Better for digiscoping - Large obj. non-ed scope or small obj. ed? (1 Viewer)

[Jaff]

Better for digiscoping - Large obj. non-ed or small obj. ed scope?

After reading this thread

http://www.birdforum.net/showthread.php?t=59877

I was wondering what is the general consensus on what is better for digiscoping, ED glass (or it's equivalent) or a large objective lens. So for example, a Leica Televid APO 62 versus a Televid 77 or Kowa 603/4 versus a TSN 821/2 M. The smaller ED scopes in general are priced about £100-150 more than the larger scopes (Warehouseexpress) but my feeling is the larger objective would be better.

This is because the extra light that the larger scopes are gathering would give the camera an easier time in acquiring a good focus on the subject and thus giving more consistently sharp images. In my (very limited) understanding the purpose of ED glass etc. is to reduce CA and from my experience it is something that only really becomes a problem in the minority of photos taken.

In short, I think I'd happily have some CA so long as the photo was sharp. Any thoughts? :h?:
Jaff

 

[iporali]

I was wondering what is the general consensus on what is better for digiscoping, ED glass (or it's equivalent) or a large objective lens.

Jaff,

I am afraid there is no general consensus on this. It - again - depends on your way of digiscoping. I can see two different cases when different solution is better.

A. If you are ready/willing/capable of getting closer to the subject, the smaller ED-objective is better - especially in Leica/Zeiss cases when the power is correspondingly lower. This means that the brightness (exit pupil) remains the same, but to get the bird in the same size, you have to get closer. In Swarovski's case you get the same power, but lose in brightness. I think Swaro shouldn't sell non-HD versions at all.

B. If you can't walk closer, you often lose the advantage of ED, because to get similar pics, you will get longer exposure times (due to small objective) - and the risk of blurred pics increases. Also the eye-relief of the zoom becomes shorter if you have to zoom with the eyepiece (often leading to increased vignetting).

In my opinion you are capable of getting better pics with the small ED-objective than the large non-ED, but this works mainly at closer distances, and you may have to work more to get there (and it is not always possible). If you are not disturbed with CA and just digiscope to document your observations from certain spots, the larger non-ED may work better. I would always take the ED, however. :t:

Best regards,

Ilkka

 

[Neil]

You raise and interesting question. I have the non-fluorite Kowa 821M and was very pleased with the images I got in most situations. I did notice a difference when I upgraded to my current ED glass scopes, in the order of 10% but at twice the price. When photographing at closer distances (less than 30 meters ) the differences would not be so noticable but at longer distances they were. I haven't used a 65mm scope so I can't comment on them, although I would like one for closeup work. With the newer digiscoping capable cameras being faster than
the old generation (eg Fuji F30) the loss of light is not so important. Maybe someone who has both types of scope could do a test for us. Neil.

 

[digitalbirdy]

Re: Small ED or big non ED

I am a keen birder and a VERY keen photographer.
I use a Fuji F10 and F11. These cope with low light levels very well.
My photogrpahic experiences with non ED scopes was okay of a sort. But not earth shattering. Eventually I purchased a 66mm ED scope and the results have been stunning - when I have the strength to carry it! (its a lot heavier than my 65mm non ed scope.)

As non ed scopes tend to blur images by there very nature, slightly more accurate focussing is academic. ED scopes produce very sharp images. If you can focus your scope okay, the camera should always capture a more professional quality image.
...BUT, I would say this. If seeing the bird is more important - especially in very dark conditions - such as dawn and dusk, then you may be better off with a very large non ed scope. Just dont expect razor sharp images from it.

Of course i am generalising to an extent, as I have not personally tried a $1000 non ed scope and I expect they are much better than my cheaper one. But I suspect if you had that sort of cash to splash, this whole question would not be an issue anyway!

My $750 ed scope is awesome. I do sometimes still take out a small non ed which fits in my pocket easily - and its great for looking through, but I always regret it when i take photos through it.

best of luck.

Adrian