Focusing issues with the C-7070

[ejg62]

Thanks for the information.

Below is a quote from a review on the C-7070 on dcresource.com. The reviewer also experienced some issues with focusing in lower light (compared to the 5060) even though they supposedly have the same focusing mechanism.

In normal lighting, focus speeds were quite good, typically around 0.3 - 0.5 seconds. If the camera has to hunt to lock focus then it can take closer to a second. Despite that fancy dual focusing system, I wasn't overly impressed with the C-7070's low light focusing abilities. That's strange, because the old C-5060WZ did pretty good in my tests. Who knows? by Jeff Keller, DCRP Founder/Editor
Originally posted: March 21, 2005
Last Updated: March 21, 2005

Jim G

 

[Fota]

I have an 7070 and I agree that its AF is crap.
I have learned how to take razor sharp shots even in green water with bad viz, but I still consider the 7070 AF crap. It's very slow and there are many many situations (e.g. several types of material/animal) that it simply doesn't handle.
I mostly shoot macro or super macro.
I use the DS-125 pointer light as focus light, but I've just bought a dedicated focus light (not yet tested). I don't expect the AF results to be better but at least it gives me freedome to point the flash away from the subject.

On land I've compared it to Nikon F50 and Canon 350D. Both with cheap kit lenses.

There was no question about it. Both cameras were soooo much better than the 7070. I tested especially on soft cloth (e.g. blankets), transparent material (e.g. colored glass). I did it indoor with lots of natural light. I tested on short distants, <= 2 feet.
Typical underwater subjects but more light than what I get uw. 7070 often completely failed or was dead slow. Both F50 and 350D focused fast and exact. Only when zooming in to their extreme the AF was a little slow. And then one should note that both Nikon and Canon users all claim that their cheap kit lenses have bad and slow AF! F50 is an old and very cheap SLR (but sure, analog cameras were generally good at AF).


/Fota

 

[AndyT]

There is definitely an improvement in AF with a focus light - which one did you buy ?

 

[Fota]

There is definitely an improvement in AF with a focus light - which one did you buy ?

After reading lots of tests and user comments I ended up getting an Ikelite Mini C.
Why?

* It's well build
* lots of output
* long battery life
* very cheap
* small enough
* ULCS makes a nice holder for my Ikelite handle, so I can move the strobes without altering the focus light position.

BUT, it's beam for a focus light sucks big time. Well, I knew this ;-) and got a smart recommendation from reefphoto to buy a diffuser (Fisheye Clear Diffuser for LED48DX LIGHT) as it fits perfectly and converts the beam into a very nice and smooth beam perfect for a focus light. The diffuser costed more than the mini c but who cares. ;-) It's a very nicely priced packaged nevertheless. I was thinking that if I'm still unhappy with it, I'll go for the Fisheye LED48DX LIGHT, and then I'll have to get the diffuser anyway.

I have not received it or tested it yet but I've read a review (made by reefphoto) that shows a picture of its beam, before and after the diffuser and compared to several expensive focus lights (Fisheye LED48DX LIGHT etc).


/Fota

 

[ejg62]

I think I need to look into a focu light. There is a big difference in price between the Ikelite Mini C and Fisheye LED48DX ($35 vs $289, USD). For that price the fisheye should work better than the Mini C.

Andrew - what do you use as a focus light?

Jim G

 

[AndyT]

Jim

I use the Fisheye 20w halogen. I also have a Fantasea 44 LED and it doesn't do 1/2 the job that the Fisheye does .

Warning - if left on full brightness the battery on the Fisheye only lasts 40 min . It also only has a bulb life of less than 50 hrs. I still think it's worth the money.

 

[Fota]

I think I need to look into a focu light. There is a big difference in price between the Ikelite Mini C and Fisheye LED48DX ($35 vs $289, USD). For that price the fisheye should work better than the Mini C.

Andrew - what do you use as a focus light?

Jim G

Note that the Mini C without the diffuser is worthless as a focus light. And note that the diffuser costs $50.00.


/Fota

 

[ejg62]

Fota

It has been several weeks since the previous note you mentioned the Mini C focus light, have you had an opportunity to test it? If so, how did it work? Did it meet your requirements or will you upgrade to the Fisheye LED48DX light. I would be intersted in knowing.

Thanks

Jim G

 

[jlyle]

Why pay $50 for a diffuser? Cut a circle from a plastic milk carton and insert it inside the lens of your Mini C. The alternative is to crumple some aluminum foil and line the inside of the silvered-plastic cone...

 

[PharmDMark]

I too have been trying to decide on a focus light. After looking at the pictures of focus lights in the article on Reef photo/video, I begain experimenting with the UK SL4 which I already owned. I was able to secure a round piece of a coffee can lid over the outside of the light. The result is very similar to the picturs of the Ikelite mini C with fisheye diffuser. I haven't yet tried it underwater, but it seems to work pretty well topside, especially once I add a WAL which blocks the cameras AF light.