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...)

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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: 165, showing: 61 – 80
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On article Yongnuo YN 85mm F1.8 lens now available (251 comments in total)
In reply to:

drdocmatt: No-one seems to have noticed that Canon owns Yongnuo ..

You mean the 2015 April Fool's joke?
https://fstoplounge.com/2015/04/canon-buy-knock-off-brand-yongnuo/

Link | Posted on Feb 21, 2017 at 11:26 UTC
On article Yongnuo YN 85mm F1.8 lens now available (251 comments in total)
In reply to:

tkbslc: Yongnuo is having a lot of fun with Canon's expired patents.

At minimum? And then you give one reason that isn't even a reason: Do you understand that lens styling and lens optical design have no direct relationship? This lens's plastic housing looks the Canon, but that has nothing to say about the innards.
And it is unlikely that the styling is protected by a patent. Patents don't usually cover stuff like this. However, styling can be protected via trademark, which does not run out after a certain time. So that would not support your claim either.

How would you have proof? Dunno, maybe post the patent for us. You know, it's publically available and then we can discuss. You shouldn't make baseless claims such as this.

Link | Posted on Feb 19, 2017 at 05:01 UTC
On article Yongnuo YN 85mm F1.8 lens now available (251 comments in total)
In reply to:

TerrificShot Photography: At this price, this is not a surprise. A while ago, I ordered the Yongnuo 35 mn lens because it was the only cheap alternative to the Canon 35mn. I was simply disappointed by the same issue as this new lens : blurry corners, noisy autofocus

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Best,
Herve
http://www.terrificshot.com/blog

Mark, this lens is an 85/1.8 - so it does have a rather large aperture. On which sample photos do you base your assessment of the sharpness? (Also, there are other reasons to buy primes, but that's another story.)

Link | Posted on Feb 19, 2017 at 04:50 UTC
On article Yongnuo YN 85mm F1.8 lens now available (251 comments in total)
In reply to:

tkbslc: Yongnuo is having a lot of fun with Canon's expired patents.

So to recap, you have absolutely no proof and are just repeating hearsay and uninformed rumours.

Link | Posted on Feb 19, 2017 at 04:43 UTC
On article Yongnuo YN 85mm F1.8 lens now available (251 comments in total)
In reply to:

tkbslc: Yongnuo is having a lot of fun with Canon's expired patents.

Which Canon patent are they using?
If you mean the normal Canon 85/1.8, then the optical arrangement is different: 9 Elements in 7 groups for the Canon, 9 elements in 6 groups for the Yongnuo.
It's not impossible that there is an old Canon patent that Canon never used, but how likely is that? So, could you provide a link that proves that either the optical formula stated is a lie or that they have used another patent?

Link | Posted on Feb 19, 2017 at 03:05 UTC
On article Yongnuo YN 85mm F1.8 lens now available (251 comments in total)
In reply to:

TerrificShot Photography: At this price, this is not a surprise. A while ago, I ordered the Yongnuo 35 mn lens because it was the only cheap alternative to the Canon 35mn. I was simply disappointed by the same issue as this new lens : blurry corners, noisy autofocus

--------
Best,
Herve
http://www.terrificshot.com/blog

These are not counterfeit lenses. counterfeit: "made in exact imitation of something valuable with the intention to deceive or defraud". These clearly do not say Canon anywhere. And the optical arrangement is different, too (9 Elements in 7 groups for the Canon, 9 elements in 6 groups for the Yongnuo). They do use a similar cheap plastic styling as Canon. But that's not "counterfeit".

Link | Posted on Feb 19, 2017 at 03:01 UTC
On article Action-packed: Sony a6500 review (1181 comments in total)
In reply to:

bowserb: I have no concern about 4k video. However, this camera's in-body stabilization that works with or without in-lens stabilization, is why I cancelled my pre order for the Canon M5. Now, if someone can just make a reliable, fully functional EF/EFS to Sony E adapter, this is my new camera.

Sorry for the late reply. This is very encouraging to hear, thank you!

Link | Posted on Feb 13, 2017 at 09:43 UTC
On article Action-packed: Sony a6500 review (1181 comments in total)
In reply to:

bowserb: I have no concern about 4k video. However, this camera's in-body stabilization that works with or without in-lens stabilization, is why I cancelled my pre order for the Canon M5. Now, if someone can just make a reliable, fully functional EF/EFS to Sony E adapter, this is my new camera.

Brechtlam, if you were to rank the MC11 performance for Sigma, Canon and Tamron/Tokina lenses, would there be a stark difference and how would they stack up?

Link | Posted on Feb 7, 2017 at 04:23 UTC
On article Sigma 85mm F1.4 Art DxO results: a new king is crowned (249 comments in total)
In reply to:

falconeyes: Bokeh set aside, this is the first 1:1 MTF comparison of Sigma 85/1.4A vs. Nikon 105/1.4E
-> https://www.dpreview.com/reviews/lens-compare-fullscreen?compare=true&lensId=sigma_85_1p4_dg_hsm_a&cameraId=nikon_d810&version=0&fl=85&av=1.4&view=mtf-ca&lensId2=nikon_105_1p4_e_ed&cameraId2=nikon_d810&version2=0&fl2=105&av2=1.4

The figures for the 105/1.4E have been stunning, but the 85/1.4A is almost a new all time record (it just failed to beat the Otus 55/1.4).

Unfortunately, both the 85 and 105 have shorter focal lenghts than claimed: 80mm and 95mm. I.e., there relative difference in focal length is closer to the claim: 19% rather than 24% difference.

Sorry, I was on mobile and could not do a proper investigation regarding infinite focus. I do notice that this is something many less-expert testers do not consider, but as several of you have pointed out, DXO does.

Link | Posted on Feb 3, 2017 at 17:34 UTC
On article Sigma 85mm F1.4 Art DxO results: a new king is crowned (249 comments in total)
In reply to:

Fred Joseph: Measured focal length of 79.7mm???? What does that mean? Is the lens short-changing the owner by 5mm?

I was wrongly hopeful: As FalconEyes discussed below, they test the lens at infinity.
You gotta appreciate Pentax calling their 77 a 77, their 43 a 43 and their 31 a 31. It even became became a trademark of sorts.

Link | Posted on Feb 3, 2017 at 17:33 UTC
On article Sigma 85mm F1.4 Art DxO results: a new king is crowned (249 comments in total)
In reply to:

falconeyes: Bokeh set aside, this is the first 1:1 MTF comparison of Sigma 85/1.4A vs. Nikon 105/1.4E
-> https://www.dpreview.com/reviews/lens-compare-fullscreen?compare=true&lensId=sigma_85_1p4_dg_hsm_a&cameraId=nikon_d810&version=0&fl=85&av=1.4&view=mtf-ca&lensId2=nikon_105_1p4_e_ed&cameraId2=nikon_d810&version2=0&fl2=105&av2=1.4

The figures for the 105/1.4E have been stunning, but the 85/1.4A is almost a new all time record (it just failed to beat the Otus 55/1.4).

Unfortunately, both the 85 and 105 have shorter focal lenghts than claimed: 80mm and 95mm. I.e., there relative difference in focal length is closer to the claim: 19% rather than 24% difference.

have these focal lengths really been measured at infinity or at test-chart distance?

Link | Posted on Feb 2, 2017 at 19:07 UTC
On article Sigma 85mm F1.4 Art DxO results: a new king is crowned (249 comments in total)
In reply to:

Fred Joseph: Measured focal length of 79.7mm???? What does that mean? Is the lens short-changing the owner by 5mm?

Many lenses reduce focal length when focusing close (internal focus). Unless they specified "at infinity", they might have shot a test subject that was relatively close and calculated the focal length from that. (Sorry, I cannot access their review now to find out if that's the case.)

Link | Posted on Feb 2, 2017 at 19:06 UTC
On article Adobe Creative Suite 6 has been officially retired (352 comments in total)
In reply to:

robbinsbox: The last results from adobe showed subscription model working for them.
Dont really like it myself and have been playing with Affinity which will be fine as a PS replacement.
But how to replace LR, whıch ıs the one I use most of the tıme.

Edward, that is interesting I will have to try and see what happens. It definitely must be "phoning home". I agree, version 5 was completely quiet on my netports. But starting with 6.0 (when they introduced the CC version and made the standalone version kind of hard to buy or even find on their website) things have definitely become a lot more big brother is watching you!

Link | Posted on Feb 2, 2017 at 18:51 UTC
On article Adobe Creative Suite 6 has been officially retired (352 comments in total)
In reply to:

robbinsbox: The last results from adobe showed subscription model working for them.
Dont really like it myself and have been playing with Affinity which will be fine as a PS replacement.
But how to replace LR, whıch ıs the one I use most of the tıme.

Edward, I do not use Lightroom mobile (it actually says my Trial expired, but I never even trialled it knowingly), but it is (was?) my understanding that you need be signed in to LR/Adobe in order to fully use LR, even locally?
I guess your approach makes sense, I just didn't realise this was an option.

Link | Posted on Feb 2, 2017 at 05:25 UTC
On article Adobe Creative Suite 6 has been officially retired (352 comments in total)
In reply to:

robbinsbox: The last results from adobe showed subscription model working for them.
Dont really like it myself and have been playing with Affinity which will be fine as a PS replacement.
But how to replace LR, whıch ıs the one I use most of the tıme.

Why replace Lightroom? I really like the software, but Adobe's licensing scheme is taking away rights from users. Recently my PC crashed and I somehow got signed out of my standalone copy of LR. No biggie, I thought. I then applied an LR update. Only to find after restarting that Adobe's license server thought I was running one copy of LR too many and reverted me to a trial license. I had to engage with Adobe customer service, who, after their chat crashed a few times, were quick and helpful, to be fair to them.
However, this sort of hiccup with the standalone I find troublesome for what problems might surface if LR goes subscription only. Therefore, it is great to have other options available.

Link | Posted on Feb 1, 2017 at 12:56 UTC
On article Adobe Creative Suite 6 has been officially retired (352 comments in total)
In reply to:

robbinsbox: The last results from adobe showed subscription model working for them.
Dont really like it myself and have been playing with Affinity which will be fine as a PS replacement.
But how to replace LR, whıch ıs the one I use most of the tıme.

ACDSee has come a long way, wow, thank you for the heads-up!

Link | Posted on Feb 1, 2017 at 02:02 UTC
In reply to:

belle100: Can we also have versions for Nikon F-mount please.

There is a Leica-M autofocus adapter that uses a miniature gear motor. It is possible. Whether it gives the performance people would expect from a Nikon lens, I don't know...

Link | Posted on Jan 25, 2017 at 00:18 UTC
In reply to:

Robert Zanatta: What is "auto ramping"?

Fascinating, I am a MechEng and it is great to see the range of things you can do with a PID :) You say outliers (I guess clouds temporarily blocking the sun and similar things) are removed. So I am guessing the algorithm needs a few images to stabilise? Something between 5 and 10 shots, maybe?

Would your algorithm also cope with the camera rotating from lit area to shade? Or would the camera's auto exposure mode be better, because the range is not large enough to cause problems?

Link | Posted on Jan 13, 2017 at 06:41 UTC
In reply to:

Lee Saxon: Are they just aping the appearance of the Canon, like the new Voigtlander 58 does the Nikon Ai ? Or does it actually rip off the optical design? I'm not a *huge* fan even of the former, but if it's the latter DPReview should not be promoting it (even if the patent is technically expired).

"Yongnuo already sells 35mm F2 and 50mm F1.8 lenses in Canon and Nikon mounts with each mount having a corresponding barrel design to match of the camera brand’s own. "

This and the different optical formula hint at "just aping the appearance".

As to your last point, where do you draw the line what is okay to promote? Sigma reverse-engineering the EOS protocol? Sigma coming up with a mount that is basically a clone of the EOS mount? Metabones reverse-engineering two protocols to steal camera sales from Canon and lens sales from Sony? (Or give Canon lens sales and Sony camera sales, who knows...)

Link | Posted on Nov 2, 2016 at 23:02 UTC
In reply to:

Angrymagpie: Fantastic idea! We need more of these. Maybe an adapter where you can slide in different grades of ND filters and other filters instead?

I had that idea and DIYed IR and ND adapters. Without a proper machine shop, I wasn't able to manufacture a light-tight way of switching out the filter, so I sealed the filter into the adapter.
It works okay, but the glass has an effect on corner sharpness of wide angle lenses. Which is unfortunate, because I hoped this kind of filter could be used for extreme wide angle lenses that cannot take a filter. It should still be useful for telephoto-lenses, as the angle of incidence will be reduced and the glass has less effect.

Link | Posted on Oct 27, 2016 at 22:51 UTC
Total: 165, showing: 61 – 80
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