Something about lenses

[gus]

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

[DoctorIt]

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
Gusyup. we were talking about this somewhere else recently. the equipment is obviously built pretty well these days, so you don't have to drive yourself crazy worrying about it. You do however have to plan for it. Don't expect to barge into a bldg and start firing away. Unless you like that soft foggy look :D

[gus]

So will white make a difference to shots in high heat or is it a fish type thing & black will do the job fine but you wont look as professional ?

Anyone know of a site that has photos or explains this black v's white thing re temps ?

[wxwax]

I'd look on their websites, see if they specify maximum temps in which you can use the lenses. I wouldn't have thought the white vs black thing would be an issue, but you never know.

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.

[DoctorIt]

I'd look on their websites, see if they specify maximum temps in which you can use the lenses. I wouldn't have thought the white vs black thing would be an issue, but you never know.

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.if your sunglasses fog up, that's condensation.

white vs. black is just a recognition thing. there is no science behind it, at least I seriously doubt it.

[mercphoto]

if your sunglasses fog up, that's condensation.

white vs. black is just a recognition thing. there is no science behind it, at least I seriously doubt it.

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. :) I don't know if its actually true or urban legend.

[DoctorIt]

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. :) I don't know if its actually true or urban legend.I'm just a stupid engineer, but I'd be willing to bet that the thermal expansivity of ANY glass is orders of magnitude less than ANY thermoplastic, regardless of color.

I'd say: nifty urban legend

[cmr164]

I'd look on their websites, see if they specify maximum temps in which you can use the lenses. I wouldn't have thought the white vs black thing would be an issue, but you never know.

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.
Be a believer... going from aircon to outside

http://www.iisc.com/BK_WEDDING/14/images/IH9T3971.jpg

Trying to be creative with it another day...

http://www.iisc.com/BK_WEDDING/15/images/IH9T4086.jpg

[pathfinder]

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. :) I don't know if its actually true or urban legend.


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.

[fish]

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

[DoctorIt]

dang, you had to go bringin' up the astronomers didn't you!

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).

[gus]

Thanks everyone but you all missed my question entirely. Its obvious why they are white. I have a light coloured car for that very reason buuuut....

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.

[fish]

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 ?
Do you need to know, or just simply want to know? :D


Do you notice the affect of a UV filter over your lens? It would be that subtle, I think.

[gus]

Do you need to know, or just simply want to know? :D


Do you notice the affect of a UV filter over your lens? It would be that subtle, I think.
I def need to know...i could see a very very expensive mistake about to happen here if i get this wrong.

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"

[DoctorIt]

Thanks everyone but you all missed my question entirely. Its obvious why they are white. I have a light coloured car for that very reason buuuut....

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.i really really doubt it. don't get L glass just because you think it will work better in heat.

that being said, if you have a chance to get L glass, do it!!! :D

[pathfinder]

I def need to know...i could see a very very expensive mistake about to happen here if i get this wrong.

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"


'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.

[gus]

Thanks as usual doc & PF for the input...i have to start to narrow this down somehow. I was not considering L glas as i am looking at Nikon & i read that Nikon were now producing white also.

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.

[Andy]

Thanks as usual doc & PF for the input...i have to start to narrow this down somehow. I was not considering L glas as i am looking at Nikon & i read that Nikon were now producing white also.

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!

[ian408]

I'm just a stupid engineer, but I'd be willing to bet that the thermal expansivity of ANY glass is orders of magnitude less than ANY thermoplastic, regardless of color.

I'd say: nifty urban legend
I'd say this is something we need to run past Myth Busters :rofl

[gus]

I'd say this is something we need to run past Myth Busters :roflWhat a top show...just stared getting it here. Saw the JATO/Chevy one & the pop rock cany the other night. He really has to lose the mostashe [sp] though.

[ian408]

What a top show...just stared getting it here. Saw the JATO/Chevy one & the pop rock cany the other night. He really has to lose the mostashe [sp] though.
I watched it one night and recognize the place they work out of as well as a
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 :rofl

Ian

[gus]

Sorry for all the questions guys. I know they sound basic but i have to get the picture clear on the subject & like opinions on this board

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 ?

[cmr164]

Sorry for all the questions guys. I know they sound basic but i have to get the picture clear on the subject & like opinions on this board

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 ?
What the 2.8 gives you is the possibility of 1/1000 when the f4.0 can only do 1/500. It will give you just a bit more ability to use DoF to single out one vehicle in a group. A final point is that the 2.8 lens closed down 2 stops to f5.6 is possibly slightly better optics than the f4.0 stopped down only one stop to the same f5.6.

Hope this helps

[gus]

What the 2.8 gives you is the possibility of 1/1000 when the f4.0 can only do 1/500. It will give you just a bit more ability to use DoF to single out one vehicle in a group. A final point is that the 2.8 lens closed down 2 stops to f5.6 is possibly slightly better optics than the f4.0 stopped down only one stop to the same f5.6.

Hope this helps
Thanks cmr...this 1/1000..1/500 would not matter in good sunlight though would it ?

[cmr164]

Thanks cmr...this 1/1000..1/500 would not matter in good sunlight though would it ?
Overcast day, could make a difference. An extra f-stop gives you a 2 times faster shutter when you need it. Even in bright sunlight 1/1000 might not be fast enough.

http://www.iisc.com/dgrin/nhis_060_roll_s.jpg

[gus]

Overcast day, could make a difference. An extra f-stop gives you a 2 times faster shutter when you need it. Even in bright sunlight 1/1000 might not be fast enough.

ahhh the penny drops. Thanks heaps charles :thumb

& if thats your shot...what is the lens ?

[GREAPER]

By my elementary school math (so take with a grain) a baseball thrown at 90 mph will travel 1' 3" give or take in 1/1000th of a sec. so at 1/500th it will travel 2' 6"

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.

[cmr164]

By my elementary school math (so take with a grain) a baseball thrown at 90 mph will travel 1' 3" give or take in 1/1000th of a sec. so at 1/500th it will travel 2' 6"

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.
You might want to run the math again:

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. :)

... if thats your shot...what is the lens ?
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

[pathfinder]

ahhh the penny drops. Thanks heaps charles :thumb

& if thats your shot...what is the lens ?


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.

[gus]

Im savouring it all gents...helping me out lots here.

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 ?

[Seamus]

Im savouring it all gents...helping me out lots here.

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.

[gus]

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.Your hitting the 'glass' nerve now shay.

Surfing photography would be something i have considered out of my reach shay. You have to photograph your enviroment & we have a lot of surf here.

What is the trade off for using the 2x converter ? There must be some quality loss i expect.

Would the bigma at f4-6.3 do an adequit job on a distant surfer in direct morning sun ? I know thats an open type question but im so lost with this "what will work in what light" biz

[gus]

I found this on the web...so even at 1000mm its a long slow reach isnt it ?



"Pro surfer at Snapper Rocks"
Photographer: David Magahy
Canon EOS 1D
500 f/4 Lens + 2x Extender
1/400 sec @ f/11 ISO 200 +1/3 exposure

[wxwax]

I've used a 1.4 and 2x converter on a 300 f4 lens. I'm told I lose a stop with the 1.4, and it had a big impact on the autofocus. I couldn't use it for an American Football game under cloudy conditions - the autofocus was just too slow. Image quality was OK. I read that the 1.4 works much better on a faster lens, like the 300 2.8. $$$$$$$

I was extremely disappointed with the 2x on the same 300 f4. Very soft images, and again, autofocus was terrible, even on a sunny day. Again, it may be different on a faster lens. This is just my experience.

[gus]

I've used a 1.4 and 2x converter on a 300 f4 lens. I'm told I lose a stop with the 1.4, and it had a big impact on the autofocus. I couldn't use it for an American Football game under cloudy conditions - the autofocus was just too slow. Image quality was OK. I read that the 1.4 works much better on a faster lens, like the 300 2.8. $$$$$$$

I was extremely disappointed with the 2x on the same 300 f4. Very soft images, and again, autofocus was terrible, even on a sunny day. Again, it may be different on a faster lens. This is just my experience.
Thanks waxolious...thats good info for me.

[cmr164]

Your hitting the 'glass' nerve now shay.

Surfing photography would be something i have considered out of my reach shay. You have to photograph your enviroment & we have a lot of surf here.

What is the trade off for using the 2x converter ? There must be some quality loss i expect.

Would the bigma at f4-6.3 do an adequit job on a distant surfer in direct morning sun ? I know thats an open type question but im so lost with this "what will work in what light" biz First off the price benefit is clear to go with non-OEM brands like sigma, but the optical quality and construction quality are not as good. Are they good enough? Look around read some reviews. Is the sigma f2.8 with a 2x converter a good idea. IMHO not very often. If you want a 400mm f5.6 lens then Canon makes one and it is not that expensive. For me things that matter in this equation include having IS on the Canon 70-200 2.8L. Is IS worth it, well here is a handheld shot that I took using the IS on the 100-400L mounted on an old 2MP (yes 2mp) dslr without even anything to lean on. (yes a tripod would have been better: not the point)

http://www.iisc.com/dgrin/moorea_moon_cropped.jpg

Aside from IS there is the issue of Sigma's reverse engineering. You have to admire the work that they do but it is not perfect and sometimes Sigma lenses just do not work when going to a new Canon camera and have to be rechipped (http://www.google.com/search?q=sigma+rechip). Another area where the Canon glass and partcularly the 'L' glass blows away Sigma is in the speed and accuracy of the AF. If you are going to be doing action photography that might be a biggie.

Sigma makes fine lenses at a very good price but for me the cumulative issues rule them out. For you it might be different. As for extenders... I just bought a 1.4x extender and it is OK, not wonderful, but not terrible. The 1.4x only kills 1 f-stop and preserves AF with all my lenses. I am not likely to buy a 2x and am not enamored with the 2 f-stop loss, the crippling of AF for some lens combos and the additional degradation in contrast.

Read through this FredMiranda thread (http://www.fredmiranda.com/forum/topic/168754/0) from start to finish to get both the rational and irrational takes.

[wxwax]

Good stuff, Charles, thanks.

[Harryb]

Sigma makes fine lenses at a very good price but for me the cumulative issues rule them out. For you it might be different. As for extenders... I just bought a 1.4x extender and it is OK not wonderful but not terrible. The 1.4x only kills 1 f-stop and preserves AF with all my lenese. I am not likely to buy a 2x and am not enamored with the 2 f-stop loss, the crippling of AF for some lens combos and the additional degradation in contrast.

Read through this FredMiranda thread (http://www.fredmiranda.com/forum/topic/168754/0) from start to finish to get both the rational and irrational takes.[/QUOTE]
I agree that if you want the best of the best glass you go with Nikon 2.8 glass or Canon 'L' glass. They are sweet lenses and can't be beat. Having said that one also has to take a reality check. I just bought the Nikon 300mm/f4 lens. I really wanted the Nikon 300mm/2,8 lens. The problem was that the 2.8 lens cost $3995 and the 4.0 lens cost $1160. Also the 2.8 weighs 5.7 lbs as opposed to the 4.0 which weighs 3.1 lbs.

I wanted to get the Nikon 70-200/2.8 VR lens but it cost $1600 so I got the Sigma 70-200/2.8 and the 1.4 and 2.0 tcs on e-bay for $700.

Both my Sigma 70-200 and my Nikon 300mm/f4 are fine lenses. Sharp and with good contrast as some of the pics I've posted show. Are there better lenses out there, of course. The problem is that when I buy a lens I have to deal with some economic realities.

Harry

[Michiel de Brieder]

My next purchase for tele will definitely be the Bigma! I've seen a lot of stunning pics of birds lately... and the 20D is capable of very useable ISO 1600 photos. I think it will be very good for action (I've used the 20D + 70-200 F/4 and 1.4 TC @ ISO 100 for some action, if I had bumped the ISO I would have had some killer shots!)
So, while I currently have only Canon gear, my next purchase will be a Sigma, but that will take a lot of months, because I've gotta save some for my Yosemite trip :D

[pathfinder]

I've used a 1.4 and 2x converter on a 300 f4 lens. I'm told I lose a stop with the 1.4, and it had a big impact on the autofocus. I couldn't use it for an American Football game under cloudy conditions - the autofocus was just too slow. Image quality was OK. I read that the 1.4 works much better on a faster lens, like the 300 2.8. $$$$$$$

I was extremely disappointed with the 2x on the same 300 f4. Very soft images, and again, autofocus was terrible, even on a sunny day. Again, it may be different on a faster lens. This is just my experience.


Waxy - The 2x Teleconverter costs you 2 f stops of light - That drops your 300 F4 to a 3oo f8. Most Canon SLRs do not autofocus with lenses slower than F5.6 The 1 series cameras 1D, 1DMkll, 1Ds, 1Ds Mkll will autofocus with the center AF point I believe at f8 for horizontal lines - not sure about the ability at f8 with vertical lines. That is why you had trouble under cloudy conditions. And that is why some shooters prefer the F2.8 lenses to the F4.

300mm F2.8 with a 2x becomes and f5.6 and will still autofocus but more slowly.

[Andy]

if i can't get it with my 70-200L f/2.8 i.s., well then, it's not meant to be... at least for this boy.

when i go to one of andy biggs' safaris (http://www.andybiggs.com) i will definitely buy or rent a 600mm L or some such big beast.

[ian408]

if i can't get it with my 70-200L f/2.8 i.s., well then, it's not meant to be... at least for this boy.

when i go to one of andy biggs' safaris (http://www.andybiggs.com) i will definitely buy or rent a 600mm L or some such big beast.
Carting around a big lens is a pain :D Not just because it's heavy but
because, at least at the public places, you get a lot of questions that
detract from shooting time. On the down side, I was thinking of how it
would be perceived in the scope of Rutt's recent incident.

But the coolest thing did happen yesterday. I wanted to find out whether
the behavior of egret was "normal". Not only is it normal but they don't see
it all to often and the pix were a big help to them with regard to identifying
what the bird ate (only because the salt marsh mice are endangered).

ian

[Seamus]

Your hitting the 'glass' nerve now shay.

Surfing photography would be something i have considered out of my reach shay. You have to photograph your enviroment & we have a lot of surf here.

What is the trade off for using the 2x converter ? There must be some quality loss i expect.

Would the bigma at f4-6.3 do an adequit job on a distant surfer in direct morning sun ? I know thats an open type question but im so lost with this "what will work in what light" biz
I don't have a Bigma but I have seen some great surf shots taken with it.

http://photography-on-the.net/forum/ has an excellent sports section. Search it for views on the Bigma. One of the reviews of the bigma on FM was by a professional photographer who covers the uspga. He had to buy a bigma to replace a lens which he had left at home. The lens allowed him to cover the tournament. It wasn't as good as his 500L or 600L but it didn't cost $3,000+.

the sigma 1/4x and 2x converters don't work properly with the bigma. They don't autofocus with this lens. The 70-200 and the 120-300 are the only lens that will autofocus with the extenders afaik. The 2x converter with my 70-200 gives me 5.6 at 400. The autofocus works and it was a lot cheaper than a 70-200 lens + a 100-400 lens. I don't know anything about shooting surf shots unfortunately but most of the good shots I have seen have the surfer close to shore as the wave is breaking.

Imho the big advantage the D70 has over the rebel is the kit lens that is included. From what I have read the Nikon 18-70 is an excellent lens and is far superior to the 18-55 lens that Canon ship with the rebel.

You can cover most general photos from landscape to portraits with this lens. You can save your money and put it towards a big zoom lens if you want to shoot surf or motorsports. You enjoy sunny weather in oz, the "slow" f4 lens won't be a handicap.

I'm not sponsored by Sigma but I don't feel that a $3,000 lens is necessary to take great shots. If money is no object buy the best but if, like most people, you are on a budget do read the reviews on these forums and consider them. If you hate the lens you will be able to sell it without too much of a loss and it won't have cost you (relatively) that much in the first place or ideally you could rent the lens and try it out before you buy it.

Again just my 2c worth.

[gus]

This is great stuff...im reading everyones posts..thankyou all very much.

This auto focus you all mention...how can a telephoto lens auto focus over that distance ? Shay if i was to aim aim that Sigma 50-500 at a distant surfer in strong sun ...it sees it & will auto focus ?

I understand how my little olympus does it (red light shoots out) but cant see how a large tele can do it on a smallish subject & not want to lock on to the background.

[Michiel de Brieder]

The camera determines the distance to focus to (meaning: the object it should focus on) and does so using contrast. the more contrast there is, the easier it is for the AF to work.
So, are you getting somewhere towards deciding yet? :bad

[ian408]

... and does so using contrast. the more contrast there is, the easier it is for the AF to work.
This statement pretty much cuts to the quick.

Ian

[gus]

The camera determines the distance to focus to (meaning: the object it should focus on) and does so using contrast. the more contrast there is, the easier it is for the AF to work.
So, are you getting somewhere towards deciding yet? :badThanks Michiel...i had been wondering that for quite some time.

deciding ...huh...no way. But man im having fun researching it all on the net.

[Seamus]

http://photographyreview.com/pscLenses/35mm,Zoom/PLS_3128crx.aspx


Another site with lens reviews.

[gus]

http://photographyreview.com/pscLenses/35mm,Zoom/PLS_3128crx.aspx


Another site with lens reviews.
Ta shay..that site with the surf on it is great & this review also.

Very much apresheea...appriseat...its good :thumb