400 is a bit noisy but it can be cleaned up well enough, but in use I found 400iso really was 400, where as Canons I had at the time overstated their ISO so 400 on the Canons was really only about 250 ISO so the Sony disadvantage compared to the Canons was not really as great as it might at first appear.

The Canons in particular used a less dense red filters which helped high ISO performance but traded off colour quality, especially for ruddy skin tones, Sony chose to go with stronger filtering that traded off high ISO performance but liberated fabulous colour subtlety for the time and even for today.

The noise was largely a result of the red channel being far less exposed at a sensor level, but at low ISO it was fine.

I developed a whole system around shooting the A900 through a red/magenta filter with appropriate RAW processing, this equalised the cross channel exposure at the sensor level and liberated the most glorious colour, clarity and tonality I have ever achieved. Though effectively you are shooting at about 32 ISO.

Anyhow I still love mine and have never regretted the purchase.

Very interesting! Can you say what type of filter you used exactly?

Link | Posted on Apr 21, 2017 at 12:13 UTC

I went for the A850, but hopefully you'll allow my to chime in, considering how similar these cameras are.
I initially had many gripes about the A850 mainly to do with the user interface, but as time went by, we got along better and better. In the end, the K-1, its liveview focusing together with scandalously good ISO performance and my stash of Pentax lenses made me move it to backup camera.
Here's what flickr thinks are my most interesting images with the A850
https://www.flickr.com/search/?user_id=22070130%40N07&sort=interestingness-desc&view_all=1&text=a850

Link | Posted on Apr 21, 2017 at 12:11 UTC as 17th comment | 1 reply
In reply to:

RubberDials: "Micro Four Thirds persisted with the Four Thirds type sensor but by abandoning the mirror box (and the telecentric design philosophy) was able to fully deliver on the size benefits that had originally been promised."

Micro Four Thirds has not abandoned a telecentric lens design philosophy. All digital lenses are as necessarily telecentric as possible.

"Look at me, I am a native speaker, what I say is correct by default, hurr durr" :D

I can assure you that this is not a language issue on my part. I also didn't say that "as possible" is in itself meaningless (in fact I myself pointed out the constraints that you have now mentioned), but rather that this qualifier makes the combined statement meaningless.

"necessarily as telecentric as possible "

What do you mean by "necessarily", anyway? No dictionary definition of the word necessary, please :D

Your statement is meaningless, or maybe you like "trivial" better? What you are basically saying is that the lens is "necessarily" as good a compromise as possible from a range of sharp, colour-neutral, flare-resistant, cheap, weatherproof, parfocal, compact aaaaand telecentric. Does that strike you as meaningful? Not me.

Maybe it would be more constructive if we would simply agree that telecentricity is just one of the many important design considerations for digital lenses.

Link | Posted on Apr 21, 2017 at 12:06 UTC
In reply to:

RubberDials: "Micro Four Thirds persisted with the Four Thirds type sensor but by abandoning the mirror box (and the telecentric design philosophy) was able to fully deliver on the size benefits that had originally been promised."

Micro Four Thirds has not abandoned a telecentric lens design philosophy. All digital lenses are as necessarily telecentric as possible.

I realised that you didn't type correctly. The problem: It means nothing even when "corrected".

Your phrasing, thought to the end, implies that there is only one way of telecentricity, the "possible" one. That is not correct. If you look into scientific imaging and machine vision, we have lenses that offer extreme telecentricity, much more than any Olympus consumer lens. There is such a thing as a degree or a level of telecentricity.

Basically, "as possible" in this context is just a qualifier that makes your whole statement meaningless. Manufacturers need to trade off the desire for telecentricity against a host of different requirements. The logic of your statement could be applied like this: "Any digital lens is necessarily as sharp as possible."

BTW, there are reasons why you might want to add some degree of telecentricity to a lens, even if your imager is film, so your phrasing of "recording medium with a non-contiguous and angled array" is both ornate and misleading.

Link | Posted on Mar 18, 2017 at 00:23 UTC
In reply to:

RubberDials: "Micro Four Thirds persisted with the Four Thirds type sensor but by abandoning the mirror box (and the telecentric design philosophy) was able to fully deliver on the size benefits that had originally been promised."

Micro Four Thirds has not abandoned a telecentric lens design philosophy. All digital lenses are as necessarily telecentric as possible.

"All digital lenses are as necessarily telecentric as possible."

You do realise this sentence means nothing?
Any proofs for your other claim? Like Olympus advertising the µ4/3 lenses as telecentric?

Link | Posted on Mar 11, 2017 at 20:20 UTC
In reply to:

Richard Murdey: Why was telecentric lens design abandoned with MFT? Was it because sensors had evolved by that point with much shallower pixel wells, microlenses etc. such that it was no longer needed, was it because the distortions induced by non-telecentric lenses could be cleaned up in software, or was it because the mirrorless design somehow made it unnecessary?

The smaller flange focal distance certainly does not make telecentric design any less necessary.

In my opinion it is a combination: a bit of better microlenses & wells + a bit of software correction + mainly the need to offer a size advantage.

Link | Posted on Mar 11, 2017 at 02:00 UTC
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