9 replies to this topic

[Decomike]

I want to replace my common lens to use it as a common lens on land and underwater on the Canon 10d. I read some reviews and both the Tamron 17-35 Di and Canon 17-40 L are looking good and covers the range i was looking for.

Can anyone tell me more about the Tamron, especially underwater? I already understand the 17-40 L is nice underwater but a Tamron is around $200 less. Is the Tamron really as sharp as the Canon and not soft like some Sigma lenses?
(I recently got the money to buy a Canon lens (100mm macro) and discover how sharp a picture can be )

[craig]

I have not shot either underwater but own both. I was disappointed with the overall performance of the 17-40 having been accustomed to Nikon wides before. I purchased the Tamron on the basis of the strong comments it received online but I don't think it performs nearly as well as the 17-40. My copy certainly does not. Based on my lens I wouldn't recommend the Tamron to anyone. Too much edge softness. I tested on a 1DMk2 with the intention of using it full frame, though. Perhaps on a 10D it may be suitable.

There's a big difference between Canon macros and Canon wides in terms of performance. Frankly, it's easy to find a good performing macro lens. The Canon 100 is one of those but mine refuses to focus down to 1:1. I only get .9 out of it. In contrast, every Nikon macro lens I own (except the zoom) exceeds 1:1, even the 60mm. Not a big matter but a disappointment nonetheless. I'm happy wih the range of Canon-mount macros I have but it's hard to get good magnification out of them.

[Torcidas]

I Have 17-40mm f4.0 L lens and must say that it is very good lens. Not perfect but very good.

I Take some climbing pictures with my 20D and this lens so you can check them out at
http://www.marulianu...wtopic.php?t=91

[whitey]

The 17-40L is a fine lens on 1.6 crop sensor cameras above water. Craig, I'm suprised you weren't happy with the performance, but perhaps you were using it on a full frame sensor? (otherwise, you likely had a bad copy - it's at least equal to the 20mm and 24mm Canon primes I've tested it against).

Underwater performance through the Ikelite dome (3305.50 I think) is good at the long end for 'macro' type work, and poor at the edges for wide angle. I'm sure this is a lens/port matching issue.

No personal experience with the Tamron.

[Decomike]

Because of your comment, whitey, i looked up the port list again on Ike's site and notice that i need the 5503.50. S**t then i also need an other port. I thought i got use the 5503.55 which i already own for the sigma 18-50. This one is longer and probably would not work at wide angle (?) and a 16-35 L is way to expensive.

(Ike, how far your return policy goes? Only use him ones. )

[craig]

I was testing he 17-40 with a 1D with the intention of using it full frame. Of course, the Canon 20 and 24 primes don't have good reputations either! My big compaint is the huge amounts of barrel distortion although there's more softness than I'd like. I'm accustomed to much better performance with Nikon's. The Tamron is nowhere near as good as the 17-40 though, at least my samples.

The Sigma 20/1.8 has a good online reputation but it is also very soft for me. Not impressed. The only wide for Canon I've liked is the 24-70L. It's huge but great.

[whitey]

Decomike, keep your 5503.55. I'm still struggling with the 17-40L in terms of getting acceptable sharpness U/W, and one of the things I've thought of trying is the 5503.55 port.

The 5505.50 has the dome very close to the front element, to the point that I managed to scratch the inside when testing a diopter. May main concern though is dome port position vs nodal point/entrance pupil of lens. The problem as I see it is that entrance pupil at 17mm is not at the right position relative to the 5503.50 dome. The 5503.55 may be worse, but then again it may be just right.

Using Canon lenses underwater is still uncharted territory in many respects. i think the Ikelite port chart is based on the physical dimensions of the lens, but I don't think it involves optical calculations (Ike, correct me if I'm wrong on this). We've also theorised that with the smaller diameter Ikelite ports, the match may have to be more exact than with a large dome port.

At this stage for me, the 17-40L plus 5503.50 performs more like a $50 lens than a $800 one, in terms of wide angle, which is what I'm trying to use it for.

Craig, Canon wides aren't great on the 1Ds Mk1 or 2. Sigma 20/1.8 has marked sample variation. Zeiss 21mm is generally considered the best peformer, but isn't really suited to underwater use. 24/1.4L is an OK performer. I own the 24/2.8, which no one seems to bother testing on the 1Ds (never seen it done), but which I used to consider very sharp when shooting film. My next wide purchase will be the 24mm TS-E, but I don't see that listed on the Ikelite port chart

[craig]

I agree the 24mm might be OK full frame. I may stick to the 24-70 which works well. My Sigma is not very good.

[Decomike]

Sorry for the late response ....

Whitey, i will try the lens / port combination and post my results when possible.
Maybe i try to rent a 17-40 first if possible.

[Decomike]

I find a nice priced secondhand 17-40L so i went for this one.
Yesterday i made some pictures with the 5503.55 dome and the 17-40L from Canon. You can find hem here.