Never met a Tamron lens I didn't like. I used many of them when Tamron had the Adaptall II mount and the BBAR designations. The adaptal II mount let you use the lens on many mfr camera lens mount systems. They came with one adaptor of your choice, and if you had two platforms, you simply purchased another adaptor.

I used a 28-200 and found it sharp and smooth. I used it on a Canon EOS AIIe. I shoot mostly car shows and detail and image sharpness are very important to me. Tamron delivers in all the examples I have used or owned.

I used a Tamron 28-270 (current model) and still feel the same.

My favorites have been the older manual focus adaptall mount zooms. Most of those were in f2.8 aperture.

My opinion is that overall Tamron makes good lenses. However, that is with the warning that every manufacturer makes a dud now and then...... even Nikon and Canon, although one would expect that not to be the case. Go figure!

Gosh!! You make it sound like New Zealand is on the other side of the world.

Signed:

Oregon in the great Pacific NorthWest of the US. The left side of the North American Continent.

I can't go either, but it's because I got lost in the Badlands about five years ago. Just walked out about 2 months ago.

I just don't think I can face that risk again.

If you go out hiking, take a compass and leave a note with the head camp counselor what direction you are headed.

Have fun.

Now that Panasonic finally got on board with IBIS (In Body Image Stabilization), I am not sure I would pony up the money for the Panasonic Lumix lens.

Olympus started putting IBIS in the bodies of their DSLR's and Mirrorless with the advent of the E510 (some years ago).

Panasonic on the other hand used the in lens image stabilization, meaning more expensive lenses, because you bought the system in each lens. Now the GX7 does have In Body Image Stabilization.

However, the IBIS in the OM-D (EM5) and the new EM1 is based on stabilizing the camera on 5 axis, which I suspect is more advanced than the IBIS used in the Panasonic GX7

Even though Panasonic and Olympus share the same sensor and the same lens mount in mirrorless, they do little else the same across the two platforms, even down to the process engines and the AA lowpass filtering (or lack of it with Olympus).

The implication is that the Olympus, with the advent of E-PL1 weakened the AA filtering for increased OOC sharpness, which I took advantage of when that camera came out. It worked... sharper images.

Panasonic did not follow that route, and reviews showed at the time that the Olympus was sharper. However, and I have not read anything on the Panasonic, whether by the GX7, Panasonic has done anything similar, such as reduced AA or removed AA filtering.

Olympus was the first, being the more creative of the two. Nikon followed up with a new AA filter treatment in the Nikon D800E...(not the D800), and also with the D7100.

The D600/D610 do not benefit by removal of the AA filter.

Other mfrs are working with this newest approach to the AA low pass filtering. It is effective in creating sharper images straight out of the camera. I have personally found this to be true with the first approach to this by Olympus.

I purchased the E-PL1 the moment it hit the market and was very surprised at the sharpness advantage incorporated in the camera.

Every vendor at these events have the same problem you do with this issue. People are crude and crass to take pictures of anyone's art work, even those artists with pottery, sculpture, woodwork, jewelry, etc. Stealing ideas for artwork is not new and a vulgar practice, simply because it is done with such an air of entitlement.

I would check the policy with the people who jury or manage the events and see what they have in place about people taking pictures.

Otherwise, posting a sign is probably a good idea.

Cell phone or not, it's the first step leading to copyright theft.

I hang out with the Pencil Eraser crowd... simple #2. Do NOT use the white erasers with grit in them, ie. for ink.

Just a simple eraser as on #2

Another thing that accelarates dirty contacts is smoking.... nicotine tars like to break electronics connections with coating the contacts.

55

SS, thanks, and I agree with you... Sneaker Zoom is the real advisable work in getting bird photos. The closer you are, the better the shot, including crawling over a rock, or through some mud to get to those Pink Flamingo's.

Also, admittedly the AA thing is controversial and raise ire rapidly in disagreement. I happen to believe in it, due to my experience, and I do not, and never have had problems with Moire, but that, as you imply, is a whole nother discussion.

Thanks for your comments. I do believe in doing the work to get closer to the shot. However, when your trying get the shot from the North Rim of the Grand Canyon, Sneaker Zoom is not advisable, perhaps even fatal. :shock:

Back again because I wanted to post this separately.

I have used this company to repair/re-cement lenses:

http://www.focalpointlens.com/fp_intro.html

A good lens repair where disassembly is included is better done by a company that has a Lens Collimation Bench, to get it back together right. Focal Point uses proper techniques and proper lens collimation. Not cheap, but responsive and quick turnaround in the cases I presented to them. Easy to work with.

Go to their services tab on the home page and scroll down to read the section on fungus and haze.

Bottom line, to have fungus, the lens has not been properly cared for or stored.

Fungus, as indicated by the word "fungus", is a living creature that feeds on the coatings on the lens optics. So, it depends on how advanced the fungus is.

And, like toe nail fungus, it travels from lens to lens given the opportunity. I would not put a lens with fungus in the same bag along with my other lenses. Have it cleaned first.

Optical characteristics indicate that fungus, haze or marks on a front element do not often affect image quality, if not too advanced or large. Rear element defects are more likely to affect image quality.

Don't let your good lenses shower in the same stall that has previously been used by a fungus ridden lens.

:XD:

Seriously, don't expose your good lenses to a lens with fungus.

Can't speak to the image resolution portion of this question, BUT as I mentioned in my previous post, you won't get the extended reach if you use the 400 on full frame. It will only be a 400mm lens. On your 1.6 crop sensor, the lens will be a 560. Aperture/stop values will be the same as you do not lose any light values coming through the lens.

Light values reaching the sensor on a given lens remain the same, whether the light is reaching a FF, a 1.6 crop, or a 2X crop. It's the physics and optics of the lens. The lens does not change in actual length. The extra effect for reach is the nature of the sensor size. The optics of the lens and the physical length remain constant. f2.8 or f4 are still f2.8 or f4, as stated on the lens.

If I use a 400 on my Olympus M43, it effectively becomes an 800mm lens. That's reach for birding and wildlife.

Compare that to purchasing a real 560, or 800 if you elect to go Full Frame. What is more important the extended reach for the money, or the marginal increase in image quality.

An option that would get you into contemporary sensor country and very likely the same image quality as full frame would be the new D7100 (Without the AA filter for increased sharpness, which you only get in full frame if you purchase the Nikon D800E. The lesser D600/D610 still have the older standard AA filtering reducing sharpness over the D7100 and D800E)

So a crop sensor D7100 and retaining the extended reach of the FF lenses would be a nice balance for both Image Quality and reach, ie... birder, wildlife, event, sports where longer reach would pay off.

I would still opt for the best crop factor/longest reach, and the best Image Quality, which again is my logic for purchasing the new Olympus EM1 with 2X crop, fastest industry focus, and 5 axis Image Stabilization.

Special Note: I used the Nikon camera's to illustrate the effect that removing "low pass - AA filtering" is adding to image sharpness out of the camera. The effect is pretty amazing, and Olympus also was one of the first to reduce or remove AA filtering some time ago on their EPL-1 when it came out.

As far as I know at this point, Canon has fallen behind on this technical move, and is not yet removing the AA filtering on any of their camera's, so matching contemporary image sharpness on sensors leaves Canon in the "wake" so to speak.

If I weren't persisting in the Olympus EM1, for the added reach, My camera choice would be the Nikon D7100, primarily to mix a higher megapixel count and the increase in image sharpness brought about by taking out the AA filter completely. That one move of removing AA filtering alone is significant as a sole advance for sharpness OOC. Reviews are showing that to be the case.

Wonder when Canon will GTST on this?
:thumbup:

-

I did my term of full frame. I purchased a Canon 5D when they were new, and had one L lens.

Couldn't get back to a crop factor camera fast enough. Fortunately sold the 5D for a $100 loss, because I didn't mess around long before making the decision.

Don't get me wrong... it was a great camera, wonderful images. But I determined full frame was not for me.

My budget does not allow for the "tarrif" or "resultant surcharge" that comes with owning full frame and pondering lens prices for all that oversized optical glass.

In addition, I soon learned, and this is a budget issue as well, that the additional reach of a 1.6 crop factor was going to be cost savings as well for longer glass. Getting over 400mm using a 300mm lens is a big plus, on both the wallet and the "carry weight".

Significant.

All things considered, your 50D and my D200, gave as good a result on image quality as their contemporary Full Frame counterparts.

I'm now seriously considering the EM1 Olympus, where the crop factor is 2X, wherein a 200mm lens equates to 400mm. Also much of the HG and SHG Olympus and Panasonic lenses equal the image quality of L lenses from Canon and Nikon pro lenses.

However, I do submit that this is a very personal issue, and I do think you should invest $5000 in equipment... one body and two EF L lenses, and pack a bag of full frame around for a few months before you make a final decision about the rightness of the move for you.

:shock:

For any number of years now, I have always carried a small brush with me, particularly for use on Zoom lenses. My favorite looks like a lipstick tube, and the brush extends/retracts by taking off the cover and twisting the end.

Whenever I zoom my lens inward, I do not worry about dust, but when I zoom my lens to extend it, I first take out my little lipstick like tube, take off the lid, twist the end to extend the brush and carefully brush off any dust around the joints of the lens. Then I compose and take the picture.

I have, over the years, allayed my mistrust of zoom lenses and the dust problem.

I don't know what to tell the OP as regards dust. I can say, I have never seen what little dust shows up in my lenses to actually appear in my images. Frankly, the nature of lens optics is such that dust near the front objectiv will rarely, if ever appear in an image. However, dust resting on the rear objectiv may occasionally affect the image.

I will admit, particularly to those who follow the wisdom of my posts, that I have often been accused of being somewhat Anal Retentive, if not worse, and a trouble maker to boot.

Good luck with the lens. Solutions require persistance, an overbearing manner, and sometimes fisticuffs.

:hunf:

No help on the D600 here. However, I do have a friend who was quite happy with his Canon XSi. He went to a presentation on In Camera HDR. He bought a Canon T4i strictly for the feature.

He took some images and seemed happy with the HDR. He's a committed Tripod user.

He is now frustrated with the T4i HDR feature. He finds that when he shoots wildlife (example.. ducks floating/swimming slowly) on a pond, he gets ghosting in the images... ie. two heads on the ducks. Static subjects.... OK.

So now feels, after quite a bit of experimentation that he would have been just as happy to stay with his XSi and passed on the T4i.

My conclusion... HDR seems to have it's place, but you can't show his duck pictures to anyone and try to make them believe that you came upon a flock of two-headed ducks.

Now, the gentleman is not a "pixel peeker" by anyone's stretch of the term, but I agree with him. It was an expensive lesson, and suggests to me that HDR is for Static subjects only and in the case of landscape.... no wind allowed.

You don't need a dark room and I have not needed one for some years.

Daylight processing is done in a tank, and you load reels in a dark changing bag. Requires a bit of practice.

In fact, I even avoid the routine chemicals, and use Instant coffee, vitamin C and washing soda. I process the film and also do enlargements and process the paper in the same. I do admit that enlarging requires a dark space.

No dark room.... use daylight tanks, process in Caffenol, and then scan, or send for printing, either negative or digital image.

If I caught your attention with Caffenol, here are two sites that are blogs/forum oriented on the process. It's a kick.

I informally call my Caffenol prints..."Coffee Break Images".

The two sites:

http://caffenol.blogspot.com/

http://www.caffenol.org/

Shoot film and self process... enjoy yourself and avoid the digital mayhem.

When I do send film for developing, I do use Walmart. You can be a Walmart Hater, but it's costing you.

At my request, Walmart sends my 35mm and 120 roll film on their "send out" basis (deposit film in their Fujifilm kiosk) directly to Fuji Pro Labs, on their trucks and back. Time out - ten days. The envelopes are not open in Walmart stores going or coming back. You get a phone call in ten days when the film is back. Processing and prints, less than $10 and no ship charge.

I know it's "campy" to be a Walmart hater, but this service is so good, I do it, and I don't wear a disquise walking into or out of the store.

If you re-evaluate your hatred of Walmart, you are welcome to PM me and I will send you the long story about how the "send out" process is done. If you just walk into any Walmart and ask about this process, your are most likely just going to get a blank stare, or a denial of the service.

I've been doing this for Ten years at my local, as you so disdainfully say "Wally World", and have never paid the going rate of camera stores, received professional results, and never lost a roll of film. I particularly do this with medium format film, because digital simply does not meet the IQ standards of medium format film or larger format.

Borrowed but appropriate.

Convenient, As I Found This Just Yesterday. Posted on RFF.

Proper attribution at the end of the gentleman's article.

Here Goes:

"Film and digital resolution compared
________________________________________
It is commonly stated on the internet that a good 35 mm frame of ISO 100 film has a resolution equivalent to 20-25 MP. However, although this figure has some truth to it, it does not reflect what we find when film and digital are compared in real life. Unfortunately, every test I’ve encountered on the web has serious flaws – the fact that the comparisons contradict each other in every detail bears witness to this. So, the answer was to do my own investigation...


I'd be interested if anyone can find any major flaws in my argument. These calculations are of course somewhat crude, but suffice to give ballpark figures.


What none of these web comparisons addresses is the need to consider bottlenecks in equipment that impact the theoretical resolution of film – i.e. lens resolution and scanner resolution (assuming images will be scanned). Consider a typical scan of 35 mm film at a scanner resolution of 2700 ppi: the resulting file has dimensions of about 3800 × 2400 pixels = 9 MP – but this is not equivalent to a 9 MP image from a digital camera because both are theoretical values based solely on the number of pixels, and fail to account for differences in resolving power between the two mediums. Comparing, say, a 20 MP film scan with a 20 MP digital camera image is thus comparing apples with oranges. What we actually need to compare is the resolving power of frame of film and a digital sensor.


Basically, the ad men and marketing executives have co-opted the term "resolution" to mean something far removed from its true meaning, thus sowing confusion. "Resolution" has little directly to do with pixels and file size, and is correctly "the ability of an optical instrument or type of film to separate or distinguish small or closely adjacent objects".


Resolution is governed by the Nyquist–Shannon theorem. This states that the maximum frequency (the Nyquist frequency) that can be resolved without loss of information is twice the sampling frequency. Applied to digital photography (both digital cameras and scanned film), the sampling frequency is the resolution of the sensor or film (measured in line pairs per millimetre, lp/mm), and the Nyquist frequency is the resolution in megapixels (MP) needed to resolve all the information recorded by the sensor or film. Thus,

R = (2rh × 2rw)/10^6 = 4r^2hw/10^6

where r is the recorded resolution of the sensor or film (measured by experiment), h is the height of the sensor or film, w is the width of sensor or film, and R is the sensor or scanner resolution in MP needed to resolve the recorded detail.

(Note: I can't type superscripts, so ^ denotes that the following number is a superscript, e.g. 10^6 = 10 to the power 6.)



The real-world resolution of a digital sensor

We need to know how much a typical 35 mm full-frame dSLR can resolve. Rather than consider a top-line camera, let’s consider something more affordable – the Canon 5D Mark II. It’s a 21 MP camera, but this is not a direct measure of its resolution – it’s simply the number of pixels it records. Tests (see DPReview) show that this dSLR has a resolution of about 58 lp/mm. From our equation,

R = (4 × 58^2 × 24× 36)/10^6 ~12 MP



35 mm film

Typical professional 100 ISO colour negative film (Kodak Extar, etc.) has a resolution of about 70 lp/mm (as measured in tests – see film manufacturers’ websites), which is about the same as a dedicated film scanner (not a flat-bed scanner – which destroys resolution – even the best like the Epson V750 cuts this by half, to ~35 lp/mm). The formula gives

R = (4 × 70^2 × 24× 36)/10^6 ~ 17 MP

35 mm colour film thus records a little more detail than most 35mm full frame dSLRs. However, 35 mm colour film has a lot of ‘noise’ (i.e. grain), so that, visually, the smoother-looking dSLR image is preferred by most people, despite having slightly less visible detail overall. (Low-ISO B&W film has much higher resolution and less grain, and can show more detail than medium-format digital backs.)



Medium-format film

The formula gives the following for 645-format film, if we assume medium-format lenses resolve equally to 35 mm lenses:

R = (4 × 70^2 × 45× 60)/10^6 ~ 53 MP

And, for the 6×7 format:

R = (4 × 70^2 × 60 × 70)/10^6 ~ 82 MP

A typical digital back such as the 65 MP Phase One P65+ will resolve about 45 MP.

Large-format film

Turning to 4×5 film, the formula gives a resolution of

R = (4 × 70^2 × 100 × 125)/10^6 ~ 245 MP



Not the whole story...

Lens diffraction and depth of field
We need our photographs from the various formats to appear identical if we are to compare them: this means the same view and the same depth of field. A ‘standard’ (i.e. equivalent to the 50 mm lens used with the 35 mm format) medium-format lens is 80 mm – call it twice the focal length, for convenience. The 150 mm ‘standard’ lens used for large format is three times longer. The depth of field for medium and large format to match that of a 50 mm lens is obtained by multiplying the aperture by the relative increase in the focal length. If we assume the optimum aperture for resolution of f/5.6 for 35 mm film, then the medium- and large-format apertures giving an equivalent depth of field are

2 × f5.6 = f/11 (medium format)
3 × f/5.6 = f/16 (large format)

How does this affect resolution? Lens resolution changes with aperture, being at its optimum at f/5.6 for many lenses. The resolution will fall by 25% at f/11, 35% at f/16 and 50% at f/22 (e.g. see the lens reviews at DPReview). So, the resolution of 4×5 film used at a real-world aperture can thus be as low as ~ 175 MP.

Taking depth of field into account, our film resolutions become

R = 17 MP (35 mm)
R = 53 × 0.75 = 40 MP (645)
R = 82 × 0.75 = 62 MP (6×7)
R = 245 × 0.65 = 160 MP (4×5)

Scanning
Scanning film will reduce the resolution further, from manufacturers’ data. A good drum scan will result in a degradation of about 80%, so the above resolution are now


R = 14 MP (35 mm)
R = 42 × 0.75 = 32 MP (645)
R = 66 × 0.75 = 49 MP (6×7)
R = 196 × 0.65 = 127 MP (4×5)

As mentioned above, flat-bed scanners are awful for scanning film, reducing these resolution by half.

Contrast and grain
Digital photographs look sharper than photographic prints because of their greater edge contrast (which is what you enhance when ‘sharpening’ a digital image) and lack of grain. Let’s knock off an arbitrary 5 MP for ISO 100 digital and film images, to account for the ‘cleaner’ look of digital photographs. So, our final resolutions are now

R = 9 MP (35 mm)
R = 27 MP (645)
R = 44 MP (6×7)
R = 122 MP (4×5)

Note: these values should not be compared with manufacturers' sensor resolutions – those simply tell us how many pixels a sensor has, not how much information is recorded, i.e. the true resolution. They need to be compared with sensor resolutions obtained using the Nyquist–Shannon formula. Here are the "true" resolutions of a few digital cameras (the recorded resolution r is obtained from measurements of test charts by DPReview):

21 MP Canon 5D Mk II and Mk III
r = 58 lp/mm
R = 4r^2hw/10^6
R = (4 × 58^2 × 24× 36)/10^6 ~12 MP

18 MP Leica M 240
r = 62 lp/mm
R = (4 × 62^2 × 24× 36)/10^6 ~13 MP

36 MP Nikon D800E
r = 102 lp/mm
R = (4 × 102^2 × 24× 36)/10^6 ~36 MP

(The measured resolution of the Nikon D800E is astonishing, matching the quoted (pixel) resolution of 36 MP, and outresolving DPeview's test chart, which tops out at 83 lp/mm.)

__________________________________________________ _

In summary, full-frame digital cameras of about 20 MP match the resolution of professional 100 ISO colour film scanned on a dedicated film scanner, while cameras using Sony's 36 MP sensor such as the Nikon D800E match the resolution of 645 medium-format film. A 50 MP digital can match 6×7 film, but large-format film still outperforms the best digital camera by a wide margin.
__________________________________________________ _

Printing
Traditional darkroom prints made from film in an enlarger appear significantly less sharp than digital prints from scanned film: first, limitations from the apparatus – the enlarger and paper must be perfectly parallel, and this becomes more critical the larger the print, and that the lens itself degrades the image; secondly, scans can be made ‘sharper’ by adjusting the edge contrast – which cannot of course be done when printing directly from film.

The sharpest film print is thus digital, despite the loss in resolution from scanning: for best quality, we should scan the film and obtain a C-type or inkjet print – not use an enlarger.

Inkjet prints are slightly sharper and more expensive than C-type prints, but C-types are more robust and are a traditional silver-based photographic medium (if that’s important to you). Also, C-types have a different look to inkjet prints (that's different not better!) – the pigment in C-types sits in the surface, not on the surface, which gives them a subtle depth and three-dimensionality.

So, sharpness vs subtleness of depth – you can only have one!"
__________________

-=Rich=-

Portfolio: www.richcutler.co.uk