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Messages - photonius

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1
Lenses / Re: Canon ef-s 17-55mm 2.8 is usm GONE
« on: Today at 08:49:59 AM »
Has anybody seen that the 17-55 is completely gone from the product page from canon usa? I noticed yesterday that the price was missing and if you clicked on it that you got redirected to the home page. Now it's completely missing from their product page.

Well, as we know, CANON USA has its own idea what to sell and what not (see EOS-M).
Presumably they want to keep flogging the  EF 28-135 on crop instead of the 17-55, maybe more profitable...   ;D

2
Lenses / Re: which telephoto for travel?
« on: February 24, 2015, 09:15:14 AM »
Quote
So, the question is whether any of you would recommend a different travel telephoto option?  In particular, I'm thinking about the possibility of switching out my 70-200 4L IS for a 135L.  Good idea or bad idea?

Bad idea, simply horrible. For someone that values portraits the 70-200 f4 is the ideal travel lens. A photographer with more general interests may wish to swap the larger aperture for increased focal length and get a 70-300 f4.x-f5.6.

A travel telephoto should be relatively lightweight, compact and flexible. The 135L scores for the first two but fails at being flexible whereas the 70-200 f4 IS suceeds:

  • You cannot control the background i.e. with subject the same size, 70mm will include more of the beautiful vista behind than 135mm.
  • You still cannot control the background i.e. with subject the same size, 200mm will cut out the distracting, cluttered or ugly part of the background that 135mm forces you to include.
  • 200mm at f4 gives you a sufficiently shallow depth of field that not having 135mm at f2 will likely not be an issue.
  • IS gives you low light capability and sufficient depth of field to get the subject/s in focus. The f2 aperture at 135mm means that even if you can get the subject in the frame you may not be able to get a deep enough depth of field.

Don't kid yourself about zooming with your feet; you'll be time limited with little control over backgrounds, angles and other gawping tourists and wanting to catch spontaneous shots so will have little time to relocate. The 135 is a general purpose telephoto prime but it makes for a very limiting general purpose travel telephoto.


regarding zooming with feet.  With longer focal lengths, the objects tend to be further away. As a consequence, foot zooming can be more tedious, i.e. if something is 400 meters away, to get closer to double it in size, you have to walk 200 meters. With a wide angle, when you shoot something you tend to be close, so maybe you only have to walk from 40 meters to 20 meters to get that church into the frame.
With landscape images (large distance to infinity) this consideration doesn't apply, as walking with any focal length makes little difference on the frame, the easiest way to frame is by choosing different focal lengths.

3
Lenses / Re: New Unique Macro Coming? [CR1]
« on: February 10, 2015, 06:27:09 AM »
My 15mm f2.8 fisheye with MFD of 15cm can focus as close as a macro.
Yes, but can you get 1:1 magnification? :)

Not sure how serious you are, but isn't a fisheye macro oxymoronic? 'True' macro implies 1:1 magnification of the subject at the sensor, but a fisheye has the widest field of view of any lens type. How could you have both simultaneously? My gut feeling is it's physically impossible, but I'm not an engineer.

The lens would have to be practically on the subject itself I imagine, it does seem oxymoronic I agree which is why I mentioned the idea in the first place :)

Well, I think those lenses are essentially endoscopes, so not really novel either.

4
Lenses / Re: New Unique Macro Coming? [CR1]
« on: February 10, 2015, 06:24:19 AM »
A zoom macro (1:1). Wasn't such rumored from Canon at some point, or have I been dreaming.

Yes, there was a patent for this. Indeed, it seems perhaps the most likely lens to be coming - maybe to replace
the 180mm macro. 
Nikon had a 70-180 macro, so a zoom macro is not exactly new. But the nikon could only do 1:3  at 70mm.
So, a zoom with IS that goes to 1:1 all the way, would be novel. 
people questioned the use of a macro zoom, but for long lenses, a zoom is really useful, because adjusting the frame would mean moving forward or backward over seizable distances, more than a focus rail usually can do.

5
EOS Bodies / Re: Canon Confirms Development of High Megapixel Camera
« on: December 31, 2014, 07:17:40 PM »
Let me propose, again, another approach Canon could potentially use.

Let's say this camera has 7DII pixels, and 52 million of them.

That means it has 104 million separate pixels because of the dual pixel design of the pixels.

The pixels can obviously be read separately or they wouldn't work for phase detection focusing in live view and video.

So, let's say the camera has a mode where the two halves of each pixel are read at different ISOs.  For sake of argument, let's say ISO 100 and ISO 1600 are used.

The result would be that the top four stops would have twice the shot noise they would have if you didn't do that because half of your data is clipped there.  But who cares?  The top four stops have so much signal that it really doesn't matter.  The overlapping range would be the same.  The bottom of the range would have something like 3-4 more stops of shadow performance due to the far lower read noise at ISO 1600.

Combine these two in a way similar to the way Magic Lantern dual-ISO works and you have a 15 stop or so DR image at 52MP.

Now, that 15 stop image won't fit into a 14 bit raw so you generate a 16 bit raw from your 14 bit * 2 raw data sets.

Now you have 80+MB raw files, give or take, with 52MP and 15 stops of base-ISO DR.


i proposed that already a long time ago when the 70d came out.
It seems canon is aware of this, but maybe cant make it work that easily (from some cryptic comments in interviews)
They may have even tried for the 7D II (causing the delay, extra firmware update for 7D).

6
EOS Bodies / Re: Canon Confirms Development of High Megapixel Camera
« on: December 30, 2014, 10:07:43 AM »
Quote
There is no problem of pixel size.

<physics>There is. </physics>

Yeah...let's talk about that.

I decided to calculate diffraction-limited resolution.  Here are the assumptions:  Green light (550nm), Bayer full-frame sensor, AA filter, MTF10 cutoff.  Here are the results:

f-stop Maximum MP count
1.4     8,333
2.0     4,167
2.8     2,083
4.0     1,042
5.7     521
8.0     260
11.3   130
16.0   65
22.6   33
32.0  16

So, does that seem like a problem to you for the foreseeable future?


your calculations seem off. For FF at f/4.0 a 115 Mp sensor would be diffraction limit.
see
http://www.luminous-landscape.com/tutorials/resolution.shtml

7
EOS Bodies / Re: Canon Confirms Development of High Megapixel Camera
« on: December 26, 2014, 09:02:50 AM »
"We are extending interchangeable lens groups (unsure what this actually means). We want to add one line to our EF lenses...I can't say any more than this. Please don't ask anymore (laughs)."

My interpretation is rather basic:
We are adding new lenses to our existing lens groups (ef, ef-s, ef-m). (not create a new range). Some announcements, patents, hints for such lenses have already been made.

The one lens that needs to be added to the EF lens group is a high-resolution UWA lens that can deal with the high res senors. Tele's and standard range have been updated already. The missing lens is probably the rumored/patented EF 11-24 (? I forgot the upper end focal length) zoom that hopefully would provide better sharpness in the corners.


8
Lenses / Yongnuo 50mm f1.4 AF lens
« on: September 29, 2014, 10:54:05 AM »
Looks similar to the Canon, same specs in terms of elements as the canon.

http://www.hkyongnuo.com/e-detaily.php?ID=353


Are the Chinese lens copies now coming?

9
PowerShot / Re: Official: Canon PowerShot SX60 HS
« on: September 20, 2014, 07:12:14 AM »
an interesting all-in-one travel camera with 21mm wide-angle, but no GPS....  :( no deal.

10
These are interesting rig-ups; I got a Reflecta CrystalScan 7200 a few birthdays ago but have been too occupied/lazy to use it so far. :-[ I am however saving it for the day when I feel motivated to scan some old (or new) material.

I wonder why nobody has so far posted any pictures that show the photographed and processed results.

Anybody?

based on this review it's not so useful for scanning thousands of slides because of the speed http://www.filmscanner.info/en/ReflectaCrystalScan7200.html
that's why copying slides at least with camera is faster. now, I still need some time... ;-)


11
good comments by eos650 and frodo.
I also made a slide copier set-up for similar reasons, see here: http://photonius.wikispaces.com/Slide+copier

The issue I haven't solved either yet though is how to do a good correction profile for negatives. (I have mostly slides, so negatives not a priority)

12


Congrats JD, but I'd advise staying away from either of those if all you've got is $15.  The drink is likely to come in a 1.75L plastic bottle and won't leave you feeling too well.  The other could result in a nasty legal or medical bill :o, if you don't get mugged in the process.

Natty Lite and Taco Bell might be more realistic and a tad bit healthier. 

On the other point, welcome to selling your photography.  You'll find out how individual taste really is when you sell your work.  The stuff you love rarely sells well, and vice versa.  The effort you spend taking a photo and editing it means almost nothing in most genres.  Only the final image matters.  If you don't believe me, here's a sampling of my work that one of longtime clients has chosen, and let me tell you, the rest of the work I've sent them for consideration is MUCH better. All of these shots were actually what I'd consider "outtakes" - shots that I took because I was there, not because I intended them for use/sale.  And they have used them for magazine ads, billboards, and huge prints in their branches!:







well, perhaps sometimes a more bland picture is desired in ads, to avoid taking away the focus from the message.

13
Lenses / Re: Filter for Tamron 150-600?
« on: June 13, 2014, 09:08:36 AM »
Hi guys,

thanks for your feedback - especially about the Marumi, as I hadn't heard much about them before.

I prefer Melitta or Folgers filters. Disposable, and inexpensive. they have some vignetting though  ;)

photonius, thanks.  You forgot to mention they biodegrabable too!  Not too sure about their UV filtering ability, but might make for a romantic misty feel to the shot as the lion is tyrying to rip my face off  ;)

Cheers guys!   :)

And you can use them to pad your wounds... ;)   

Seriously, from all I've seen, a UV/protector filter on these big teles is best avoided unless you have a special reason.
I've compiled filter info a while back, including links to the lenstip.com tests http://photonius.wikispaces.com/Filters
as pointed out, the marumi seems quite ok.



14
Lenses / Re: Filter for Tamron 150-600?
« on: June 12, 2014, 06:03:54 PM »
I prefer Melitta or Folgers filters. Disposable, and inexpensive. they have some vignetting though  ;)

15
EOS Bodies / Re: When Does the Year of the Lens Start?
« on: May 02, 2014, 05:35:11 PM »
As Eldar points out, the year has started.

We have:

Tamron 150-600 for Canon
Sigma 50mm f1.4 Art for Canon

more to come...

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