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Messages - dr croubie

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1306
Lenses / Re: EF Lens Adaptor for iPhone 3 & 4!
« on: July 07, 2011, 10:29:27 PM »
maybe it's just me, but that whole thing of 'being cool' because you have the latest and greatest shiny gadget that you don't actually need (or even worse, thinking you need it and that it enhances your life, doesn't waste your time, and you can't live without it) is precisely why i Don't have an iphone (or any other tablet).

My nokia 8310 is 9 years old. it still works. it makes calls, it sends and receives sms.

ie, it's a phone.

1307
Software & Accessories / Re: Graduated Neutral Density
« on: July 07, 2011, 10:19:01 PM »
I was asking myself that question earlier in my head after reading a different thread on Cokins and holders.

one thing that i thought of is that if your sky is really bright, and your subject is really dark, you can either:
- expose the sky to just below full-blowout, and boost the brightness of the dark bits in Post Processing (less detail though).
- expose the dark bits nicely, but once the sky's blown out to full white, no PP can get any detail back.
- bracket exposures and combine them in PP (never done it, but i presume it'll take a bit of time)
- grad-nd will expose the dark bits nicely, stop the sky from blowing out, but my guess is that it works best only on straight-line horizons? what if you've got a mountain peak or two?

1308
Software & Accessories / Re: [ASK] Step up ring recomendation??
« on: July 07, 2011, 10:14:26 PM »
Quick question for neuro and or anyone who has the my lens and can answer... I believe neuro said in some post somewhere back he has/had a 70-200 F4 IS... Has he or anyone else use this lens, with a step up ring to 77mm for a polarizer or whatever filter had any problems with the hood? I have that lens and the hood shoots out a little bit width wise which seems like it would accommodate it, however, it is a longer circular hood so adjusting lets say a polarizing filter with such a hood on would be cumbersome... any experience with this lens and filters or this lens and step up rings and filters and the hood?  Any thoughts from those who have this lens would be welcomed.  =)


I don't have the 70-200, but i have the 70-300L, and i'm guessing that the designs would be the same.
If the hood reverses to go over the body and shoots out wider straight away, it looks possible. actually, just looking at the TDP Compare Tool, the hood shoots out even wider sooner.

But you want to put a 77mm on a 67mm thread, so now i'm not so sure. if you've got the lens, first thing to try is whether you can get the 77mm filter to touch the lens without jamming on the hood (you can even do it with the hood and filter, without the lens). my 72mm filter goes all the way up the hood (doen't that sound dirty?) of the 70-300L, so i'm guessing it'll easily work with the stepring (which i must buy on ebay today, didn't get there yesterday).

my plan for a way of controlling it is with magnets. firstly, the hood is plastic, so it won't interfere. I've got a tiny (2*2*1mm) super-magnet (neodymium?) which i'll glue to the edge of the CPL (it won't stick if the cpl is brass/alu). I've got a bit bigger magnet for the outside, which will attract the smaller one inside and when i move the outer one the smaller one will drag the ring around with it. (i plan to add some kind of cloth covering or fluff to the magnet outside the hood so as to not scratch the hood).

whether this works will depend on if the magnets are strong enough to attract each other through the distance to outside the hood, and if i can glue the smaller magnet to the CPL without gluing it to its holder and stop it spinning around at all.

if it works (trying it as soon as i get my step ring delivered) i'll post photos.

1309
Lenses / Re: Dust on EFS 17-55 f/2.8
« on: July 07, 2011, 09:55:40 PM »
here is the extreme way to clean if you're that paranoid about dust.

best thing to remember is that dust on front element is not bad. dust on rear element is worse, and dust on sensor is worst.

I've got some ~50 year or Takumars of my mum's, they're just primes with the 'move every element together' to focus. Even they've got dust inside, between the elements.


whoever said about the people whining because they paid L-money and got a non-sealed lens, i'd say that's the point. How many Joe Consumers with 18-55 Lenses actually complain about dust in their lens? i'd guess there's just as much getting in, but they're not so fussy as someone who'd buy a 17-55... (and even if they did care, it's only $50 to buy a new lens, cheaper than cleaning it professionally)

1310
Lenses / Re: EF Lens Adaptor for iPhone 3 & 4!
« on: July 07, 2011, 09:48:19 PM »
Pricing is surprisingly good, have you seen what some Nikon to EF adaptors cost? That's just a piece of machined aluminum.

This is a fun product, and we need fun products.


$9?

I'll definitely agree on the 'fun product' statement. i try to go as 'non-standard' as i can.
(there's nothing like extension tubes, ef-pentaconsix adapter, two 2x teleconverters, more tubes, reversal adapter, pinhole, with a circular polariser on the end, all stuck to a 7D...) when the 10 minute exposure is up i'll let you know how the picture turned out :P

i'm certainly glad things like this exist, but i wouldn't buy one (and god help me as soon as someone says they get good IQ out of it)

1311
Lenses / Re: EF Lens Adaptor for iPhone 3 & 4!
« on: July 07, 2011, 09:12:40 PM »
*checks calendar*

ok, it's not the first day of april...


so just a guess, manual focus only and no power for the IS? good luck birding with an 800mm then. (or does the adapter have batteries to power the IS? if not, why not? *wanders off to patent office*).

i can't imagine the iphone camera will out-resolve a 3rd-hand 1000D, i tell you which i'd rather spend my money on too.

1312
Canon General / Re: Tilt shift lens help
« on: July 07, 2011, 09:42:10 AM »
I've not used the official canon-types, but i've dabbled with adding Medium Format lenses to my system using a tilt adapter. The metering is way off on them most of the time, i've always wondered if that happens to the 'real' TS-E types too.

Best i can suggest is:
- Live view metering tends to be more accurate under most conditions.
- Or if you use the viewfinder, the metering (in my experience) will always be the same number of stops over/under as long as the tilt stays the same (never used shift), if you recompose or refocus you're fine.
- Live view focussing is your friend, especially when using tilt.
- If you're using a TS-E you're hardly going to be catching action, you're forced to take your time, tripod and at least a few minutes to compose. Just take a few more shots, take them again if they're way off.
- Exposure bracketing is your friend!

1313
Canon General / Re: Canon 3 Layer Sensor (Foveon Type?) Patent
« on: July 07, 2011, 05:16:35 AM »
Sigma sD1 has richer colors because of the independent layers.

maybe true, maybe not. unfortunately that's always going to be an apples vs bananas argument. lenses affect contrast, black/brass/silver aperture blades, coatings, even lens hoods do a bit too. so does the image processor it's attached to, and will most likely be tuned to whatever sensor type it's connected to.
try comparing 2 different car engines for performance, after they've been built in 2 different types of car with different chassis, wheels, suspension etc, and driving it around a track. you can infer which engine is better, but you'll never get an exact comparison. (sorry for the car analogy, top gear is on in the background).

One thing i've just noticed with the patent, compared to the X3 sensor (at least according to wikipedia): the canon patent specifically says that the blue is widest, then green, then red. the diagram of the X3 on wikipedia may be a simplification, but it looks like the colours are all the same width.


aside: a patent has to contain something new and/or innovative compared to another patent. maybe the width-difference is what canon is trying to set apart from the X3?

aside from the aside: these patents were (probably) written in Japanese, yes? can we get the original japanese patent and an electrical engineer who can read japnese from somewhere? anyone know anyone? these patents really are hard to decipher most of the time...

I wonder why they (Sigma) call it (SD1) 46Mp camera, because actually it produces 46/3~=15Mp pictures.

one word: marketing.

it *should* be called a 15mp picture, because that's how many dots you get at the end of the day. they've got 15m red, 15m blue, 15m green sensors, but on 15m unique spots.
but then a canon 15mp sensor has 5m blue, 5m green, 5m red sensors on 15m unique spots (with 15m lenses on top). one dot only takes one colour, and the processor guesses the values of other colours from the neighbour. so at the end of the day you get 15m dots. but the colour of those dots is only 1/3 definitely accurate, the other 2/3 are guess or interpolated.

(hmmm, by the same logic, my monitor is 1680*1050 pixels (1.7mp). but it actually has 1.7m red, 1.7m blue, 1.7m green on 5.3m unique sites. should i call my monitor 5040*1050?)

1314
Software & Accessories / Re: [ASK] Step up ring recomendation??
« on: July 07, 2011, 03:16:00 AM »
I'm a big fan of rings, and i just bought randomly off ebay. I'm just about to go there again and buy another lot soon too.
I bought in 2 or 3 lots, a few each time to combine postage, and i ended up with:

S&W - a bit more expensive than the cheapest, but i bought them all from one guy and paid the same postage as one ring, so ended out cheaper all up. The best thing about them is they come with a nice soft plastic pouch-envelope thing (i know i'm not describing it the best, want a photo?) that i've ended up using to keep my filters and pinholes in.

Sonia? i think it says - the step down on these are cut all along the sides vertically for extra grip, the step up have a diagonal bit chamfered off the top for grip. all my other brands are silky smooth on the outside, so less grip to get them apart (by the same token: less grip to force them stuck together). came in a throwaway paper box, so now jangle loose in my bag (but mostly i keep them stored on lenses or together in a stack anyway).

Kood - think it was more expensive again, only got one, but it was the only brand that made a certain size i wanted.

noname brand - no idea, was dirt cheap and chinese i think. still, nothing wrong with it.


all of them together, i've never had a problem. Even if i thought in the past i've stuck them irreversibly together, the next time i try they just come apart. each brand to each other or between brands.
no brand can shield you from that 100%, but taking care of them will. never force anything, stop and take a deep breath before you break anything.
There are differences between brass/aluminium/steel, but you never know what you're getting even if they do state it on their ad, i can't remember which one is meant to be better anyway. just make sure they're black, i've seen steel-polished ones and that's just asking for ghosting...

1315
Canon EF Prime Lenses / Re: Canon EF 100mm f/2.8L Macro IS USM
« on: July 07, 2011, 12:30:15 AM »
I spent half an hour this morning hunting bees in flowers in my backyard, 70-300L on a bunch of extension tubes. MF only, stupidly low DOF, handheld, only thing useful was the IS, those bees move fast and you have to be lightning quick to find, follow, frame, focus before it moves to the next flower.

sigh.

damn i want the 100L, would make my life so much easier...


ps, Tian, i love that apple-globe. Extra points if you managed to bite it that way rather than use a knife. (did you put the mid-Atlantic ridge there on purpose? not in exactly the right spot, but extra points anyway)

1316
Canon General / Re: Canon 3 Layer Sensor (Foveon Type?) Patent
« on: July 06, 2011, 10:06:10 PM »
The text is (as always) mostly unintelligible. and i wish the diagram was a bit larger.

ok, i've changed what i originally thought. It didn't look like a sensor on first inspection, but now i've convinced myself it is.

with the 'Set' FET off, nothing happens.
turn the Set FET on, and one of the TxR/G/B FETs on, and the voltage at the filled-in dot at the right will change proportionally to the voltage at the '101' layer.
Turn that FET off, turn on the next TxRGB FET, and read the voltage .

the line:
"Therefore, in reading the charge of B, it becomes difficult to receive light G, to prevent mixing"
mean that only one colour can be read at a time sequentially. Turning 2 or 3 FETs on at once, the voltage will be proportional to total charge on all 3 combined (added or averaged, not sure).
So you expose your sensor using the shutter, black it off, then read every pixel's colour sequentially before the charge dissipates (switching FETs on and off can be done in the order of nanoseconds).

turn the 'Res' FET on to reset the charges on everything.

1317
Lenses / Re: New lens or body?
« on: July 06, 2011, 09:18:07 PM »
what's an xsi in real numbers? 450D?
ok, it's an older body, and *only* 12 MP. But for what it does, it's great.
you've already got the 'good' kit lens in that it's the IS version.
the 70-300nonL is good for its price (but i personally hated it at 300mm and got the L).

so going from 18-55 to 24-70 you will:
a) future-proof yourself for fullframe.
b) get a big difference in IQ.
c) gain 750g to your kit.
d) lose IS, lose 18-24mm (which will hurt on a crop-body)
e) gain a few stops of light, gain 55-70mm range.

going from 70-300 to 70-200 2.8 i:
a) lose the 200-300mm range.
b) maybe you've got a good copy, maybe i had a bad copy, but i wouldn't miss the 200-300 range because it was too soft to use.
c) if the deal comes with the extender, then you gain the 200-400 f5.6 range instead.
d) go a bit up in IQ in the 70-200 range, and gain 1-2 stops.
e) gain 680g in weight
f) Lose IS? you didn't mention if it was the IS or non-IS version.

going from 450D to 550/600/60/7D, depending on model:
a) definitely gain 50% more MP
b) maybe better AF system
c) maybe bendy screen
d) maybe more FPS
e) definitely video




So, if you upgrade the wide lens, you still have to swap to the 18-55 for the widest shots, or get a 10-22 and stick with APS-C. If you can put up with swapping lenses for a while (up to a year or two?) then upgrade to 5D3, go that.
If you're always going to be 7D or less, ie APS-C, then you'll definitely want to pair a 24-70 with a 10-22 (or equivalent 3rd-party). Or consider another option, 17-55 2.8 or 15-85 (choose between these on zoom range vs low-light only, hardly any IQ diff).

If you upgrade the zoom lens, and go the 70-200 + extender, take it out in the field if you can first (or rent one?), see how many shots you miss because you were too busy putting the extender on to get that extra reach. if it's the non-IS, see how much that affects your shooting style. see how much better the photos are wide-open at f/2.8. Also consider the 100-400 as AJ said, or a bit cheaper now is the 70-300L, better IQ than a 70-200+tc (how much better depends which flavour 70-200), no changing TCs, if you can put up with the f/5.6 for extra reach or convenience.

if you go the body option, one thing to think about:
the xxxD models are upgraded every year on the dot. they'll take the latest sensor whatever it is. if the 7D2 comes out soon, and at least 6 months before the 650D, then the 650D will get that sensor.
(it might not, but it has happened every time until now. even the 400d got the sensor *before* the 40d, the 50d sensor went to the 500d 6 months later, and the 7d sensor went to 550d 6 months later).
you can wait on a body, but every time there'll be something new or cheaper just around the corner to wait for. bodies degrade in price a bit more than good glass does too. if you're buying a used 70-200 2.8 nonIS, then factor in that if you ever need to sell it, and treat it well, you can probably get back almost what you paid for it. not so with a body.


hmmm, i came here thinking that the obvious answer was to go the 24-70, but i'm not so sure now.
i think the biggest question you need to answer first, is are you going to be definitely going FF at some point. the 5D2 will always be a good camera, regardless of if/when the 5D3 comes out. my bet is the 5D3 will be 50% more than 5D2's price now on release, a used 5D2 will hold its value for a while until 5D3 stocks are ubiquitous, i might even consider one at that point. upgrading the wide makes no sense if you're staying with APS-C, or get an APS-C wide (17-55, 15-85). So my money's actually on going the long-upgrade (also consider the 100-400 or the 70-300L), then if you ever go FF you'll have to get a wide-angle FF lens at that point too...

and i didn't give any good arguement as to why not to upgrade the body. my feeling is that the new models are coming out *soon*. but 12 MP is more than enough unless you're doing enlargements, or plan to crop out smaller bits when your lens can't reach far enough (i do sometimes). I'd stick with 450 until 7d2 or 5d3 some out, then maybe even a 2nd-hand 7d or 5d2 will be very attractive once the price has settled, a newer model doesn't make the old model any worse than it is now...

1318
Lenses / Re: Canon 400mm L 5.6 .. So what's changed in 19 years?
« on: July 06, 2011, 08:36:35 PM »
...and don't forget that sensor shift has problems with overheating, but we've heard that story before...

also, don't forget The Third Option, if only canon would make something like that.
but they won't, because then people would buy the 70-200 nonIS and the converter for less than the price of the 70-200IS (if it worked as good, that is). I'd even buy one for all my old MF primes, if it worked half as good as a canon IS, just for framing...

1319
Lenses / Re: Canon 400mm L 5.6 .. So what's changed in 19 years?
« on: July 06, 2011, 10:31:30 AM »
cause nobody who has tested the "IS" in other lenses do not have any interest in non-is lenses

google translate issues aside, i can definitely agree.
a 250 f/3.5 MF prime i've got is just hand-holdable focussable, despite its soviet-stiffness in the ring. add a 2x tele for 500 f/7 and i can barely frame and focus, lack of a tripod ring and gimball head doesn't help. I could maybe put up with 400 f/5.6 without IS, but it'd have to be some damn sweet IQ to make up for the annoyance.

(and if i add my two 2x teles for 1000mm f14, just breathing on the lens to focus will shoot the framing off, so not very useful even in studio work, but it sure looks impressive with all my extension tubes)

1320
Software & Accessories / Re: Filters - Screw on or not ?
« on: July 06, 2011, 10:07:21 AM »
I'm another screw-in user, and i've got the whole range of step up
21-37-52-58-62-72-82 and back down again, for everything from pinhole, lensbaby, niftyfifty, efs15-85 to 250mm f/3.5 Medium Format.
I've only got 2 CPLs, 72 & 58mm to match my efs 15-85 and 70-300nonL at the time (which i've since sold), with all the rings i can use them on any lens, and the rings cost less combined than the 58mm CPL did.

I've checked for size, but haven't bought the ring yet, that i can mount the 72mm CPL via a step ring on my 70-300L with the hood on, but i've also confirmed that i have to screw the step-ring onto the lens *after* putting the hood on, and will have to unscrew it before removing the hood to reverse it for the bag.


sometimes, it does get annoying the time it takes to screw/unscrew filters, last time i was at a zoo i just left the CPL on the whole time, didn't even take it off to go inside, just put up with the loss of light for a few shots (which were only memories, not portraits for enlargement).
but then, i've never used the cokin, can't comment on the time it takes for them, but probably just as long or worse. i'd be heading for cpl (i know you said you don't use them though) and ND in screw-in plus rings, the cokin-for-grad-nd arguement makes a bit of sense, i'll keep in mind i'll have to buy into that system if i ever want to go for them...

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