Canon Powershot A540

[Szabi]

Dear Digiscopers,

I'm looking for some help. Do you have any experience with that camera? Does any of you use it? I'm especially interested in teh combination of it with KOWA TSN823. I would like to see some digiscoped photos taken by this camera (the best would be through that scope).
Thank you for your help!
Szabi

[rmel66]

Dear Digiscopers,

I'm looking for some help. Do you have any experience with that camera? Does any of you use it? I'm especially interested in teh combination of it with KOWA TSN823. I would like to see some digiscoped photos taken by this camera (the best would be through that scope).
Thank you for your help!
Szabi

Please check the following webpage for picture taken with a canon 540 and orion 127mm mak scope.
http://www.buytelescopes.com/gallery/view_photo.asp?pid=11896&sg=4

Rmel66

[twegier]

I have very recently started digiscoping and just joined BirdForum (its my first post; hi, everybody). I am using A540 and after a few testings, I think I am ready to share my opinion on this camera with you. It is probably to late to help Szabi decide whether to buy this camera, but maybe my post will be useful for other people considering A540, or its successors like A570 IS. Apart from the camera, my setup consists of Zeiss 65T FL with 23x eyepiece, adapter tube (from Soligor, for A510/520) and a big version of the FoxFoto F-adapter (however, I cannot really recommend here the F-adapter for the Zeiss eyepiece - as it is, it can't be firmly attached to this eyepiece. I had to "improve" it).
A540 for digiscoping. Pros:
- In my opinion, good picture quality (however, I did not compare it with any other camera for digiscoping). Most digiscoped pictures are very far from being perfect, but I have to admit that some of them pleasantly susprised me. They were apparently sharp when viewed on full screen, and still acceptable when examined at actual size.
- full manual control. Most often I use aperture priority mode and manual focus. I prefer to focus manually, but the auto focus usually works reliably as well.
- custom timer. Great feature, possibly the biggest advantage of this camera. You can customize the delay between pressing the shutter and taking the picture depending on how much time it takes for vibrations to cease. In addition, you can define the number of pictures taken with the custom timer. I usually take two.
- the camera is fast and responsive, not sluggish at all.
- the camera can take filter/lens adapters, giving more options for connecting the camera to the scope.
- no problem with vignetting, at least at middle and long focal lengths, with the Zeiss scope.
Cons:
- it is one of those cameras with a small sensor (1/2.5"), which potentially can lead to higher noise. I try to stay at ISO 100.
- akward lens behaviour. The lens is extended at wide angle, then during zooming it retracts, and extends again at tele. It probably makes the middle focal range most optimal for digiscoping, but at the same time it creates the danger of hitting the eyepiece when the camera accidently shuts down (the lens extends fully before shutdown).
- low resolution screen (85k) - it is really a bit low. Sometimes, especially with too much light from the back, manual focusing is mostly guessing. Luckily, the central portion of the image can be enlarged during manual focus.
- no on-screen indication of the zoom position, which may be a bit problematic when using a closed adapter, when the zoom position cannot be even estimated by eye. I overcome this problem by observing the largest possible aperture, which of course changes with zooming.
In summary, I think it is a very good camera for digiscoping, especially if it is stably connected to the scope through an adapter. Then one can really take advantage of its features, like custom timer or manual focus. On the other hand, it is probably not the best choice for hand-held digiscoping photography. Although it has 4x optical zoom, I did not find vignetting to be a problem, at least with the huge Zeiss eyepiece that I use (I cannot exclude that with smaller eyepieces, and especially when hand-held, the vignetting may appear). Below are two pictures taken with my setup. Apart from the resampling to 800x600 and adjusting the levels (I usually take pictures with -2/3 exposure compensation, so the original pictures are a bit dark), I did not modify them in any way.

[Neil]

Twegier, Very nice report, thanks, Neil.

[twegier]

Thanks Neil. I noticed that there are not so many reports about using A500 series. Digiscopers rather try using Powershots from A600 series and frequently complain about vignetting. A540 has a smaller sensor than e.g. A640, and therefore may be more digiscoping friendly (less vignetting). On the other hand, I predict that, for the same reason, the picture quality of A540 can be lower than that of A640.
Neil, you have tested lots of digiscoping equipment, including cameras as A640, Fuji F30, Sony W100, and your digiscoping pictures are one of the best I've seen (at the moment I can only dream about such quality). I know that you were not that happy with A640 because of vignetting, low resolution screen etc. But when it comes to picture quality only, let's say at ISO100, was the quality of pictures digiscoped through the above mentioned cameras comparable, or there were clear differences? twegier

[Neil]

Neil, you have tested lots of digiscoping equipment, including cameras as A640, Fuji F30, Sony W100, and your digiscoping pictures are one of the best I've seen (at the moment I can only dream about such quality). I know that you were not that happy with A640 because of vignetting, low resolution screen etc. But when it comes to picture quality only, let's say at ISO100, was the quality of pictures digiscoped through the above mentioned cameras comparable, or there were clear differences? twegier[/QUOTE]

Twegier,
I try to keep up with the latest camera technology but it is getting difficult with so much choice out there these days. That's the main reason I like BirdForum as there are lot's of other enthusiatic digiscopers out there trying new things - like the Canon A series.
At iso 100 the images from the A640 are amongst the best I've seen from a digiscoping camera. I have got mine to work with little vignetting by having a special adapter built. You could probably do this with the G6 too but I'm not sure about the G7. The Nikon 8400 is still my camera of choice when out in the field due to it's Electronic Viewfinder which on a straight scope makes getting on the bird much faster and focusing much quicker. The A640 is the worst at this of all the cameras I have due to the low resolution screen. I get more images out of focus with this camera than any other ( I still use it every day though as the long lens and 10 megs on the Canon sensor can give you a great digiscoped image ). The Fuji F30/31 is my camera choice for speed when there is action around (little egrets fighting for instance ) and at iso 100 it's image quality is just behind the 8400 and the 640 but at iso 400/800 it leaves them for dead and at iso 1600 it has no competitors.
The new P5000 also has a very sharp lens, on a par with the 640 and maybe even sharper than the 8400 (according to DPReview ) and my initial impressions are that it will make a good digiscoping camera if speed is not important, particularly on an angled scope (no rotatable screen ).
Overall , if I put the best images from these cameras , including the Olympus 7070wz you would see very little difference when cropped and reduced for email. Maybe only 10% from best to worst. But of course a 10 meg image is going to print up much bigger and give you more room to crop.
I just wish the A640 had the P5000 screen.
Neil