Something about lenses
I can see what this white lens thing is all about re heat reflection. But just how much of an effect does it have. Why im asking is that whilst im out & about scoping for gear (like a junkie needing a fix) ...the least amount of mistakes i make ...the better.
I walk everywhere & seriuosly...it can get over 50c (122f) here in direct sun in minuites. Not every day is like this but in full sun for a few weeks a year..its that hot.
Should i look at these white lenses over black ?
One other question is what happens when i go from this heat to the car in the air-cond or walk into a air-cond building ? I know what happens to my glasses when i go from a commercial freezer to the outside...moisture all over them. Is this temp change something you fella's consider serious enought to avoid.
Ta
Gus
I walk everywhere & seriuosly...it can get over 50c (122f) here in direct sun in minuites. Not every day is like this but in full sun for a few weeks a year..its that hot.
Should i look at these white lenses over black ?
One other question is what happens when i go from this heat to the car in the air-cond or walk into a air-cond building ? I know what happens to my glasses when i go from a commercial freezer to the outside...moisture all over them. Is this temp change something you fella's consider serious enought to avoid.
Ta
Gus
0
Comments
moderator of: The Flea Market [ guidelines ]
Anyone know of a site that has photos or explains this black v's white thing re temps ?
I don't believe extreme heat and air conditioning changes would fog up the lens. Like you, I've experienced it when walking into summer heat from a commercial freezer. But I don't believe that air conditioning is sufficiently old to cause condensation.
Catapultam habeo. Nisi pecuniam omnem mihi dabis, ad caput tuum saxum immane mittam
http://www.mcneel.com/users/jb/foghorn/ill_shut_up.au
white vs. black is just a recognition thing. there is no science behind it, at least I seriously doubt it.
moderator of: The Flea Market [ guidelines ]
The "reason" I was given was that flourite glass elements expand more with temperature changes. White lens housings heat less than black ones. Hence, the flourite elements are happier out in the sun when in a white casing, rather than in a black casing.
Hey, it sounded good when I heard it.
A former sports shooter
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I'd say: nifty urban legend
moderator of: The Flea Market [ guidelines ]
Trying to be creative with it another day...
Operating System Design, Drivers, Software
Villa Del Rio II, Talamban, Pit-os, Cebu, Ph
If you read Canon's description, I think that you will find that ONLY the lenses with Flourite optical elements or UD glass are WHITE. The rest of their L lenses are black with a red ring and the DO lenses are black with a green ring. I am not aware that flourite lenses are used in wide angle designs, but are used in telephotos. I actually don't like the white color of the lenses - it alarms wildlife, animal and human I think. There are camouflage neoprene covers for several of Canon's big teles that can be ordered from the BirdsasArt website.
Astronomers certainly are concerned about the temperature of the mirrors and lenses in their teles. Most high quality astronomical telescopes with apochromatic lens ( color corrected with flourite elements again) are usually white also. SO there may be a grain of truth to what Canon says about their white lenses.??
As Charles demonstrated so well - condensation can definitely occur when going from a cool dry place to a warm humid tropical climate. Hopefully the condensation is just on the exposed front element of the lens and not on the inside elements. One of the touted advantages of Canon's L glass IS better environmental seals, and condensation is probably one of the reasons. I always leave my lens cover on when going from indoors to outside. A UV fliter over the front element can help protect also.
Moderator of the Technique Forum and Finishing School on Dgrin
Canon lenses are reknowned for their performance and optical quality. And no lenses have a better reputation among professional photographers than Canon's L-series lenses. Identifiable by a distinctive red ring around their outer barrel, these lenses use special optical technologies Ultra-low Dispersion UD glass, Super Low Dispersion glass, Fluorite elements, and Aspherical elements to truly push the optical envelope.
L-series telephoto lenses utilize Canon's UD glass to minimize the effect of chromatic aberration, sometimes called color fringing. UD glass provides outstanding contrast and sharpness in lenses like the 70-200 f/2.8L IS and 300mm f/4.0L IS. Even more effective are fluorite elements, used in high-end super-telephoto lenses like the EF 300mm f/2.8L IS and 400mm f/2.8L IS. A single fluorite element has the corrective power of two UD glass elements, which gives these L-series lenses their spectactular performance.
Wide-angle lenses and fast normal focal-length lenses often suffer from another optical problem spherical aberration which causes an overall softening and optical "smearing" of the image. Canon has developed four different manufacturing technologies to produce Aspherical lens elements, which combat this problem. Aspherical optics, which have an extremely precise variable curvature of one or both sides of a lens element, also allow more compact lens designs and permit lighter lenses with fewer elements. Combined with Canon's exclusive multi-coating technology, Super Spectra Coating, and the attention paid to details such as anti-reflective material inside of lens barrels, L-series lenses virtually eliminate internal ghosting and flare.
Many EF telephoto lenses are white, to reduce the amount of internal heat build-up during long shooting in bright sunlight. And the new Image Stabilized super-telephoto L-series lenses add extensive dust-and moisture-resistant seals and gaskets, enabling pros to keep shooting in the worst conditions.
Canon L-series EF lenses are designed and built to meet the needs of the most demanding professional photographers. Their superb optics enable pros and advanced amateurs to have lenses that are the absolute pinnacle of optical performance, and enable lens/speed combinations with professional performance simply not attainable using traditional optical technology.
http://www.usa.canon.com/html/eflenses/technology/lseries.html
"The Edge... there is no honest way to explain it because the only people who really know where it is are the ones who have gone over."-Hunter S.Thompson
so I looked it up.
first, you can figure most polyethylene based thermoplastics have a thermal expansion coefficient of 200... here are some others:
Material Fractional expansion
per degree C x10^-6
Glass, ordinary 9
Glass, pyrex 4
Quartz, fused 0.59
Aluminum 24
Like I said, an order of magnitude. Never mind the fact that expansion aside, most thermoplastics have much lower moduli, so they can take a little expansion no problem. It's basic math though, the glass that astronomers are using is, to use the term again, orders of magnitude larger than what we are using in our cameras, and the level of precision they need compounds it. So to them, thermal expansion is a big deal - as in, micrometers will make a difference of a couple parsecs (or something like that... I'm out of my league there).
moderator of: The Flea Market [ guidelines ]
What i need to know is that does any one have both & notice a marked difference in photo quality on hot days. ie is it a good thing or a load of cods whallop. They seem dearer & is it a rip off ?
I only ask as if i come across one that is in my range & ive got the oxfords in my skyrocket to buy it on the spot...should i grab it or just wait to pay a little less for a black one. Assuming it is the lens i want also.
Do you notice the affect of a UV filter over your lens? It would be that subtle, I think.
"The Edge... there is no honest way to explain it because the only people who really know where it is are the ones who have gone over."-Hunter S.Thompson
Andy : "Gus ... i just love that shot but i see some xyz creeping in there"
PF : "I see it also andy...gus was this a hot day that you saw the UFO"
Gus : "yep...100f+...why do you ask guys?"
Andy : "well mate i wished you had asked in here before you bought as we would have all told you that in those temps you have to have a white lens to drop the temps & get rid of that xyz in the shot...pity..that aliens ass in the window on the right would have been much clearer had you a white lens"
that being said, if you have a chance to get L glass, do it!!!
moderator of: The Flea Market [ guidelines ]
'gus I own several white lenses - not because they are white, not because they tolerate the heat better ( In Indiana right now it is 50 Farhenheit), but because the are built to a much higher optical AND mechanical standard. Not only are the optics the best in the business even shooting wide open at F2.8, but the lens barrels and iris diaphragms will be more robust. You may need to hold a 300f2.8 IS L or a 500 F4 IS L in your hand to appreciate them. They are heavy, they feel massive in the hand. Not flimsy or lightweight. Nikon's pro quality lenses have the same quality.
Canon's IS technology really does account for sharper mages - no doubt about it. Especially with long ( >400mm) lenses.
Moderator of the Technique Forum and Finishing School on Dgrin
This is a long drawn out process for me as i intend to understand fully just what im buying & what i can expect from it.
From what i see...nikon make some nice stuff to rival canon.
'gus, the definitive answer is,
there is no definitive answer. andy biggs shoots his african safaris with white glass. moose petersen shoots with nikkor black.
with a black lens, you won't miss the alien's ass, i promise. remember, you can always wrap yer lens in a snuggie (i'm serious), so...
make your decision as i've been saying all along: image quality (*very* personal and subjective, that whole cmos - ccd difference); lens selection, quality, availability, price, resale-ability; features (crop factor, speed, af speed, cf speed, shot-to-shot speed, high iso performance, durability, weatherproofing etc); feel (very personal and subjective); price.
good luck!
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few of the places they get stuff from.
I'm going with those guys have too much fun...wait 'till you see the one
about skunk remedies
Ian
If you were to look at a 300 mm tele for daytime sports shots (motor racing)...is there really no diff in f4 & f2.8 ?
Is there anyway you can explain to me at what light the f4 will drop of in image clarity & the f2.8 will keep going ?
Hope this helps
Operating System Design, Drivers, Software
Villa Del Rio II, Talamban, Pit-os, Cebu, Ph
Operating System Design, Drivers, Software
Villa Del Rio II, Talamban, Pit-os, Cebu, Ph
& if thats your shot...what is the lens ?
I dont know how fast those bikes you shoot are moving... but if you want to STOP motion on a fast moving object 1 stop can make all the difference. On the other hand, fast glass is much more expensive, thats why many of us compromise and get the best we can afford with hopes of upgrading later.
90*5280 = 475200 ft/hour
60*60*1000 = 3600000 thousanths of seconds in one hour
475200/3600000 = .132 feet traveled in 1/1000 with a 90mph baseball or just over 1.5 inches in the 1/1000 sec.
'Course maybe I made a mistake.
The lens was the 100-400 IS f4-5.6L which has since been sold with an eye toward replacing it with the 70-200 IS f2.8L (done) and a longer fixed focal length lens TBD but maybe the 400 IS f4 DO or the 500 IS f4L. I definitely could have used a faster lens that day
Operating System Design, Drivers, Software
Villa Del Rio II, Talamban, Pit-os, Cebu, Ph
Penny drops is not quite enough. 'gus.
The Canon 300mm f2.8 IS L is USD$ 3900.00
The Canon 300mm F4.0 IS L is USD$1100.00
That extra stop is expensive to buy and expensive to make. The area of the frontal element of the F2.8 has to be twice as large as the F4.0 2X Larger high quality optics cost more than twice as much moolah...... But the F2.8 will allow faster shutter speeds and shallower depth of field just like CMR said. Which is better for you?? Your call, mate!
The 300mm F2.8 IS L has a reputation as one of the finest telephotos in the world in terms of sharpness, but it is not really long glass. That starts at 500mmm F4.0 The 300mm F2.8 IS L CAN be shot wide open and be very sharp - it does not need to be stopped down 2 stops like a cheaper lens to get a sharp image. It is sharp at F2.8.
Moderator of the Technique Forum and Finishing School on Dgrin
So how would these fast f2.8's go with a converter to bring them up to 300-400mm ? There must be a trade off on quality.
I bet your all laughing reading my posts knowing exactly where im going here...a path well beaten 'eh ?
Don't dismiss Sigma and other manufacturers glass. The Sigma 70-200 2.8 is the same price as the 70-200 F4 L. With a 2x adaptor you have a 120-400 for a reasonable price.
For surf shots or motorsports consider the 50-500 "bigma". go to Fred Miranda
http://www.fredmiranda.com/
and read through the review section and do a search in the forums, particularly the sports and wildlife sections.
Afaik the kit lens with the D70 is a very good lens with a good range 18-70 f3.5. Buy a Bigma or a 70-200 + converter and you have 18-400 / 500 covered for a (in the dslr world) reasonable amount of money.
Just my 2c worth.
Shay.
Ps. I have the canon kit lens , 18-55 + sigma 70-200 & 2x converter.