keepreal

keepreal

Lives in United Kingdom Enfield, United Kingdom
Works as a Retired, was Information Technology Manager
Joined on Mar 24, 2007
About me:

Amateur with a passion for pictorial photography of more than fifty years. Likes to communicate and learn from others with expert knowledge, especially if they also live in the real world, have galleries or links to really good photos and put their camera to good use.

Comments

Total: 282, showing: 81 – 100
« First‹ Previous34567Next ›Last »
On article DxO ViewPoint 3 adds automatic distortion correction (27 comments in total)
In reply to:

keepreal: There is one serious shortcoming in Viewpoint, at least as I see it, but I have a way around it. Please tell me if you agree or not. Possibly, something I need to set I have not yet discovered, though I have looked high and low.

If you want to compress the edges in an image, which I occasionally want to do with an ultra-wide angle image or a panorama for a landscape, it crops the top and bottom to the same pixel height, so the end result, while having compressed edges, also loses part of the image top and bottom. Weird. I also found this in Viewpoint 1.

So what I have to do is extend the canvas size top and bottom, apply the Viewpoint transition, then remove the narrower redundant top and bottom afterwards. It works, but what a chore.

Very clever, scastle. Many, many thanks. You have contributed everything to my use of VP!

I changed the default in Crop from preserve aspect ratio to unconstrained and now it does exactly what I want, just compressing in one direction while leaving the other unchanged.

I think DxO should let you choose the defaults or at least warn you in Help to check them all. Strange that crop has an influence on other functions even if you never intended to use it. Not how I would have designed it.

Link | Posted on Nov 18, 2016 at 17:44 UTC
On article DxO ViewPoint 3 adds automatic distortion correction (27 comments in total)

There is one serious shortcoming in Viewpoint, at least as I see it, but I have a way around it. Please tell me if you agree or not. Possibly, something I need to set I have not yet discovered, though I have looked high and low.

If you want to compress the edges in an image, which I occasionally want to do with an ultra-wide angle image or a panorama for a landscape, it crops the top and bottom to the same pixel height, so the end result, while having compressed edges, also loses part of the image top and bottom. Weird. I also found this in Viewpoint 1.

So what I have to do is extend the canvas size top and bottom, apply the Viewpoint transition, then remove the narrower redundant top and bottom afterwards. It works, but what a chore.

Link | Posted on Nov 18, 2016 at 14:14 UTC as 4th comment | 2 replies
On article DxO ViewPoint 3 adds automatic distortion correction (27 comments in total)
In reply to:

scastle: A quick review.

The automatic perspective corrections go a bit overboard and have to be dialled back some. The auto horizon correction, on the other hand, is often not enough. So,the auto corrections, at least in my experience, are better left in manual mode. I have not messed with the toytown tilt feature at all. Maybe I will find some picture that will benefit from it but (again IMHO) this is just a schnick-schnack.

What I like about Viewpoint is that that some of what it can do appears to be both unique and useful. But, after experimenting, I have to agree, scastle, that using manual almost always is better.

What impressed me most was correction for distortion with full frame fish eye lenses. I downloaded several from pixelpeeper to try that out and results were surprisingly good, allowing considerable correction towards the edges while leaving a large part of the centre unchanged, when that was imperative.

Having just spent a small fortune on a Nikon D610 and a Nikkor 20mm f/1.8, I am not now going to fork out on a fisheye but Viewpoint, IMO for the first time, makes such a lens a useful proposition. I do not like any distortion where I can correct it and the only reason I have little actual need of Viewpoint is that in landscapes with an ultra wide angle, or even in a panorama, one rarely can detect it even when it is there - in my kind of pictures, not everybody else's of that kind.

Link | Posted on Nov 18, 2016 at 10:59 UTC
On article DxO ViewPoint 3 adds automatic distortion correction (27 comments in total)

When I had an XP system, I bought V1 to compress the edges in images with an ultra wide angle lens. Hardly ever using it, I did not bother to upgrade for Windows 8.1 compatability but the special upgrade offer for the new V3 at 19 GBP changed my mind. Just now trying it out to correct perspective distortion on a shot I had a lot of trouble with, just press one button and there it is spot on.

BTW, wide angle lens do not distort at the edges, it is the geometry in real space and our mental recollection of what we think objects should look like, taken on board at less of an angle. However, our brains are designed to work on experience and as you cannot see more than vague blurred shapes outside of about 90°, it comes up with something different. For that, when it matters, DXO Viewpoint is worth having to correct it, regardless of what else it also can do. I will have to look into that and learn, see if it adds anything else new or better to my tool kit that I actually have a use for.

Link | Posted on Nov 17, 2016 at 20:18 UTC as 6th comment

Pretty daring to trust expensive kit like this to a drone but the result is lovely and beautifully edited. Please do it again when there is a little less mist and a little more sunshine. I'd like to see that too!

Link | Posted on Nov 3, 2016 at 09:19 UTC as 20th comment | 1 reply
In reply to:

keepreal: I would have liked a mirrorless camera to replace my Nikon D300 with the Sigma 12-24mm lens, that I use most because of the weight but last week finally gave up on the idea because no camera mount or lens combination suits me better. I ended up buying a Nikon D610 and Nikkor 20mm f/1.8, thereby saving 296g, too little but better than nothing and of course better IQ.

I have an EVF on my Olympus Pen but I do not like them at all. The A99 II weighs 849g, as much as my D300. In my opinion this only underlines the pointlessness of it, no need even to bother looking at its features.

Ever since digital, there has been a fashion in bigger and heavier which IMO is madness. Reviewers describe the new Tamron SP 150-600mm F5-6.3 as lightweight. Are they in the pockets of the manufacturers? So far, among the worst are those PRO lenses on MFT, whose size and weight is out of all proportion.

If I want to strengthen my arm muscles, I prefer to go to the gym, not buy a camera for the purpose.

Everlast66 I was only comparing the weight with my D300. My D610 is FF, slightly smaller and about the same weight. People who have no idea how to judge what a digital sensor or even film can record when looking at a scene directly or through an OVF loose less of the benefit by using an EVF, but I am not one of them.

Dave Oddie "The A99II is smaller than the original A99 it replaces and weighs 1 gram less than a Nikon 610." They and the D300 all are too big and heavy.

Nikon 20mm F2.8 is not that good. Weight is not to be saved regardless of everything else.

The A99II is "pointless" [to me, understood] not to everybody, just most of them. When I shoot my foot, at least I can see it properly in OVF, regardless of the light. Shooting in darkness no interest to me.

"As to the EVF...there are other advantages as well but you should be aware of those already if you have an Oly Pen." None for me.

"Plenty of other people get on fine with them, many seeing them as an advantage." True.

Link | Posted on Oct 26, 2016 at 14:23 UTC
In reply to:

keepreal: I would have liked a mirrorless camera to replace my Nikon D300 with the Sigma 12-24mm lens, that I use most because of the weight but last week finally gave up on the idea because no camera mount or lens combination suits me better. I ended up buying a Nikon D610 and Nikkor 20mm f/1.8, thereby saving 296g, too little but better than nothing and of course better IQ.

I have an EVF on my Olympus Pen but I do not like them at all. The A99 II weighs 849g, as much as my D300. In my opinion this only underlines the pointlessness of it, no need even to bother looking at its features.

Ever since digital, there has been a fashion in bigger and heavier which IMO is madness. Reviewers describe the new Tamron SP 150-600mm F5-6.3 as lightweight. Are they in the pockets of the manufacturers? So far, among the worst are those PRO lenses on MFT, whose size and weight is out of all proportion.

If I want to strengthen my arm muscles, I prefer to go to the gym, not buy a camera for the purpose.

Yes I did and also looked at just about everything else both similar and different. Too little time and space to give all my reasons here but Sony + Zeiss seems to be an expensive exercise in vignetting at every possible focal length, especially with very wide angle lenses. However good those lenses otherwise are, that is not acceptable. Moreover, giving up OVF with severe reservations about any of the camera and lens alternatives is not something I was prepared to do - as far as I am concerned it would just have been an expensive exercise in trading one set of reservations for another.

I think the best alternative would be a Leica M with Tri-Elmar but I would have had to sell my Lamborghini first.

Link | Posted on Oct 26, 2016 at 11:20 UTC
In reply to:

Poweruser: Ridiculous price

Tom,

The Sigma is much smaller and only weighs 470g so I expect everyone who owns it will want to replace it with this monster instead.

Link | Posted on Oct 26, 2016 at 10:19 UTC

I would have liked a mirrorless camera to replace my Nikon D300 with the Sigma 12-24mm lens, that I use most because of the weight but last week finally gave up on the idea because no camera mount or lens combination suits me better. I ended up buying a Nikon D610 and Nikkor 20mm f/1.8, thereby saving 296g, too little but better than nothing and of course better IQ.

I have an EVF on my Olympus Pen but I do not like them at all. The A99 II weighs 849g, as much as my D300. In my opinion this only underlines the pointlessness of it, no need even to bother looking at its features.

Ever since digital, there has been a fashion in bigger and heavier which IMO is madness. Reviewers describe the new Tamron SP 150-600mm F5-6.3 as lightweight. Are they in the pockets of the manufacturers? So far, among the worst are those PRO lenses on MFT, whose size and weight is out of all proportion.

If I want to strengthen my arm muscles, I prefer to go to the gym, not buy a camera for the purpose.

Link | Posted on Oct 26, 2016 at 09:54 UTC as 43rd comment | 7 replies
On article Sigma 12-24mm F4 DG HSM Art real world sample gallery (216 comments in total)
In reply to:

munro harrap: I tried the 14-24mm Nikkor. Well it can be useful to have such a field of view and then be able to narrow it down to get what you can make the most of, but not when there is the problem of the flare at the wide end all of the time. My lens was just NOT sharp, and to be able to focus it accurately REQUIRED the live view , because the AF was unreliable on a D800. This is due to the amount of possible choices of focus points within the vast depth of field available. These machines are untameable and ALWAYS go for the brightest highest contrast, so that you really do NEED a touchscreen. It is truly pathetic that they construct entire cameras and optical systems without involving reportage and sports photographers in the actual design at all, and then go on safari with a bunch of guys when it really is already too late, Even a sharp superwide needs a touchscreen, or accurate manual focus- but the "throw" is too narrow on such lenses to be accurate there too.

I am no expert on such matters, but surely the problem is that you need to change the focus mode not to switch focus points ad nauseam? How you best do this, I am not sure and perhaps, like I do with my Sigma 12-24mm, I always just use lock and hold on the central focus point. Of course this might not suit for fast moving subjects.

Link | Posted on Oct 7, 2016 at 09:22 UTC
On article Sigma 12-24mm F4 DG HSM Art real world sample gallery (216 comments in total)
In reply to:

Tieu Ngao: Many photos were taken at 12mm and share the same note "No lens correction", but some of them have heavy distortion and some have almost no distortion at all, which are unreal. Wonder why?

AbrasiveReducer

Few people seem to be aware of or understand the difference between perspective and distortion.

Also I agree that barrel and pincushion distortion are getting worse and worse as times passes, since the engineers rely on software to fix it. I abhor this because I only use RAW and choose software to develop it that does not have the ability to use profile corrections. What it does have is superior tonal gradation and the ability to merge frames at different exposures for HDR. PTGui can do that reasonably well too but also handles multiple sets to stitch a panorama and no way am I prepared to give either up.

Also, stretching the image to straighten it out again damages the edge and corner definition and leaves you with less of an effective angle, so the quoted effective focal length actually is fraud.

Link | Posted on Oct 5, 2016 at 07:55 UTC
On article Sigma 12-24mm F4 DG HSM Art real world sample gallery (216 comments in total)
In reply to:

Henry McA: Nice images! I like the Canon jpegs more. The lens is pretty wide - a comparison with the 11-24 L would be sweet.

Henry McA and pj1974,

I have the Sigma 12-24mm F4.5-5.6 EX DG HSM used on APS-C but better definition and a wider angle would be very much of interest to me for landscapes. Maybe with 8-16mm I would less often need to do panorama stitching. My 12-24mm is very even across the frame at all settings and I love the fact that there is no distortion at all since I only use RAW.

So, how do you find the Sigma 8-16 performs as regards distortion and do you have evidence of uneveness due to decentering, which photozone.de say is an issue?

Above, I also asked thx1138 about the Samyang 14mm f/2.8, where they say that distortion also is very high. However, I have the Micro Four Thirds Olympus m.Zuiko 12mm f/2 , which again they also says has high distortion but I find this generally not to be the case. I suspect that often the issue is that tests are made with the lens focused near on a chart whereas nearer infinity distortion with some lenses diminishes or may not even be apparent at all.

Link | Posted on Oct 5, 2016 at 07:38 UTC
On article Sigma 12-24mm F4 DG HSM Art real world sample gallery (216 comments in total)
In reply to:

mosc: Man 12mm is nauseatingly wide.

thx1138

According to http://www.photozone.de/canon_eos_ff/532-samyang14f28eosff?start=1 the performance of the Samyang 14mm f/2.8 is remarkable except that distortion is very high and vignetting is extremely high. So how do you find it in practice?

I have the Micro Four Thirds Olympus m.Zuiko 12mm f/2 , which photozone.de also says has high distortion but I find this generally not to be the case. I suspect that often the issue is that tests are made with the lens focused near on a chart whereas nearer infinity distortion with some lenses diminishes or may not even be apparent at all.

Link | Posted on Oct 5, 2016 at 07:10 UTC
On article Sigma 12-24mm F4 DG HSM Art real world sample gallery (216 comments in total)

Not that I am in the market for such a lens, but I hope it is at as non-distorting as my Sigma 12-24mm F4.5-5.6 EX DG HSM Mark I but really sharp to the edges on full frame. Otherwise, it is nothing to warrant such a name or price or the hefty size and weight. IMO lens sizes and weights, including this one, are getting to be lunatic, with many camera bodies not far behind even if they are beyond reproach on IQ.

Link | Posted on Oct 4, 2016 at 23:50 UTC as 35th comment | 5 replies

Ultra wide angle lens or panorama stitching? I am interested in the 7.5mm but...

Please have a look at my article https://www.dpreview.com/forums/thread/4061368#forum-post-58436937 and if you can offer helpful views on the matter, then so much the better.

Link | Posted on Oct 2, 2016 at 13:18 UTC as 1st comment
In reply to:

keepreal: Apart from a few compact primes, can anyone tell me why so many Olympus MFT lenses are so large and heavy, many of them have such outrageous native distortion? The cameras, E-M1 II apart are compact and lightweight, especially the beautiful Mini Leica like Pen-F. Silly name though for what ought to be called an E-M2, perhaps.The bodies may be 4/3 but most of the lenses are 16/3.

CharlesB58 In answer, large and heavy compared to the body size and some lenses even comparable to APSC, eg 7-14mm f2.8 PRO.

Some Olympus lenses test well but only with the standard raw converters or ignoring the wild distortion. brendon1000, I do not see why I should have to use one of them as my choice is based entirely on optimal tonal gradation for merged exposure bracketed RAW files for HDR.

Yes, I do actually have first hand experience to back up my view. See what equipment I own, recorded along with my profile.

"Apart from the PRO line, Olympus m4/3 lenses are as compact as expected for the sensor size..." So you want to exclude the "better" ones and then make your claim. What nonsense.

Proportionately to the camera body sizes and weights whether for MFT, APSC or FF, the mantra seems to be the bigger and heavier the better. Why not use technology to down size and down weight, like the OM1 for film FF? The fact that all the manufacturers are guilty does not make it right.

Link | Posted on Oct 1, 2016 at 12:27 UTC

Apart from a few compact primes, can anyone tell me why so many Olympus MFT lenses are so large and heavy, many of them have such outrageous native distortion? The cameras, E-M1 II apart are compact and lightweight, especially the beautiful Mini Leica like Pen-F. Silly name though for what ought to be called an E-M2, perhaps.The bodies may be 4/3 but most of the lenses are 16/3.

Link | Posted on Oct 1, 2016 at 07:04 UTC as 10th comment | 8 replies

I am hoping for good news about the new Laowa 7.5mm f/2 MFT. If it has minimal distortion, is sharp to the edges at f/5.6 and comes at a reasonable price, then this may solve all my problems. I may get rid of my bulky and heavy APSC outfit to instead rely upon my Olympus E-PL3 with VF-4 EVF.

My first camera is a Nikon D300 (OK there is better now) mostly used with the Sigma 12-24mm F4.5-5.6 EX DG HSM near to 12mm for landscapes. Mine is one of the good ones and that combination at smaller apertures satisfies me, even for very large prints. My hope is the new Laowa lens works as well on MFT.

There are better MFT cameras with more pixels but for my work this is not essential. Download the original at https://www.dpreview.com/galleries/3894780139/photos/3302669/ and view to a suitable size to judge that. But remember that in a matt print the demands are a little less. This was taken on the E-PL3 with the m.Zuiko 12mm F2 ED cropped to match my TV as monitor.

Link | Posted on Sep 22, 2016 at 12:43 UTC as 17th comment | 1 reply

Is this pyramid selling? I mean the crowd funding part. Surely, nobody is going to tell me this is made to a very high tolerance for cine users. I am sure I am safe, unlike elsewhere where I commented on similar lens offerings.

If anyone wants it, I have a pack of six rolls of bread for $100 + PP $35. Please get in touch.

Link | Posted on Sep 11, 2016 at 12:15 UTC as 7th comment | 1 reply
In reply to:

keepreal: There must be a lot of idiots out there. Otherwise we would not see lenses from Cooke and other manufacturers as such ridiculous prices. I am sure they are nowhere near worth anything, even a lot less than the asking prices.

I would be a lot happier if people with more money than they know what to do with gave it to help those in the poverty trap get educated and motivated to better themselves. Some do of the own accord, but not that many can see how. The divide between the rich and poor has widened since the 2008 credit crunch, the wealthy mostly escaped the consequences but the mostly innocent less well off have faced the brunt of it.

If I thought there would be any chance of success, I'd like to see a worldwide boycott of Cooke, Meyer and other manufacturers behaving like this - not just in optics or photography, by the way.

Thematic "I have flagged your dpreview account for abuse and hope you get banned." Should I return the favour of trying to ban you for going off the deep end? Have you ever heard of free speech?

I warrant that a premium is justified if there is a market for products manufactured to closer tolerances but that does not justify extortion. Unless of course, they are designed to photograph the dark side of the moon from earth, in which case prices like these sound just about right.

Link | Posted on Sep 6, 2016 at 21:55 UTC
Total: 282, showing: 81 – 100
« First‹ Previous34567Next ›Last »