james_gu

I finally got my lens back from Canon after a month-long wait. They say they

could not reproduce the problem, and sent it back to me. However, the problem

still persists!<br>

<br>

For those who may not know or have forgotten, <a href =

"http://www.photo.net/bboard/q-and-a-fetch-msg?msg_id=00PISZ">here is the original

post that I made. </a><br>

<br>

The problem is as follows: when and ONLY when set at 105mm and f/6.3, the lens

acts sporadically. When pressing the DOF preview button repeatedly, the aperture

diaphragm closes down inconsistently - once big (about f/4.5, by the looks), and

once small (f/6.3) - this pattern alternates, and I can hear the jerky noise the

diaphragm makes. If the diaphragm stops at f/6.3 the last time I pressed the DOV

preview button, then successive shots taken would have the first shot fouling

with over exposure (the following ones are fine).<br>

<br>

I have a 30D, and have tested the lens on a friend's 20D, observing the same

problem, and all my other lenses work fine. So there is no problem with the

camera. This leaves me to wonder: is this a specific issue with my lens or does

it apply to the EF24-105 & 20D/30D combination? What makes me think that this

may be a compatibility/communication issue is that Canon service centre can't

reproduce the symptoms, and the fact that there is a pattern in the fouling

aperture.<br>

<br>

Would the kind photographers with the EF24-105 + 20D/30D combination please

check to see if you experience the same phenomenon? (105mm f/6.3, repeatedly

pressing the DOF preview button would make the problem more obvious).<br>

<br>

Thank you very much in advance for your time.<br>

<br>

James

I agree with Jeff. After seeing some of your photographs, I can say that they are very good.

I'm not going to talk about the 30mm too much as everyone above has already answered. It may be time for your to venture out a little into the wide angle arena with a 10-22. You have great landscape opportunities, and may enjoy the wider perspective of all things. It's more challenging to shoot, however.

This may be ridiculous, but this sounds like my 10 year old MS optical mouse: the right button works intermittently. I think there may be a piece of dust stuck in the microswitch.

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<br>

What you could do is use a remote shutter release (if you don't have one, you can order one for cheap, like <a href = "http://www.dealextreme.com/details.dx/sku.8231">this one</a>), and see if the shutter works or not. If it works just fine, that would suggest a very likely problem with the microswitch. Take it to a service centre, it shouldn't be much of a big problem I suppose.

<br>

<br>

p.s. I have that shutter release works splendidly with my 30D.

Wow! Kathy, can I be your friend? :D

Why not try a Tokina 12-24? Although it is not as wide as the Canon 10-22 or the Sigma 10-20, it does work for a full frame camera, should your friend decide to upgrade later on. It's about $500. (Can anyone confirm?)

Excellent thread! I'm about to take a trip to Europe, so this is very relevant for me.

Sheldon, since home-owner's policy does not cover belongings that are taken out of the house to another country, I will very likely need a separate insurance. In your experience, would it be any more beneficial to get one from the same insurer of the house or car than from another company?

Could someone recommend an insurance company in Toronto, Canada?

Thanks in advance.

<i>"I have no option ..." You have the option to do it yourself and save time and money.</i>

<br>

<br>

pssst...the Canon service centre here (in Mississauga, ON) does it for free, but they don't advertise it ;)

<br>

But it's such a hassle sending it in and having to wait for weeks at a time.

<br>

<br>

By the way, I think I've read somewhere about a camera that generates a positive pressure in the body with fine filtered air. Does anyone know what I'm talking about or was that a dream I had?

Your EF-S 18-55 is a fairly good every day general purpose lens. I may be misreading, but from your description, it seems that you haven't used the lens too much. Am I right? If that's the case, I would recommend using it a bit more, and find out why you want to switch to a new lens. Make a list of situations you may be using your lens, and list of effects you want to achieve, then we can suggest a list of features that may be suitable. Until then, you should probably hold on to your cash.

Others may disagree with me on this, but I wouldn't recommend the EF-S17-85, even though it has a very nice focal range and IS. From my experience, its performance is not stellar by any means, and under certain conditions, not as good as the 18-55.

Your best bet is to get there early or even a day before and do a custom white balance for the areas you will be shooting.

I know how difficult it is. Depending on the place at which the ceremony is held, there may be multiple sources of different types of light, from natural sunlight through a skylight (that may or may not be stained), to incandescent chandeliers, to metal halide HID lighting, etc etc. So you may need multiple custom white balance grey card images. I don't have a 5D and do not know how easy it is to use multiple custom WB, but I'm guessing switching isn't easy. In that case, you can use custom WB for the most frequently shot areas, and switch to perhaps full auto for quick snap shots out of the same lighting zone.

Good luck and have fun!

Hi Antonio

I have not personally used the 16-35, but the picture looks alright to me. However, the focus does seem slightly off, Maria's facial features are out of focus, but the black picture frame is in sharp focus.

The edges and corners do seem somewhat soft at f/8....and the purple fringing is somewhat unimpressive -- that could be a feature of the camera though.

Hey Peter

Yup, I can confirm for my copy at least that it does have a problem when mounting on the tripod, but it's not always that visible. Usually, it's very noticeable when shooting at night.

Regardlessly, it's no big deal for me to just shut off the IS, same habit as yours.

So...anyway, the 24-105 does a swirl, eh? I'll be sure to see what kind of crazy effects it can pull when I actually get it back...dammit...it's been more than 2 weeks already.

Aha! I knew my mis-guided posts would come of use.

Jim, have a look at <a href="http://www.photo.net/bboard/q-and-a-fetch-msg?msg_id=00PMNn">this post</a>

I don't find it quite interesting, but it certainly has drawbacks for what I shoot. Have to run, but feel free to inquire more if you need.

Cheers

James

"Pros"...I feel intimidated answering this thread, but here's what I think anyway.

I have not used the Sigma 24-60/2.8, but from the MTF charts, it looks quite disappointing compared to the 24-70/2.8. However, it is less than $300 on eBay.

If you have the money, why not just go with the 17-55 and a 50/1.4? I have the 17-85, and I think I can relate to your reasons to replacing it. It's an okay performer at about 35mm to 50mm, but the wider-end gets quite interesting.

@ Chris

Since all responses alluded to focus, I assumed we are talking about focus. hehe...oops.

so, to Master Faster: define "quality". :)

Here's the second viewfinder shot.

This might help you find better focus in manual lenses.

I ended up restoring it to the original because I only have one M42 lens, and the rest are all auto's. So it ended up as an experiment more than anything else.<div></div>

I have one AF chipped adapter, but I didn't want to share it among the lenses, I'd rather have one adapter per lens for ease of mounting/dismounting. However, that would be very expensive if I had multiple M42 lenses.

Alternatively, I got an after-market split prism focus screen. I got one for my 30D thinking I would buy more M42 lenses. It works great. There are two draw backs that you have to be aware of (other than potentially damaging your camera).

1: The split prism semi-circles are quite distracting to me, and the mat is a little darker than the Canon stock screen, when I try to compose a shot.

2: my house isn't a clean room, so I got some dust into the focus screen area...(stupid me)

Other than that, it works marvelously. At about $30, it's probably worth a try， but you will be doing this at your own risk.

The following are view finder shots that I took while the focus screen is in place.<div></div>

Point taken, the white cloth is going to show up no matter what, but at least it's more uniform.

An alternative solution would be...since the marbles are so reflective, why not make good use of this property and create some interesting reflection shots? For example, colourful marbles side-lit at dawn, on an aged stone pedestal, in a foggy forest....

I have idea that might help, but don't know how well it will work for you. If anyone sees a flaw or improvement that can be made, post away, and let's make a better solution for Derrick.

The idea involves a home made light box (with white, light cloth) and wireless flash. Stretch the light box in an elongated way, and shoot from farther away with a longer lens. This way, the reflection of your lens would be much smaller, and perhaps negligible. See schematic below.

Would this be an option?<div></div>

You have to consider the differences in the following:

flexibility in depth of field: 2.8

ability to stop motion: 2.8

weight: 4

reach: 4 (24-105 has 35mm more)

handholdability: 4 (24-105 has a 3-stop IS that allows a shutter speed 2 stops slower than that of the 2.8-non IS lens).

price: 4 (16-35/2.8 is almost 2x as expensive than 17-40/4, and 24-70/2.8 is a coupla hundred bucks more than 24-104/4).

I have both the 17-40 and the 24-105, and are perfectly happy for what I shoot. For portraits and low light conditions I have a couple of fast primes - not as flexible, but will do the trick for me.

Also, you should also consider whether it's the 24mm end or 70mm end that you shoot more, because the 24-70/2.8' zoom is reversed - maximum extension at 24mm. So if you use 24mm more, you might find it a hassle to extend it every time.

I'm a little skeptical about this thing, perhaps my concerns are unjustified, but here's what I think of it.

If the device is generating both positive and negative ions, and blowing them all into the same space, wouldn't the ions just neutralize each other?

Also, what if the dust particles are physically stuck and not just bonded by electrostatic charge? This device would be rather ineffective then.

The sensor is an ESD sensitive device, I would think twice about putting something with a charge into the body of my camera.

Lastly, the language of the web page is not indicative of professionalism. The word "Stuff" is used quite a bit....nothing serious really. :P

Anyway, I'm just expressing my concerns. It's probably a very good product, but I wouldn't want to be the first one testing it out.