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: 351, showing: 61 – 80
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In reply to:

aris14: Like it or not m43 offers more convenient, versatile and light gear than other system.
The quality/cost ratio is great too, not to mention the integrated facilities/abilities comparing to APS/FF implementations. Oh well, except maybe the 1-2% special cases in photography for which an FF/MF is required.

> And no, an f/2.4 lens does not let as many photons hit a sensor as an f/1.2 lens. It blocks more photons.

Again, you either wilfully obscure the argument by omitting the crucial sensor area which I went to some length of explaining or you lack understanding why it is important to include.

Here is an appropriate *complete* statement, which is a rephrasing of my original point in the hope you understand it now:

"At a given diagonal angle of view, an f/2.4 lens projecting onto a FF sensor lets the FF sensor collect as many photons per time as an f/1.2 projecting onto a fourthirds sensor allows that fourthirds sensor. "

If you don't understand why the above is a complete statement and yours isn't, then you will not understand this discussion, so I suggest you do some further reading. Or maybe ask me, so I can clarify whatever misunderstanding you have.

Link | Posted on Mar 4, 2018 at 16:06 UTC
In reply to:

aris14: Like it or not m43 offers more convenient, versatile and light gear than other system.
The quality/cost ratio is great too, not to mention the integrated facilities/abilities comparing to APS/FF implementations. Oh well, except maybe the 1-2% special cases in photography for which an FF/MF is required.

Not sure either Kubicide, as you don't understand how photography works. :(

Your statement of "a same sized pixel" is irrelevant, as you take a photo with the entirety of the sensor not a single pixel. The single pixel would only be relevant for "photons per square mm" - and the whole point is that you take a photo with the entirety of the sensor so "photons per square mm" is not relevant.

Are you wilfully obscuring the argument or do you really think this is a valid argument?

Also, stop liking your own posts, it's childish.

Link | Posted on Mar 4, 2018 at 16:03 UTC
In reply to:

bluevellet: If I were in the market for a new FF DSLR, this would be a tempting camera body. But lens selection is very limited and there's no real third-party support so I'd probably opt for the D850 to get the most bang for my buck.

Too bad.

24-120/4 would be nice, but the 28-105 is a very nice and cheaper compact universal zoom that I am very happy with. But there is no denying that there are some gaps in the Pentax line up and what is worse is that those gaps cannot be filled by the modern high-quality offerings from Tamron, Sigma and Tokina.

That said, Pentax also has some interesting lenses that are difficult to get natively in other systems, so it will depend on what you want to use your system for.

I would definitely recommend that people who are thinking about investing in a new-to-them FF system spend half an hour investigating whether these restrictions would hamper them or if maybe combining the current offerings with just-discontinued last-generation lenses would tick all their boxes.

Link | Posted on Mar 4, 2018 at 15:13 UTC
On article CP+ 2018: Hands-on with Laowa 'Magic Shift Converter' (119 comments in total)
In reply to:

babart: Unfortunately, it seems strange one would need the Canon or Nikon mount to mate to a Sony alpha. That means if you own a Sony you have to buy a Canon model Laowa to get the shift. Meaning one can't use the Laowa as 12mm without buying a Canon to Sony E adapter. Why not a shift adapter for the Sony E to Sony E? Or did I miss something in the text?

Yup, given the different gear you have, that might be an interesting addition for you.

Link | Posted on Mar 4, 2018 at 14:22 UTC
In reply to:

ogl: Nikon and Canon users could use newest Pentax DFA*50/1.4 in Tokina's version.

Fair point, but fast fifties have had a strong re-awakening for quite a few years, not sure how much street cred there is in yet another one.

Link | Posted on Mar 4, 2018 at 13:51 UTC
In reply to:

aris14: Like it or not m43 offers more convenient, versatile and light gear than other system.
The quality/cost ratio is great too, not to mention the integrated facilities/abilities comparing to APS/FF implementations. Oh well, except maybe the 1-2% special cases in photography for which an FF/MF is required.

@Kubicide I think you need to decide whether you want to talk f-stops or aperture (=diameter).

For same diagonal FOV:

Do you compare a 50/1.4 on fourthirds with a 100/1.4 on FF?
Then you have same f-stops and same photons per area and time. Which means FF collects four times ("2 stops") more photons per time and sensor.

Or do you compare a 50/1.4 on fourthirds with a 100/2.8 on FF?
Then you have same aperture diameters, same DOF, same number of photons per time and sensor, although the photons per mm² will be less on the FF setup.

What was the point? Well, you said

> I don't see f/1.2 12mm lenses from any of the big brands

This is not what you should look for. A 24/2.4 lens lets as many photons hit a FF sensor per time as the 12/1.2 does on fourthirds. And 24/2.4 lenses are nothing special. There are great 24/1.4 for FF. You'd need a 12/0.7 on fourthirds to capture as many photons per time and sensor. (f/0.7 is the physical limit you can achieve for photographic lenses.)

Link | Posted on Mar 4, 2018 at 13:48 UTC
On article CP+ 2018: Hands-on with Laowa 'Magic Shift Converter' (119 comments in total)
In reply to:

babart: Unfortunately, it seems strange one would need the Canon or Nikon mount to mate to a Sony alpha. That means if you own a Sony you have to buy a Canon model Laowa to get the shift. Meaning one can't use the Laowa as 12mm without buying a Canon to Sony E adapter. Why not a shift adapter for the Sony E to Sony E? Or did I miss something in the text?

Yes these exist and are pretty good:
http://aboutphotography-tomgrill.blogspot.co.uk/2014/01/tilt-shift-adapter-on-fuji-x-e2-x-pro1.html

Normally I would say that getting a fullframe 12mm for APS-C is wasted money, but if you want/need the shift, tilt or tilt&shift, it's still a very interesting combo. But I am in no position to confirm (or deny) whether the 12mm works with full tilt and shift on APS-C.

Link | Posted on Mar 4, 2018 at 13:25 UTC
On article CP+ 2018: Hands-on with Laowa 'Magic Shift Converter' (119 comments in total)
In reply to:

babart: Unfortunately, it seems strange one would need the Canon or Nikon mount to mate to a Sony alpha. That means if you own a Sony you have to buy a Canon model Laowa to get the shift. Meaning one can't use the Laowa as 12mm without buying a Canon to Sony E adapter. Why not a shift adapter for the Sony E to Sony E? Or did I miss something in the text?

The more lenses you have, the more sense the adapter(s) make.

Of course, if money, weight and bulk are no issues, you get the native lenses every time.

The shift use is rather specialised, so you use your normal lenses with the normal MC11/Metabones adapter and when the time strikes for shifting, it will be marginally more cumbersome than having native lenses. No big deal.

I am sure Laowa won't be mad at you if buy their 12/2.8 and their 15/4 Shift as native FE ;)

Link | Posted on Mar 4, 2018 at 02:21 UTC
In reply to:

aris14: Like it or not m43 offers more convenient, versatile and light gear than other system.
The quality/cost ratio is great too, not to mention the integrated facilities/abilities comparing to APS/FF implementations. Oh well, except maybe the 1-2% special cases in photography for which an FF/MF is required.

> These lenses let more light in than what is typically available in other formats which helps in the sensor size/noise trade-off.

Their light density (photons per area) is higher, but it pretty much has to be, because the light density is summed up over a smaller area than APS-C or FF.
What really is interesting is the "amount of photons per image" and here the larger formats usually have an advantage. Unless you have to have a certain deep DOF, in which case it doesn't really matter.

Link | Posted on Mar 4, 2018 at 02:10 UTC
In reply to:

Ben O Connor: I wish to own one of those Panasonic-Leica tele lenses for my gx80. However, I have hard time to get one. Price is a definately the main issue, since I have been married and can´t decide what to buy myself only :)

But in the other hand, their size is also not very small compared to APS-C glass of pentax for example. I rather want to compare Pentax glass, because they designed specially for that sensor size. Pentax 200mm F 2.8 attached on a K-30 is exactly same size combo compare to GX80+200mm F2.8 pana leica.
K-30 + Sigma 150-500 is significantly larger combo compare to GX80+100-400mm pana leica but it has longer range and smilar light sucking capabilities coupled with more affordable price.

I guess I will wait till Pana-leica 100-400mm get down to sub 1300€ range, But probbably only a second hand of that lens be that low on price.

Long story short; suck to be poor & married. Al Bundy. I feel you man :)

The Panaleica 100-400 has a 135 format equivalent aperture of feq/12.6 at feq=800mm

The Sigma 170-500 on APS-C is feq/9.5 at feq=750mm.

That is 0.4 of a stop but ridiculously smaller.

Also, thank you Ben, I had no idea you could do lens comparisons :-O

Link | Posted on Mar 4, 2018 at 02:06 UTC
On article CP+ 2018: Hands-on with Laowa 'Magic Shift Converter' (119 comments in total)
In reply to:

babart: Unfortunately, it seems strange one would need the Canon or Nikon mount to mate to a Sony alpha. That means if you own a Sony you have to buy a Canon model Laowa to get the shift. Meaning one can't use the Laowa as 12mm without buying a Canon to Sony E adapter. Why not a shift adapter for the Sony E to Sony E? Or did I miss something in the text?

I think you misunderstood what I meant with hollow tube: Just a hollow tube, without any shift. You need one Canon->FE hollow tube adapter and the MSC to get the 12/2.8 and 17/4 Shift ability with your Sony FE camera.

And yes, of course this was made specifically for Sony FE cameras. Not sure what is confusing about this? Canon and Nikon are the most commonly adapted-SLR-to-FE lens mounts that exist, so that is why Laowa went this route.

Link | Posted on Mar 4, 2018 at 00:28 UTC
On article CP+ 2018: Hands-on with Laowa 'Magic Shift Converter' (119 comments in total)
In reply to:

babart: Unfortunately, it seems strange one would need the Canon or Nikon mount to mate to a Sony alpha. That means if you own a Sony you have to buy a Canon model Laowa to get the shift. Meaning one can't use the Laowa as 12mm without buying a Canon to Sony E adapter. Why not a shift adapter for the Sony E to Sony E? Or did I miss something in the text?

Maybe someone can come up with a shifting teleconverter that does not need the extra space granted by the difference in the flange registers, seems unlikely to me, but who knows.

And the thing is that FE users can get this lens, a cheap hollow tube adapter and the magic shift converter to give them two lenses. Of course, if they already use Canon EF lenses, then they might prefer the MC11/Metabones plus the MSC.

The complaints about the adapters are somewhat misguided:

1. The MSC does things no other converter (and actually system) can do and is both smaller and cheaper than adding a 17/4 Shift to your 12mm lens.

2. This is a manual focus lens. As such, there is less benefit to a "native" solution. And even in AF lenses, the current iterations of the MC11/Metabones adapters are pretty darn good.

3. Many "native" FE mount lenses are just SLR lenses with integrated hollow tube adapters. You are not saving any bulk with them (to the contrary!) but you reduce flexibility.

Link | Posted on Mar 3, 2018 at 23:48 UTC
In reply to:

ogl: Nikon and Canon users could use newest Pentax DFA*50/1.4 in Tokina's version.

No point in "first dibs" for Pentax as with previous rebranding/sharing of lens, Tokina will not offer Pentax mount and Pentax of course will only offer Pentax mount, which leaves the rather unrealistic target market of Sony FE and Canon users who might use the Pentax version via an adapter rather than wait for the Tokina (assuming the Pentax has mechanical aperture because otherwise it cannot even be adapted...)

Link | Posted on Mar 3, 2018 at 18:54 UTC
In reply to:

jnd: 50mm is the most competitive focal length, I'm not sure how they expect to get good amount of market share when there are already almost 10 other SLR models. Let's see:

Canon EF 50mm f/1.4 USM
HD Pentax-D FA* 50mm F1.4 SDM AW
Nikon AF-S Nikkor 50mm f/1.4G
Samyang/Rokinon 50mm F1.4 AS UMC
Sigma 50mm F1.4 DG HSM Art
Sony Carl Zeiss Planar T* 50mm F1.4 ZA SSM
Zeiss Milvus 50mm F1.4
and Zeiss 55mm f/1.4 Otus Distagon

Then there is also Tamron 45mm f/1.8 Di VC USD and couple other slower models.

For full disclosure, the current Pentax DA 55/1.4 actually covers 24x36 as shown here and elsewhere: http://erphotoreview.com/wordpress/?p=4563

The real irony is of course that the future Pentax DFA 50/1.4 looks suspiciously like the Tokina lens in different clothes. ;)

Link | Posted on Mar 3, 2018 at 18:52 UTC
On article CP+ 2018: First Look - Sony 400mm F2.8 G Master (462 comments in total)
In reply to:

rbach44: Let me save you all some time and sum up the comments below:

The Sony crowd: WOW! A 400m 2.8?! So long! So fast! Sony is on a roll! This will be the game changer for all of photgraphy. The SLR is dead, now all the pros will be using A9s. Nikon will be going out of business tomorrow, just like we’ve been saying for 5 years now.

The Canikon crowd: What’s the big deal? Haven’t we had this since the 90s? Aren’t mirrorless lenses supposed to be smaller? Why are people so excited about a plastic model behind glass? I’m confused...

Of course we have had great 400/2.8 lenses for decades now. Such a new design still shows a strong commitment by a brand to their camera line up and the field of sports photography in particular. As a Pentax user the 400/2.8 reminds me of a better time for the brand, so I can understand the excitement of the Sony users.

Link | Posted on Mar 3, 2018 at 16:15 UTC
On article CP+ 2018: First Look - Sony 400mm F2.8 G Master (462 comments in total)
In reply to:

Tazz93: I guess imitation is really the sincerest form of flattery.

It is a white 400mm lens, so of course it is imitating the Minolta AF lenses of days gone by.
http://www3.xitek.com/testreport/xitek/maf-g-tri.htm

;)

Link | Posted on Mar 3, 2018 at 16:10 UTC
On article CP+ 2018: First Look - Sony 400mm F2.8 G Master (462 comments in total)
In reply to:

WongFeiHong: It does look like Canon counterpart, but holy crap I bet it is 50% smaller than Canon's 400mm 2.8 II and 45% lighter too!... wait, maybe going to cost £13k ha ha ha...

Mirrorless can save some space.
Ignoring collapsible lenses, this is especially true in the wide angle regime, where you need less of a retrofocus group (gives more vignetting though) or can move the retrofocus group into the space that would normally be occupied by the mirror box.
Arguably, you can also use that space for a telephoto group, but for a lens this long and this bright, those 20mm are really not gonna save you anything, neither money nor size.

Link | Posted on Mar 3, 2018 at 16:06 UTC
On article CP+ 2018: Hands-on with Laowa 'Magic Shift Converter' (119 comments in total)
In reply to:

babart: Unfortunately, it seems strange one would need the Canon or Nikon mount to mate to a Sony alpha. That means if you own a Sony you have to buy a Canon model Laowa to get the shift. Meaning one can't use the Laowa as 12mm without buying a Canon to Sony E adapter. Why not a shift adapter for the Sony E to Sony E? Or did I miss something in the text?

You missed that the magic shift adapter needs an SLR lens (with longer flange register) and a mirrorless camera (with short flange register).
Also, using Canon-mount lenses on the Sony FE cameras via Metabones or Sigma MC11 adapters is very common so this will be seen as not a problem by many.
If Laowa would design a 17/4 shift lens from scratch for the FE mount, it would probably be better (need fewer glass elements) but this way you get two very useful lenses for a very good price. (Assuming you already have a standard adapter.)
Laowa also make their 15mm shift macro, but that, too is a native SLR lens that would need an adapter (or a hollow tube) to mount on the FE cameras.

Link | Posted on Mar 3, 2018 at 15:28 UTC

Not the type of photography I do, but I really appreciate the mix of story telling, nature explanation and gear talk as it relates to the task he wants to accomplish. Great photos, too.

Link | Posted on Mar 3, 2018 at 15:06 UTC as 59th comment | 1 reply
In reply to:

theprehistorian: Apart from the Nikon D850 and Sony A7RIII, there's nothing much out there to get excited about. As far as camera bodies go anyway, there're some interesting new lenses, however.

I bought a D850, I've kept my D810, the only camera I'd like to upgrade is my GR, but Ricoh seem to have lost interest unfortunately.

The GR III has been shown on a "leaked" Ricoh/Pentax roadmap.
I doubt such a niche camera can shake up the market, but on the other hand it makes me optimistic that it is planned.

Link | Posted on Mar 3, 2018 at 14:47 UTC
Total: 351, showing: 61 – 80
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