Trogon Photo Tours

September 2020 - This month's article is about iso selection and features images from our Galveston, Texas workshops.  My starting point for iso selection is I typically use the highest iso's on my cameras which in my opinion produce very good image quality with little noise.  For full frame cameras this is typically iso 800 to 1250, while when I used cropped frame sensors such as the 7D2 it was more in the 400 to 500 iso range. 

Here's a female Painted Bunting we photographed from the blind at Stevenson Woods in Galveston.  The settings are Canon 5D4 500F4 1/500 F5.6 at iso 1250, Av mode, evaluative metering at -0.3, Gitzo Tripod, Wimberley Head.  My default settings for iso when using the two Canon full frame bodies I work with are between iso 800 and 1250.  At those isos I still get very good image quality.  Any lower of an iso on this shot and I would have been losing valuable shutter speed and depth of field.  I generally try to keep enough shutter speed to get action photographs but the light was starting to get lower here so I just opted for plenty of shutter speed to ensure a good portrait.  1/500 is plenty of shutter speed for a static shot and some shots if the bird is moving a bit.   

Here's a male Baltimore Oriole photographed on the same perch about 30 minutes later.  The settings are 1/500 F6.3, iso 1600, Av mode, evaluative metering -0.7.  For this image the light had continued to drop a bit so I increased my iso to 1600.  I also wanted a bit more depth of field and I dialed in more negative exposure compensation to keep from blowing out the orange plumage against the dark background. 

Here are a pair of Rose-breasted Grosbeaks that I photographed a little bit after the Baltimore Oriole.  The settings for this shot are Canon 5D4 500F4 1/1000 F6.3, iso 3200, Av mode, evaluative metering -1.0, Gitzo Tripod, Wimberley Head.  You will notice that the settings are similar to the prior shot but both the shutter speed and iso are doubled.  The reason I bumped up my iso at this point is on this perch there were often squabbles and I was trying to make sure I had enough shutter speed to stop the action during any disputes.  By increasing the iso from 1600 to 3200 I also increased my shutter speed from 1/500 to 1/1000.  To hold the whites against that dark background I dialed in -1.0 on the exposure compensation. 

I photographed this Gray Catbird and Baltimore Oriole about 40 minutes after the grosbeak shot.  The techs were 1/640 F5.6, iso 3200, Av mode, evaluative metering -1.0.  So at this point I had lost another stop of light as my shutter speed had decreased to 1/640 and I dropped my F-stop to F5.6.  But I didn't increase my iso as I think I lose too much image quality typically if I go over iso 3200.  It turned out that I had just enough depth of field and shutter speed for this one to work out. 

Here's a female Wilson's Plover photographed during our Galveston trip.  Canon 5D4 100-400 with 1.4x teleconverter at 560mm, 1/3200 F9, iso 800, Av mode, evaluative metering -0.3, handheld while lying on the ground.  When I am photographing waterbirds, raptors etc out in the open, generally my starting point with my iso is at 800.  In this example with a bird standing still I certainly could have dropped the iso down to a lower level such as 400 but if the bird had taken off or started running I may not have had the shutter speed to get a sharp image and at iso 800 the image quality is already very good.  So it's fairly unusual for me with these full frame cameras to drop the iso below 800. 

Here's an example of why I don't drop iso, this male Wilson's Plover is really moving.  The techs are almost the same as the previous shot except this was at 1/2500 as it was a bit earlier in the morning so the light was a little bit lower.  Also note on these shots I am at F9 because with the teleconverter on the 100-400 I start out at F8 and I want to stop down a bit.  

Here's a Willet with a crab photographed at the east end of Galveston Island.  The techs on this shot are Canon 5D4 500F4 1/5000 F6.3, iso 500, Av mode, evaluative metering at -0.3, handheld.  This is one of the few times recently that I have dropped my iso down below 800.  The reasoning here is we were shooting midday with quite bright light and heat haze and I knew I would be cropping the image a fair bit.  To maintain very good image quality I dropped the iso down. Even at iso 500 I was getting 1/5000 shutter speed, which was more than enough even if the Willet took off with the crab.  Since I was photographing with my 500F4 lens, F6.3 gave me plenty of depth of field with just one bird.  So in this situation there really was no reason not to drop the iso down.  I would add that I would normally not be photographing at that time of day in that bright light, but we were looking for some species we had missed for our participants including American Oystercatcher which we did find. 

Here we are back at Stevenson Woods.  I photographed these juvenile male Baltimore Orioles there this spring and we had more sunshine than during the 2019 workshop.  The settings for this shot were Canon 1DX2 500F4 1/2500 F8, iso 1250, Manual exposure, Gitzo tripod, Wimberley Head.  These two young male Baltimore Orioles had a long dispute over this perch which was above the water drip.  At iso 1250 I had plenty of shutter speed and depth of field to get both of them sharp and in focus.  They were fluttering around so I needed a fair bit of speed and they were fairly close so I wanted to make sure I had enough depth of field for both of them.

Here's a Baltimore Oriole and a Northern Cardinal having a tussle.  The techs for this shot were 1DX2, 500F4 1/2000 F6.3, iso 1250, manual exposure, Gitzo tripod, Wimberley Head. 

Every year we get some Tanagers during our May Galveston workshop.  Usually it's Summer and Scarlet Tanagers, but this spring it was mostly Western Tanagers.  The techs for this shot were Canon 5D4 500F4 1/160 F5.6, iso 1250, Av mode, evaluative metering at 0.  Despite the fact the light was quite low I took this image at the same iso as the previous two shots which were taken during sunshine.  The reason is when I'm on the tripod and the bird is not moving I am able to take a sharp image down to about 1/125 of a second and sometimes at slower shutter speeds.  So for a portrait I will often photograph at a relatively slow shutter speed if the light is low to keep good image quality.  If I had been trying for an action shot I would have to have been at a much higher iso.  I would also note that at this point I had changed from the 1DX2 to the 5D4.  The 1DX2 is great for action at 14 frames per second versus 7 for the 5D4, but the 5D4  has better resolution at 30 megapixels versus 20 for the 1DX2 so if I am photographing in low light with little to no chance of action photography I will go with the 5D4.

Here's a Northern Parula from last year's trip.  This was taken just before dusk and the settings were Canon 5D4 500F4 1/125 F5.6, iso 2000 Av mode, evaluative metering at 0, Gitzo Tripod, Wimberley Head.  In this case I had to bump up the iso to get any sharpness as the bird was moving and it was getting quite dark.  The head is not tack sharp but sharp enough I think. In this case I could have increased my iso 3200 and gotten more speed, in the end I think the image would have looked about the same but I would have had to be a bit more aggressive with noise reduction. 

To summarize I like to use the highest iso's my camera can handle and still produce excellent image quality for bird photography.  This way I am maximizing my ability to take action and behavioral shots while at the same time maintaining good image quality.  Of course this is for typical bird photography, there are specialized times when I will use a lower iso such as for some types of hummingbird photography and for artistic blur shots.  If necessary to get the image I want I will bump the iso up to between 1600 and 3200 but I rarely go over iso 3200 due to deterioration of image quality.