joejack951

joejack951

Lives in United States United States
Joined on Jul 22, 2010

Comments

Total: 198, showing: 1 – 20
« First‹ Previous12345Next ›Last »
In reply to:

Deardorff: 5 inches for macro work. What is the magnification factor? Close isn't necessarily 'macro'.

Think about it, on a 24x36mm sensor at 1:1, what is the size of an object that is 18mm across? Is it 18mm or some other value? On a 12x18mm sensor at 1:1, what is the size of that 18mm wide object? Is it 18mm or some other value?

I didn't say that the number of pixels was relevant to the magnification specification. I noted that a 1:1 image is still 1:1 after cropping, but that the pixels will be decreased. Higher pixel density sensors (like a 16mp m4/3 sensor vs. a 16mp full frame sensor) will put more megapixels on a 12x18mm object than the lower pixel density sensor.

Yes, cropping is irrelevant to magnification. 1:1 is still 1:1 no matter how much you crop. Cropping just changes the effective size of the sensor. Just like using a m4/3 sensor is simply cropping from a full frame sensor, only with a m4/3 sensor, you can't ever get back to the full frame size.

Direct link | Posted on Apr 13, 2015 at 13:15 UTC
In reply to:

Deardorff: 5 inches for macro work. What is the magnification factor? Close isn't necessarily 'macro'.

1:1 on full frame is still 1:1 on m4/3 or any smaller or larger format. Crop to 1/4 of the frame of a full frame 1:1 image and you'll have a 18 x 12mm image (practically the same square mm's as m4/3). The difference will be how many pixels you put on the subject.

Direct link | Posted on Apr 12, 2015 at 22:23 UTC
In reply to:

ccclai: Equivalent to F2.8 in full frame?

As Mike99999 points out above, with full frame you just shoot at two stops higher ISO and get roughly the same noise as m4/3s due to the fact that the same 'total light' is being captured. 4X the light on a sensor 1/4 of the size evens things out between the two sensors. Again, the difference with full frame is that you get AF and a cheaper lens.

IBIS is something that could give the m4/3 camera an advantage if the scene was static. No arguing there.

Direct link | Posted on Apr 5, 2015 at 03:45 UTC
In reply to:

ccclai: Equivalent to F2.8 in full frame?

ozturet, the Nikon covers a sensor that is four times larger than a m4/3 lens so it can be up to two stops slower and still capture as much or more light than a m4/3 lens. At f/0.95, this new Voightlander lens is just under two stops faster than the Nikon. Picking a nit really, but the lack of AF and higher price are still real cons.

Direct link | Posted on Apr 3, 2015 at 18:45 UTC
In reply to:

ccclai: Equivalent to F2.8 in full frame?

Yup, pretty much equivalent to the new Nikon 20mm f/1.8, just at $450 more for a slightly slower and likely worse performing lens with no AF. These Voightlander lenses have their uses I'm sure, but competing with full frame is not what they are good at.

Direct link | Posted on Apr 3, 2015 at 14:30 UTC
In reply to:

HowaboutRAW: Which Fuji body?

Would be interesting to see the differences between XTrans and Bayer.

I never denied a diameter difference. However, given that on both cameras the lens does not extend past the limits of the body, the diameter of the lens has little effect on the overall size of the camera. The length of the lens does change the size and this Fuji is within 2mm of the length of both Nikon's and Canon's 50/1.4 lenses.

If you are going to use terms like 'light gathering' you should use them correctly. 'Light gathered' is dependent on f-stop and sensor size. Without specifying a sensor size, all you know is the light density and that is a meaningless property for comparing lenses.

As far as the Fuji being better than Nikon's 'best', comparing the two lenses at Photozone I'd have to disagree. Even at the same f-stop, the Nikon appears to out-resolve the Fuji by a decent margin though the Nikon is being used on a higher MP sensor (24 vs. 16). However, at equivalent apertures, the Fuji lags really far behind.

Direct link | Posted on Feb 18, 2015 at 14:20 UTC
In reply to:

HowaboutRAW: Which Fuji body?

Would be interesting to see the differences between XTrans and Bayer.

Nikon 50mm f/1.4 AF-S G - Dimensions (DxL) Approx. 2.9 x 2.1" (7.37 x 5.33 cm)

Fuji 35mm f/1.4 XF R - Dimensions (DxL) Approx. 2.56 x 2.16" (65 x 54.9 mm)

Fuji is ever so slightly longer but smaller in diameter.

Yes, 52mm f/2.1 in DOF/light gathering. Bested by the lowly $200 Nikon 50mm f/1.8 AF-S G even. I'm sure it's a great lens for a Fuji camera but if I am comparing systems, full frame simply offers better value when it comes to fast lenses.

Direct link | Posted on Feb 18, 2015 at 02:06 UTC
In reply to:

HowaboutRAW: Which Fuji body?

Would be interesting to see the differences between XTrans and Bayer.

Considering that it is the equivalent of a full frame 52/2.1, one would hope that it is smaller than a full frame 50/1.4. However, the Fuji is only smaller in diameter than the current Canon and Nikon 50/1.4 but a little longer than both. It is larger in every dimension that the screw drive Nikon 50/1.4 AF-D.

Direct link | Posted on Feb 17, 2015 at 23:18 UTC
In reply to:

joejack951: Not that I am a professional who plans on entering or anything, but I love how my Nikon D3s isn't good enough for this contest but a Samsung Galaxy S5 phone is.

Any camera can yield great results in the right hands at the right place. That doesn't excuse them from placing an arbitrary limit on the most foolish of all camera specs on which they could place one. Do they really think a 30"x20" print (or larger) from an S5 will look better than one from a D3s, D700, A7s, 5DC, etc.?

Direct link | Posted on Feb 17, 2015 at 21:06 UTC

Not that I am a professional who plans on entering or anything, but I love how my Nikon D3s isn't good enough for this contest but a Samsung Galaxy S5 phone is.

Direct link | Posted on Feb 17, 2015 at 01:19 UTC as 22nd comment | 3 replies
In reply to:

JDThomas: For the price it's not very versatile. I'd stick with my Nikon 16-35 f/4. With Nikon's high ISO performance f/2.8 isn't a necessity and lenses this wide aren't really used for shallow depth of field.

It better be a heck of a lot sharper than the Nikon. My 16-35 is sharp as can be.

The Nikon 16-35/4 has VR. But, a stop faster and a little wider for the same money and only trading off 5mm on the narrow end (equivalent to a small crop) seems like a really nice deal for the Tamron. Wide lenses aren't 'typically' used for shallow DOF shots but they certainly can be. Look at the sample photos for the new Sigma 24/1.4 for instance. If you get close, you can get some nice separation at wider apertures, a look that I personally enjoy.

Direct link | Posted on Feb 14, 2015 at 05:36 UTC
In reply to:

SteB: As I've mentioned before, I'm a bit baffled by this 90mm macro lens. I'm sure it will be a good performing lens, but it is a bit big for a 90mm macro, especially for a small mirrorless camera. It looks very much to me like a DSLR lens design adapted to a short back flange distance. It also seems a bit expensive for what it is. I don't see how it would perform any better than a 90mm Tamron or Sigma 105mm. In fact I highly suspect it is based on the 90mm Tamron. The optical layout I saw was very similar to Tamron with a few differences. I suspect the differences are to adapt it to Sony's version of IS from the Tamron variant.

A full frame 90mm lens is not typically (ever?) a retrofocus design on a DSLR so the additional flange back distance of those camera has little to do with the size of the lens, unlike some wide angle designs. That means mirror or not, the lens will be about the same size for that focal length. However, mirrorless cameras might have some advantage in being able to place lens elements closer to the sensor but I don't know if that plays out as an advantage in reality.

Direct link | Posted on Feb 13, 2015 at 13:55 UTC
On Canon EOS 5DS / SR First Impressions Review preview (2975 comments in total)
In reply to:

Howard: I bet Sony and Nikon breathed a sigh of relief.

Same DR as the 5DIII, seriously? So it's an "improvement" in quantity not quality of pixels.

I will take a more serious look at Sony's next offering.

I recognize that there are times when multiple exposures won't work, or work as easily as a single exposure. But, a single exposure with severe brightness adjustments isn't perfect either; in the cases where multiple exposures are possible, that technique will always yield a cleaner final result.

Direct link | Posted on Feb 6, 2015 at 16:43 UTC
On Canon EOS 5DS / SR First Impressions Review preview (2975 comments in total)
In reply to:

Howard: I bet Sony and Nikon breathed a sigh of relief.

Same DR as the 5DIII, seriously? So it's an "improvement" in quantity not quality of pixels.

I will take a more serious look at Sony's next offering.

If you aren't shooting off a tripod, what's the point of using a 50MP camera? Might as well use a 5D MkIII and save yourself some money and file storage space. And there are plenty of awesome wedding/event photographers out there shooting Canon without DR issues. The 'DR issue' seems only to exist on DPR forums and DXOMark as far as I can tell.

Direct link | Posted on Feb 6, 2015 at 15:43 UTC
On Canon EOS 5DS / SR First Impressions Review preview (2975 comments in total)
In reply to:

Howard: I bet Sony and Nikon breathed a sigh of relief.

Same DR as the 5DIII, seriously? So it's an "improvement" in quantity not quality of pixels.

I will take a more serious look at Sony's next offering.

If you are looking to make the most of the 50MP resolution of this camera, you are shooting on a tripod. If you are shooting on a tripod, bracketing a few shots and combining them is little extra work, and will always yield a better result than a 5-stop shadow push, too. I shoot Nikon but all this whining about Canon sensors is getting pretty old.

Direct link | Posted on Feb 6, 2015 at 14:07 UTC
In reply to:

Dave Oddie: The focal length range is very useful. On APS-C i use a Sony 11-18 which is similar. Usefully wider then the 16mm on my CZ 16-80.

The problem with the Tamron though is with it being a FF lens is size and weight.

I can't help thinking if I was a FF user I'd be happier with a 24-105 zoom complimented by a 17mm prime lens for the wide angle forgoing the flexibility of the zoom.

Does anyone make a 17mm FF prime these days? It all seems to be zooms which are large and expensive.

Relative to the f/1.4 lenses, Nikon's 28/1.8 and 35/1.8 FX lenses are also pretty small and light. Canon's 24/2.8 IS and 35/2 IS aren't what I'd call huge either.

Nikon's 18-35/3.5-4.5 makes for a very light alternative to this new Tamron lens as well, if a zoom is what you are after.

Direct link | Posted on Jan 30, 2015 at 14:31 UTC
In reply to:

Dave Oddie: The focal length range is very useful. On APS-C i use a Sony 11-18 which is similar. Usefully wider then the 16mm on my CZ 16-80.

The problem with the Tamron though is with it being a FF lens is size and weight.

I can't help thinking if I was a FF user I'd be happier with a 24-105 zoom complimented by a 17mm prime lens for the wide angle forgoing the flexibility of the zoom.

Does anyone make a 17mm FF prime these days? It all seems to be zooms which are large and expensive.

There are a number of 14mm f/2.8 primes for full frame (Canon, Nikon, & Samyang) and Zeiss has an 18mm f/3.5. The latter is a good bit slower, manual focus, no stabilization, and still half a kilo or so. I'd grab the Nikon 16-35/4 or 18-35/3.5-4.5 over it just about any day.

Fairly certain that Nikon made a 17mm prime back in the 70s or so but I have no idea how good it is. Definitely manual focus though.

Direct link | Posted on Jan 26, 2015 at 17:35 UTC
In reply to:

Kodachrome200: People still use filters?

Fixing an uneven sky is doable, I'm sure, but I wouldn't want to spend that time if I didn't have to. If a shot had a lot of water and sky in it, the effort could be worth it. But if just using the polarizer for a deeper blue sky, it is likely easer to just deepen the sky in post than to fix an uneven sky.

Direct link | Posted on Jan 25, 2015 at 17:32 UTC
In reply to:

Kodachrome200: People still use filters?

Polarizers only have issues on ultra wide angle lenses with lots of sky in the frame (which becomes uneven in color). If using the polarizing to control reflections on water or the like, it will work just fine regardless of focal length. The latter case for a polarizer is the one where post-processing won't work as an alternative, too.

Direct link | Posted on Jan 24, 2015 at 05:00 UTC
In reply to:

John C Tharp: This lens is unique, yet it's market position is a bit awkward; a fast aperture with stabilization is great for a number of uses, but the unsealed nature of the lens combined with the difficulty of using filters, along with some stiff first-party (and third party) competition means it might not be as popular as it is cool. And it is cool.

If you intend to consider this lens, why would you take it over the other lenses already available in the same focal length?

For Canon users, it is the first time they'll have a native zoom lens wider than 16mm and f/2.8.

For Nikon users, it is much cheaper than the 14-24/2.8 zoom.

For both camps, it is the first f/2.8 wide angle zoom with image stabilization. It is also the first zoom going wider than 16mm and longer than 24mm.

For those reasons, it is pretty interesting to me.

Direct link | Posted on Jan 24, 2015 at 00:52 UTC
Total: 198, showing: 1 – 20
« First‹ Previous12345Next ›Last »