Pushing Ilford HP5+ to ISO 800

Since I began my woodlands project last fall I have struggled with keeping shutter speeds short. I suffer in many cases with light breezes that threaten to move foliage and ruin the shot. I moved quickly from Ilford FP4+ (125 ISO box speed though I shoot at ISO 80) to HP5+ (400 ISO). Frustrated one day I decided to meter a scene on a sheet of 4x5 film at 800 and develop it accordingly. I reasoned better a grainier image than a blurry one. Also sheet film has the advantage of changing the development on an image by image basis. 

I looked up Massive Dev chart for HC-110 dilution B (1+31) for HP5+ pushed to 800 ISO. There are two formulas but I went with 10 minutes at 20C and never looked back. I have now run a number of sheet and roll films through this and have not been disappointed. In fact I see almost no need to go back. Most images scan well and print in the darkroom as well.  As for grain, I can't see much difference. Certainly shooting medium and large format makes any increased grain less consequential than say 35mm would. My subject matter is also helpful as I am shooting intimate landscapes with little in the way of skies or other broad single tone areas where grain seems more prominent. 

Evaluating the Grain

I have take a couple of examples of sky that were developed at 400 and 800 ISO and cropped out the sky portion.  

Source Images (3200dpi)
ISO 400 left ISO 800 right

Next I cropped similar areas of sky with comparable tone. If anything the 400 ISO section on the left looks grainier. 

Sky Crop (3200 dpi 750x750pixels)
ISO 400 left ISO 800 right

I then took these sections and used Photoshop levels to maximize contrast so grain becomes more apparent. (Note there is some dust present particularly in the image on the left that shouldn't be confuse for grain.) Here I would argue they are the same grainwise. 

Sky Crop High Contrast
ISO 400 left ISO 800 right

Next I made another crop of 64x64 pixels of comparable sections. 

Zoom to show grain (64x64 pixels)
ISO 400 left ISO 800 right

For my eyes there are very few differences. 

Additionally I am satisfied with the shadow detail where pushing might show some weakness. I have not made any rigorous comparisons however. I am probably under-exposing when I shoot HP5+ at box speed. I have not gone to the trouble to determine the optimum exposure and developing for HP5+ like I did for FP4+. I have noted that many people shoot HP5+ around 320 ISO (much as I shoot FP4+ at ISO 80 vs box speed of 125.) so perhaps it is not surprising I am not seeing much difference in shadow detail between the two.